Background

Chronic Heart Failure
Patients with chronic heart failure are at risk of developing acute decompensated heart failure, often requiring hospital admission. Patients with a history of acute decompensation have the additional risk of future episodes of decompensation and death. Reasons for the transition from a stable, chronic state to an acute, decompensated state include disease progression, as well as acute events such as coronary ischemia and dysrhythmias. While precipitating factors are frequently not identified, the most common preventable cause is noncompliance with medication and dietary regimens.^1,

Management

Strategies for reducing decompensation, and thus the need for hospitalization, are aimed at early identification of patients at risk for imminent decompensation. Programs for early identification of heart failure are characterized by frequent contact with patients to review signs and symptoms with a health care provider, education, and medication adjustments as appropriate. These encounters may occur face-to-face in the office or at home, or via cellular or computed technology.^2,

Precise measurement of cardiac hemodynamics is often employed in the intensive care setting to carefully manage fluid status in acutely decompensated heart failure. Transthoracic echocardiography, transesophageal echocardiography, and Doppler ultrasound are noninvasive methods for monitoring cardiac output on an intermittent basis for the more stable patient but are not addressed herein. A variety of biomarkers and radiologic techniques may be used for dyspnea when the diagnosis of acute decompensated heart failure is uncertain.

The criterion standard for hemodynamic monitoring is pulmonary artery catheters and central venous pressure catheters. However, they are invasive, inaccurate, and inconsistent in predicting fluid responsiveness. Several studies have demonstrated that catheters fail to improve outcomes in critically ill patients and may be associated with harm. To overcome these limitations, multiple techniques and devices have been developed that use complex imaging technology and computer algorithms to estimate fluid responsiveness, volume status, cardiac output and tissue perfusion. Many are intended for use in outpatient settings but can be used in the emergency department, intensive care unit, and operating room. Four methods are reviewed here: implantable pressure monitoring devices, thoracic bioimpedance, inert gas rebreathing, and arterial waveform during the Valsalva maneuver. Use of the last 3 is not widespread because of several limitations including use of proprietary technology making it difficult to confirm their validity and lack of large randomized controlled trials to evaluate treatment decisions guided by these hemodynamic monitors.

Regulatory Status
Noninvasive Left Ventricular End-Diastolic Pressure Measurement Devices

In 2004, the VeriCor^® (CVP Diagnostics), a noninvasive left ventricular end-diastolic pressure measurement device, was cleared for marketing by U.S. Food and Drug Administration (FDA) through the 510(k) process. The FDA determined that this device was substantially equivalent to existing devices for the following indication:

"The VeriCor is indicated for use in estimating non-invasively, left ventricular end-diastolic pressure (LVEDP). This estimate, when used along with clinical signs and symptoms and other patient test results, including weights on a daily basis, can aid the clinician in the selection of further diagnostic tests in the process of reaching a diagnosis and formulating a therapeutic plan when abnormalities of intravascular volume are suspected. The device has been clinically validated in males only. Use of the device in females has not been investigated."

Thoracic Bioimpedance Devices

Multiple thoracic impedance measurement devices that do not require invasive placement have been cleared for marketing by the FDA through the 510(k) process. The FDA determined that this device was substantially equivalent to existing devices used for peripheral blood flow monitoring. Table 1 presents an inexhaustive list of representative devices (FDA product code: DSB).

Table 1. Noninvasive Thoracic Impedance Plethysmography Devices

Device	Manufacturer	Clearance Date
BioZ® Thoracic Impedance Plethysmograph	SonoSite	2009
Zoe® Fluid Status Monitor	Noninvasive Medical Technologies	2004
Cheetah Starling SV	Cheetah Medical	2008
PhysioFlow® Signal Morphology-based Impedance Cardiography (SM-ICG™)	Vasocom, now NeuMeDx	2008
ReDSTM Wearable System	Sensible Medical Innovations	2015

Also, several manufacturers market thoracic impedance measurement devices integrated into implantable cardiac pacemakers, cardioverter defibrillator devices, and cardiac resynchronization therapy devices. Thoracic bioimpedance devices integrated into implantable cardiac devices are not addressed in this policy

Inert Gas Rebreathing Devices

In 2006, the Innocor^® (Innovision), an inert gas rebreathing device, was cleared for marketing by the FDA through the 510(k) process. The FDA determined that this device was substantially equivalent to existing inert gas rebreathing devices for use in computing blood flow. FDA product code: BZG.

Implantable Pulmonary Artery Pressure Sensor Devices

In 2014, the CardioMEMS™ Champion Heart Failure Monitoring System (CardioMEMS, now Abbott) was approved for marketing by the FDA through the premarket approval process. This device consists of an implantable pulmonary artery (PA) sensor, which is implanted in the distal PA, a transvenous delivery system, and an electronic sensor that processes signals from the implantable PA sensor and transmits PA pressure measurements to a secure database.^3, The device originally underwent FDA review in 2011, at which point FDA found no reasonable assurance that the monitoring system would be effective, particularly in certain subpopulations, although the FDA agreed this monitoring system was safe for use in the indicated patient population.^4,

Several other devices that monitor cardiac output by measuring pressure changes in the PA or right ventricular outflow tract have been investigated in the research setting but have not received the FDA approval. They include the Chronicle® implantable continuous hemodynamic monitoring device (Medtronic), which includes a sensor implanted in the right ventricular outflow tract, and the ImPressure® device (Remon Medical Technologies), which includes a sensor implanted in the PA.

Note: This evidence review only addresses the use of these technologies in ambulatory care and outpatient settings.

Related Policies

• None

a. With proven or suspected disease involving severe regurgitation of the aorta;
b. With minute ventilation (MV) sensor function pacemakers, since the device may adversely affect the functioning of that type of pacemaker;
c. During cardiac bypass surgery; or,
d. In the management of all forms of hypertension (with the exception of drug- resistant hypertension

For members enrolled in Medicaid and NJ FamilyCare plans, Horizon BCBSNJ applies the above medical policy.

FIDE SNP:

For members enrolled in a Fully Integrated Dual Eligible Special Needs Plan (FIDE-SNP): (1) to the extent the service is covered under the Medicare portion of the member’s benefit package, the above Medicare Coverage statement applies; and (2) to the extent the service is not covered under the Medicare portion of the member’s benefit package, the above Medicaid Coverage statement applies.

Policy Guidelines: (Information to guide medical necessity determination based on the criteria contained within the policy statements above.)

This policy refers only to the use of stand-alone cardiac output measurement devices designed for use in ambulatory care and outpatient settings. The use of cardiac hemodynamic monitors or intrathoracic fluid monitors that are integrated into other implantable cardiac devices, including implantable cardioverter defibrillators, cardiac resynchronization therapy devices, and cardiac pacing devices, is not addressed in this policy.


[RATIONALE: This policy was created in 1999 and has been updated regularly with searches of the PubMed database. The most recent literature update was performed through March 9, 2020.

For the first indication, because there is direct evidence from a large randomized controlled trial (RCT), we focus on it and assess the evidence it provides on clinical utility. Evidence reviews assess the clinical evidence to determine whether the use of technology improves the net health outcome. Broadly defined, health outcomes are length of life, quality of life, and ability to function-including benefits and harms. Every clinical condition has specific outcomes that are important to patients and managing the course of that condition. Validated outcome measures are necessary to ascertain whether a condition improves or worsens; and whether the magnitude of that change is clinically significant. The net health outcome is a balance of benefits and harms.

To assess whether the evidence is sufficient to draw conclusions about the net health outcome of technology, 2 domains are examined: the relevance, and quality and credibility. To be relevant, studies must represent one or more intended clinical use of the technology in the intended population and compare an effective and appropriate alternative at a comparable intensity. For some conditions, the alternative will be supportive care or surveillance. The quality and credibility of the evidence depend on study design and conduct, minimizing bias and confounding that can generate incorrect findings. The RCT is preferred to assess efficacy; however, in some circumstances, nonrandomized studies may be adequate. RCTs are rarely large enough or long enough to capture less common adverse events and long-term effects. Other types of studies can be used for these purposes and to assess generalizability to broader clinical populations and settings of clinical practice.

For indications 2, 3, and 4, we assess the evidence as a medical test. Evidence reviews assess whether a medical test is clinically useful. A useful test provides information to make a clinical management decision that improves the net health outcome. That is, the balance benefits and harms is better when the test is used to manage the condition than when another test or no test is used to manage the condition.

The first step in assessing a medical test is to formulate the clinical context and purpose of the test. The test must be technically reliable, clinically valid, and clinically useful for that purpose. Evidence reviews assess the evidence on whether a test is clinically valid and clinically useful. Technical reliability is outside the scope of these reviews, and credible information on technical reliability is available from other sources.

Implantable Pulmonary Artery Pressure Monitoring
(CardioMEMS Device)

Clinical Context and Therapy Purpose
The purpose of the CardioMEMS system in patients who have heart failure is to provide remote monitoring for early symptoms of heart failure in order to modify therapy and prevent or reduce hospitalization.
The question addressed in this policy is: Does use of an implantable pulmonary artery sensor device (CardioMEMS) improve net health outcomes in individuals with heart failure in the outpatient setting?
The following PICO was used to select literature to inform this policy.

Patients
The relevant population(s) of interest is patients with New York Heart Association (NYHA) Class III heart failure who have had a hospitalization in the past year

Interventions
Left ventricular end-diastolic pressure (LVEDP) can be approximated by direct pressure measurement of an implantable sensor in the pulmonary artery wall or right ventricular outflow tract. The sensor is implanted via right heart catheterization and transmits pressure readings wirelessly to external monitors. One device, the CardioMEMS Champion Heart Failure Monitoring System, has approval from the U.S. Food and Drug Administration (FDA) for the ambulatory management of heart failure patients. The CardioMEMS device is implanted using a heart catheter system fed through the femoral vein and generally requires patients to have an overnight hospital admission for observation after implantation.

Comparators
The comparator of interest is standard clinical care without testing.
Patients with heart failure are managed by cardiologists in an outpatient clinical setting.

Outcomes

The International Consortium for Health Outcomes Measurement has identified 3 domains of outcomes for a standard outcome set for patients with heart failure.^5,

• Survival and disease control (ie, mortality)
• Functioning and disease control (ie, symptom control including dyspnea, fatigue and tiredness, disturbed sleep, and peripheral edema, activities of daily living including health-related quality of life, maximum physical exertion, independence and psychosocial health including depression and anxiety, confidence and self-esteem)
• Burden of care to patient (ie, hospital visits including admissions and appointments, treatment side effects, complications)

Measurements of maximal oxygen consumption during exercise, the 6-minute walk test, stair climb test, Short Physical Performance Battery or hand-grip strength are functional measures.

Patient-reported outcome measures include the Kansas City Cardiomyopathy Questionnaire, the NYHA Functional Classification, Minnesota Living with Heart Failure Questionnaire.

Generally, demonstration of outcomes over a 1-year period is meaningful to assess outcomes for the intervention.

Study Selection Criteria
Methodologically credible studies were selected using the following principles.

• Comparative controlled prospective trials were sought, with a preference for RCTs.
• In the absence of such trials, comparative observational studies were sought, with a preference for prospective studies.
• To assess long-term outcomes and adverse effects, single-arm studies that capture longer periods of follow-up and/or larger populations will be considered.
• Larger sample size studies and longer duration studies are preferred.
• Studies with duplicative or overlapping populations were excluded.

Abraham et al (2011, 2016) have reported on the results of the CardioMEMS Heart Sensor Allows Monitoring of Pressure to Improve Outcomes in NYHA III Heart Failure Patients trial (CHAMPION), a single-blind RCT in which all enrolled patients were implanted with the CardioMEMS device.^7,8,Patients were randomized to the CardioMEMS group, in which daily uploaded pulmonary artery pressures were used to guide medical therapy, or to the control group, in which daily uploaded pressures were not made available to investigators and patients continued to receive standard of care management, which included drug adjustments in response to patients' clinical signs and symptoms. An independent clinical endpoints committee, blinded to the treatment groups, reviewed abstracted clinical data and determined if hospitalization was related to heart failure hospitalization. The randomized phase ended when the last patient enrolled completed at least 6 months of study follow-up (average, 18 months) and was followed in an open-access phase during which investigators had access to pulmonary artery pressure for all patients (former control and treatment group). The open-access phase lasted for an average of 13 months. In the randomized phase of the trial, if the investigator did not document a medication change in response to an abnormal pulmonary artery pressure elevation, a remote CardioMEMS nurse could send communications to the investigator related to clinical management. No such activity occurred in the nonrandomized phase. Trial characteristics and results are summarized in Tables 2 and 3. The trial met its primary efficacy endpoint, with a statistically significant 28% relative reduction in the rate of heart failure-related hospitalizations at 6 months. However, members of the FDA advisory committee in 2011 were unable to distinguish the effect of the device from the effect of nurse communications, and so the FDA denied approval of CardioMEMS and requested additional clarification from the manufacturer.^3, Subsequently, the FDA held a second advisory committee meeting in 2013 to review additional data (including open-access phase) and address previous concerns related to impact of nurse communication on the CHAMPION trial.^9,10,

The 2 major limitations in the early data were related to the potential impact of nurse communication and lack of treatment effect in women.

The sponsor conducted multiple analyses to address the impact of nurse intervention on heart failure-related hospitalizations. These analyses included: (1) independent auditing of all nurse communication to estimate quantitatively the number of hospitalizations that could have been influenced by nurse communication, (2) using a propensity-based score to match patients in the CardioMEMS group who did not receive nurse communications with those in the control base, (3) comparing whether the new knowledge of pulmonary arterial pressure in the former control during the open-access phase led to reductions in heart failure-related hospitalizations, (4) comparing whether the ongoing access to pulmonary artery pressures in the treatment group during the open-access phase was accompanied by continued reduced rates of heart failure hospitalizations, and (5) comparing whether if similar access to pulmonary artery pressures in the former control group and treatment group during the open-access phase was associated with similar rates of heart failure-related hospitalizations.^9, The FDA concluded that all such analyses had methodologic limitations. Propensity matching cannot balance unmeasured characteristics and confounders, and therefore conclusions drawn from propensity analysis were not definitive.^3,While the FDA concluded that the third-party audit of nurse communication was valid, it was difficult to estimate accurately how many heart failure-related hospitalizations were avoided by the nurse communications. The FDA stated that the longitudinal analyses (see points 3 to 5 above) were the most useful regarding supporting device effectiveness. Therefore, only data from analyses 3 to 5 are summarized in Table 4 and discussed next. It is important to acknowledge that all such analyses were post hoc and were conducted with the intent to test the robustness of potentially biased RCT results; therefore, results from these analyses should be evaluated to assess consistency and not as an independent source of evidence to support efficacy. As indicated in Table 4, the longitudinal analyses of individual patient data showed that the device appears to be associated with reducing heart failure-related hospitalization rate. However, there are important trial limitations, notably, subject dropouts were not random, and patient risk profiles could have changed from the randomized phase to the open-access phase. In the open-access phase, 93 (34%) of 270 subjects in the treatment group and 110 (39%) of 280 subjects in the control group remained in the analysis.

According to the FDA documents, the apparent lack of reduction in heart failure-related hospitalization in women resulted from a greater number of deaths among women in the control group early in the trial, and this early mortality resulted in a competing risk for future heart failure hospitalizations. While both the FDA and sponsor conducted multiple analyses to understand device effectiveness in women, the FDA statisticians concluded that such analyses did clearly delineate the limited treatment effect in women.^9, The effectiveness of CardioMEMS in women may be clarified when results of a postmarketing study, currently ongoing and proposed to enroll at least 35% (n=420) women of the enrollment (n=1200), are published.

Other subgroup analysis of CHAMPION trial in patients with reduced ejection fraction,^11, preserved ejection fraction,^12, Medicare-eligible patients,^13, and chronic obstructive pulmonary disease^14, are out of scope and not discussed in this policy.

Table 2. Summary of Key RCT Characteristics

Author; Trial	Countries	Sites	Dates	Participants	Interventions
					Active	Comparator
Abraham et al (2011, 2016)7,8,; CHAMPION	U.S.	64	2007-2009	At least 1 previous HFH in the past 12 mo and NYHA class III HF for at least 3 mo 40% patients from academic setting and 60% from community setting	Disease management by daily measurement of pulmonary artery pressures (via CardioMEMS) plus standard of care (n=270)	Disease management by standard of care alone (n=280)

HF: heart failure; HFH: heart failure hospitalization; NYHA: New York Heart Association; RCT: randomized controlled trial.

Table 3. Summary of Key RCT Results

Trial	HFH, n (events per patient)		Device- or System-Related Complications, n (%)		Pressure-Sensor Failures at 6 or 12 Months
	At 6 Months	At 12 Months	At 6 Months	At 12 Months
Abraham et al (2011, 2016)7,8,; CHAMPION	550	550	550	550	550
CardioMEMS	84 (0.32)	182 (0.46)	3 (1)	0	0
Control	120 (0.44)	279 (0.68)	3 (1)	0	0
HR (95% CI)	0.72 (0.60 to 0.85)	0.67 (0.55 to 0.80)	NA	NA	NA
NNT (95% CI)	8 (not reported)	4 (not reported)	NA	NA	NA

CI: confidence interval; HFH: heart failure hospitalization; HR: hazard ratio; NA: not applicable; NNT: number needed to treat; RCT: randomized controlled trial.

Table 4. Summary of Additional Analyses of the CHAMPION RCT

Trial Period	Randomized Group	CardioMEMS Data Available	Nurse Communications	Comparison	HR for HFH (95% CI)
Randomized access	Treatment	Yes	Yes	Former control to control	0.52 (0.40 to 0.69)
	Control	No	No	Former treatment to treatment	0.93 (0.70 to 1.22)
Open access	Former control	Yes	No	Former control to former treatment	0.80 (0.56 to 1.14)
	Former treatment	Yes	No	NR	NR

Adapted from Abraham et al (2016) and FDA (2013).^10,9,
CI: confidence interval; HFH: heart failure hospitalization; HR: hazard ratio; NR: not reported.

The purpose of the limitations tables (see Tables 5 and 6) is to display notable limitations identified in each study. This information is synthesized as a summary of the body of evidence following each table and provides the conclusions on the sufficiency of evidence supporting the position statement.

Table 5. Study Relevance Limitations

Trial	Populationa	Interventionb	Comparatorc	Outcomesd	Follow-Upe
Abraham et al(2011, 2016)7,8,; CHAMPION		1. Delivery not similar intensity as comparator. Treatment group received additional nurse communication for enhanced protocol compliance. Trial intention was to assess physician's ability to use PA pressure information and not capabilities of sponsor's nursing staff to monitor and correct physician-directed therapy.

The study limitations stated in this table are those notable in the current review; this is not a comprehensive limitations assessment.
PA: pulmonary artery.

^a Population key: 1. Intended use population unclear; 2. Clinical context is unclear; 3. Study population is unclear; 4. Study population not representative of intended use.
^b Intervention key: 1. Not clearly defined; 2. Version used unclear; 3. Delivery not similar intensity as comparator; 4. Not the intervention of interest.
^c Comparator key: 1. Not clearly defined; 2. Not standard or optimal; 3. Delivery not similar intensity as intervention; 4. Not delivered effectively.
^d Outcomes key: 1. Key health outcomes not addressed; 2. Physiologic measures, not validated surrogates; 3. No CONSORT reporting of harms; 4. Not establish and validated measurements; 5. Clinical significant difference not prespecified; 6. Clinical significant difference not supported.
^e Follow-Up key: 1. Not sufficient duration for benefit; 2. Not sufficient duration for harms.

Trial	Allocationa	Blindingb	Selective Reportingc	Follow-Up	Powere	Statisticalf
Abraham (2011, 2016)7,8,; CHAMPION		1. Physicians not blinded to treatment assignment but outcome assessment was independent and blinded

^a Allocation key: 1. Participants not randomly allocated; 2. Allocation not concealed; 3. Allocation concealment unclear; 4. Inadequate control for selection bias.
^b Blinding key: 1. Not blinded to treatment assignment; 2. Not blinded outcome assessment; 3. Outcome assessed by treating physician.
^c Selective Reporting key: 1. Not registered; 2. Evidence of selective reporting; 3. Evidence of selective publication.
^d Follow-Up key: 1. High loss to follow-up or missing data; 2. Inadequate handling of missing data; 3. High number of crossovers; 4. Inadequate handling of crossovers; 5. Inappropriate exclusions; 6. Not intent to treat analysis (per protocol for noninferiority trials).
^e Power key: 1. Power calculations not reported; 2. Power not calculated for primary outcome; 3. Power not based on clinically important difference.
^f Statistical key: 1. Intervention is not appropriate for outcome type: (a) continuous; (b) binary; (c) time to event; 2. Intervention is not appropriate for multiple observations per patient; 3. Confidence intervals and/or p values not reported; 4. Comparative treatment effects not calculated.

As previously described in the selection criteria, studies will be included here to assess long-term outcomes and adverse effects if they capture longer periods of follow-up and/or larger populations than the RCTs.

Desai et al (2017) published a retrospective cohort study of Medicare administrative claims data for individuals who received the CardioMEMS device following the FDA approval.^15, Of 1935 Medicare enrollees who underwent implantation of the device, 1114 were continuously enrolled and had evaluable data for at least 6 months before, and following, implantation. A subset of 480 enrollees had complete data for 12 months before and after implantation. Study characteristics and results are summarized in Tables 7 and 8. The cumulative incidence of heart failure-related hospitalizations were significantly lower in the postimplantation period than in the preimplantation period at both 6- and 12-month follow-ups. Limitations of this pre-post retrospective study include lack of data on medical history, ejection fraction, indication for implantation and possible confounding due to amplified touchpoints with the health care system necessitated by the device's implantation.

Vaduganathan (2017) analyzed mandatory and voluntary reports of device-related malfunctions reported to the FDA to identify CardioMEMS HF System-related adverse events within the first 3 years of the FDA approval.^16, From among the more than 5500 CardioMEMS implants in the first 3 years, there were 155 adverse event reports covering 177 distinct adverse events for a rate of 2.8%. There were 28 reports of pulmonary artery injury/hemoptysis (0.5%) that included 14 intensive care unit stays, 7 intubations, and 6 deaths. Sensor failure, malfunction, or migration occurred in 46 cases, of which 35 required recalibrations. Compared with a reported 2.8% event rate, the serious adverse event rate in CHAMPION trial was 2.6% with 575 implant attempts, including 1 case of pulmonary artery injury and 2 deaths. Limitation of the current analysis primarily included lack of adjudication and limited clinical data.

Table 7. Summary of Key Nonrandomized Study Characteristics

Author	Study Type	Country/Institution	Dates	Participants	Treatment	Follow-Up
Desai et al (2017)15,	Retrospective cohort	U.S./Medicare	2014-2015	Individuals with inpatient CPT codes consistent with use of procedure	CardioMEMS implant	2 cohorts: 6-mo preimplant and postimplant data (n=1114) 12-mo preimplant and postimplant data (n=480)
Vaduganathan et al (2017)16,	Postmarketing surveillance study	U.S./FDA and Abbott	2014-2017	Individuals reporting Cardio-MEMS-related adverse event	CardioMEMS implant	Not applicable

FDA: U.S. Food and Drug Administration.

Table 8. Summary of Key Nonrandomized Study Results

Study	HFH at 6 Months	HFH at 12 Months	Safety
Desai et al (2017)15,	1114	480	NR
Preimplant, n	1020	696	NR
Postimplant, n	381	300	NR
HR (95% CI); p	0.55 (0.49 to 0.61); <.001	0.66 (0.57 to 0.76); <.001	NR
Vaduganathan et al (2017)16,			Estimated 5500 received CardioMEMS
AE cohort identified from MAUDE database	NR	NR	155 (2.8%) AEs; 28 pulmonary artery injury or hemoptysis (0.5%), and 2 (0.4%) deaths

AE: adverse event; CI: confidence interval; HFH: heart failure hospitalization; HR: hazard ratio; NR: not reported.

Case Series

Heywood et al (2017) reported pulmonary artery pressure data for the first 2000 consecutive patients with at least 6 months of follow-up who were implanted with CardioMEMS. No clinical data were reported except for pulmonary artery measurement.^17, Study characteristics and results are summarized in Tables 9 and 10. The mean age of the cohort enrolled was 70 years and the mean follow-up period was 333 days. There was a median of 1.2 days between remote pressure transmissions and greater than 98% weekly use of the system, demonstrating a high level of adherence.

Table 9. Summary of Key Case Series Characteristics

Author	Country/Institution	Participants	Treatment Delivery	Follow-Up (SD)
Heywood et al (2017)17,	U.S./Abbott	First 2000 individuals who received CardioMEMS with follow-up data for a minimum of 6 mo	CardioMEMS	333 (125) d

SD: standard deviation.

Table 10. Summary of Key Case Series Results

Author	Treatment	AUC (mm Hg day)	Adherence
Heywood et al (2017)17,	CardioMEMS device	-32.8 mm Hg/d (1 mo) -156.2 mm Hg/d (3 mo) -434.0 mm Hg/d (6 mo)	Median days between transmissions: 1.07 d (first 30 d) and 1.27 days (after 6 mo) Use of the system: 98.6% (IQR, 82.9%-100.0%)

AUC: area under the curve; IQR: interquartile range.

Section Summary: Implantable Pulmonary Artery Pressure Monitoring (CardioMEMS Device)

The pivotal CHAMPION RCT reported a statistically significant decrease in heart failure-related hospitalizations in patients implanted with CardioMEMS device compared with usual care. However, trial results were potentially biased in favor of the treatment group due to use of additional nurse communication to enhance protocol compliance with the device. The trial intended to assess the physician's ability to use pulmonary artery pressure information and not the capabilities of the sponsor's nursing staff to monitor and correct physician-directed therapy. The manufacturer conducted multiple analyses to address the potential bias from the nurse interventions. These analyses were reviewed favorably by the FDA. While these analyses demonstrated the consistency of benefit from the CardioMEMS device, all such analyses have methodologic limitations. With greater adoption of this technology, it is likely to be used by a broader group of clinicians with variable training in the actual procedure and used in patients at a higher risk compared with those in the CHAMPION trial. Early safety data have been suggestive of a higher rate of procedural complications, particularly related to pulmonary artery injury. Given that the intervention is invasive and intended to be used for a highly prevalent condition, in the light of limited safety data, lack of demonstrable mortality benefit, and pending questions related to its benefit for reduction in hospitalization, the net benefit remains uncertain. Many concerns may be clarified by an ongoing postmarketing study that proposes to enroll 1200 patients (at least 35% women) is reported.

Noninvasive Thoracic Bioimpedance/Impedance Cardiography
Clinical Context and Test Purpose

The purpose of thoracic bioimpedance in patients who have heart failure in an outpatient setting is (1) to guide volume management, (2) to identify physiologic changes that precede clinical symptoms and thus allow preventive interventions, and (3) to prevent hospitalizations.

The question addressed in this policy is: Does the use of thoracic bioimpedance/impedance cardiography improve net health outcomes in individuals with heart failure in the outpatient setting?

The following PICO was used to select literature to inform this policy.

Patients

The relevant population of interest is patients with chronic heart failure who are at risk of developing acute decompensated heart failure (ADHF).

Interventions

The test being considered is thoracic bioimpedance.

Bioimpedance is defined as the electrical resistance of current flow through tissue. For example, when small electrical signals are transmitted through the thorax, the current travels along the blood-filled aorta, which is the most conductive area. Changes in bioimpedance, measured during each beat of the heart, are inversely related to pulsatile changes in volume and velocity of blood in the aorta. Cardiac output is the product of stroke volume by heart rate and, thus, can be calculated from bioimpedance. Cardiac output is generally reduced in patients with systolic heart failure. Acute decompensation is characterized by worsening of cardiac output from the patient's baseline status. The technique is alternatively known as impedance cardiography.

This noninvasive procedure is administered by a cardiologist in an outpatient clinical setting.

Comparators

The comparator of interest is standard clinical care without testing. Decisions on guiding volume management are being made based on signs and symptoms.

Patients with heart failure are managed by cardiologists in an outpatient clinical setting.

Outcomes

The general outcomes of interest are the prevention of decompensation episodes, reductions in hospitalization and mortality, and improvements in quality of life.

Generally, demonstration of outcomes over a 1-year period is meaningful for interventions.

Review of Evidence
Technically Reliable

Assessment of technical reliability focuses on specific tests and operators and requires review of unpublished and often proprietary information. Review of specific tests, operators, and unpublished data are outside the scope of this policy, and alternative sources exist. This policy focuses on the clinical validity and clinical utility.

Clinically Valid

A test must detect the presence or absence of a condition, the risk of developing a condition in the future, or treatment response (beneficial or adverse).

Several studies were excluded from the evaluation of the clinical validity of the thoracic bioimpedance testing because they did not include information needed to assess clinical validity.^18,19,20,

Packer et al (2006) reported on use of impedance cardiography measured by BioZ impedance cardiography monitor to predict decompensation in patients with chronic heart failure.^21, In this study, 212 stable patients with heart failure and a recent episode of decompensation underwent serial evaluation and blinded impedance cardiography testing every 2 weeks for 26 weeks and were followed for the occurrence of death or worsening heart failure requiring hospitalization or emergent care. Results are summarized in Table 11. A composite score of 3 impedance cardiography parameters was a predictor of an event during the next 14 days (p<.001).

Table 11. Clinical Validity of 3-Level Risk Score for BioZ Impedance Cardiography Monitor

Author	Initial N	Final N	Excluded Samples	Prevalence of Condition	Clinical Validity:Mean Probability of Outcome (95% CI), %
					Low Risk	Medium Risk	High Risk
Packer et al (2006)21,	212	212	None	59 patients had 104 episodes of decompensated HF including 16 deaths, 78 hospitalizations, 10 ED visits	1.0 (0.5 to 1.9)	3.5 (2.4 to 4.8)	8.4 (5.8 to 11.6)

CI: confidence interval; ED: emergency department; HF: heart failure.

Section Summary: Clinically Valid

The clinical validity of using thoracic bioimpedance for patients with chronic heart failure who are at risk of developing ADHF has not been established. Association studies are insufficient evidence to determine whether thoracic bioimpedance can improve outcomes in patients with chronic heart failure who are at risk of developing ADHF. There are no studies reporting the clinical validity regarding sensitivity, specificity, or predictive value.

Clinically Useful

A test is clinically useful if the use of the results informs management decisions that improve the net health outcome of care. The net health outcome can be improved if patients receive correct therapy, or more effective therapy, or avoid unnecessary therapy, or avoid unnecessary testing.

Direct Evidence

Direct evidence of clinical utility is provided by studies that have compared health outcomes for patients managed with and without the test. Because these are intervention studies, the preferred evidence would be from RCTs.

Amir et al (2017) reported on results of a prospective study in which 59 patients recently hospitalized for heart failure were selected for ReDS-guided treatment for 90 days.^22, The number of heart failure hospitalizations during 90-day ReDS-guided therapy were compared with hospitalizations in the preceding 90 days before enrollment and the 90 days following discontinuation of ReDS monitoring. During treatment, patients were equipped with the ReDS wearable vest, which was worn once a day at home to measure lung fluid content. Study characteristics and results are summarized in Tables 12 and 13. The rate of heart failure hospitalizations was lower during the ReDS-guided follow-up compared with pre and posttreatment periods. Interpretation of results is uncertain due to the lack of concurrent control and randomization, short-term follow-up, large CIs, and lack of clarity about lost-to-follow-up during the post-ReDS period. An RCT comparing ReDS monitoring with standard of care (SMILE; NCT02448342) was initiated but terminated before its completion.

Table 12. Summary of Key Nonrandomized Study Characteristics

Author	Study Type	Country	Dates	Participants	Treatment	Mean FU (SD), d
Amir et al (2017)22,	Pre-post prospective cohort	Israel	2012-2015	Patients ≥18 y with stage C heart failure, regardless of LVEF (n=59)	ReDS Wearable System	83.0 (25.4)

FU: follow-up; LVEF: left ventricular ejection fraction; SD: standard deviation.

Table 13. Summary of Key Nonrandomized Study Results

Study	Heart Failure-Related Hospitalizations (events/patient/3 mo)	Deaths
Amir et al (2017)22,	50	50
Pre-90-day period (control)	0.04	0
90-day treatment period	0.30	2
Post-90-day period (control)	0.19	2
Hazard ratio (95% confidence interval); p	0.07 (0.01 to 0.54); 0.01a 0.11 (0.014 to 0.88);.037b

^a Treatment versus pretreatment period;
^b Treatment versus posttreatment period.

Chain of Evidence

Indirect evidence on clinical utility rests on clinical validity. If the evidence is insufficient to demonstrate test performance, no inferences can be made about clinical utility. Because the clinical validity of using thoracic bioimpedance has not been proved, a chain of evidence to support its clinical utility cannot be constructed.

Section Summary: Clinical Utility

The clinical utility of using thoracic bioimpedance for patients with chronic heart failure who are at risk of developing ADHF has not been established. One prospective longitudinal study reported that ReDS-guided management reduced heart failure readmissions in ADHF patients recently discharged from the hospital. However, interpretation of results is uncertain due to the lack of concurrent controls and randomization, short-term follow-up, large CIs, and lack of clarity about lost-to-follow-up during the post-ReDS monitoring period. An RCT comparing ReDS monitoring with standard of care was initiated but terminated before its completion.

Inert Gas Rebreathing
Clinical Context and Test Purpose

The purpose of inert gas breathing in patients who have heart failure in an outpatient setting is (1) to guide volume management, (2) to identify physiologic changes that precede clinical symptoms and thus allow preventive interventions, and (3) to prevent hospitalizations.

The question addressed in this policy is: Does the use of inert gas breathing improve net health outcomes in individuals with heart failure in the outpatient setting?

The following PICO was used to select literature to inform this policy.

Patients

The relevant population of interest is patients with chronic heart failure who are at risk of developing ADHF.

Interventions

The test being considered is inert gas breathing.

Inert gas rebreathing is based on the observation that the absorption and disappearance of a blood-soluble gas are proportional to cardiac blood flow. The patient is asked to breathe and rebreathe from a bag filled with oxygen mixed with a fixed proportion of 2 inert gases, typically nitrous oxide and sulfur hexafluoride. The nitrous oxide is soluble in blood and is therefore absorbed during the blood's passage through the lungs at a rate proportional to the blood flow. The sulfur hexafluoride is insoluble in blood and therefore stays in the gas phase and is used to determine the lung volume from which the soluble gas is removed. These gases and carbon dioxide are measured continuously and simultaneously at the mouthpiece.

This noninvasive procedure is administered by a cardiologist in an outpatient clinical setting.

Comparators

The comparator of interest is standard clinical care without testing. Decisions on guiding volume management are being made based on signs and symptoms.

Patients with heart failure are managed by cardiologists in an outpatient clinical setting.

Outcomes

The general outcomes of interest are the prevention of decompensation episodes, reduction in hospitalization and mortality, and improvement in quality of life.

Trials of using inert gas rebreathing for this population were not found. Generally, demonstration of outcomes over a 1-year period is meaningful for interventions.

Technically Reliable

Assessment of technical reliability focuses on specific tests and operators and requires review of unpublished and often proprietary information. Review of specific tests, operators, and unpublished data are outside the scope of this policy, and alternative sources exist. This policy focuses on the clinical validity and clinical utility.

Clinically Valid

A test must detect the presence or absence of a condition, the risk of developing a condition in the future, or treatment response (beneficial or adverse).

No studies on the clinical validity were identified that would establish how the use of inert gas rebreathing measurements helps detect the likelihood of decompensation.

Section Summary: Clinically Valid

The clinical validity of using inert gas breathing for patients with chronic heart failure who are at risk of developing ADHF has not been established.

Clinically Useful

A test is clinically useful if the use of the results informs management decisions that improve the net health outcome of care. The net health outcome can be improved if patients receive correct therapy or more effective therapy, or avoid unnecessary therapy, or avoid unnecessary testing.

Direct Evidence

Direct evidence of clinical utility is provided by studies that have compared health outcomes for patients managed with and without the test. Because these are intervention studies, the preferred evidence would be from RCTs.

No studies were identified that determined how the use of inert gas rebreathing measurements is associated with changes in patient management or evaluated the effects of this technology on patient outcomes.

Chain of Evidence

Indirect evidence on clinical utility rests on clinical validity. If the evidence is insufficient to demonstrate test performance, no inferences can be made about clinical utility. Because the clinical validity of using inert gas breathing has not been proved, a chain of evidence to support clinical utility cannot be constructed.

Section Summary: Clinically Valid

No studies of clinical utility were identified that determined how the use of inert gas breathing measurements in managing heart failure affects patient outcomes. It is unclear how such devices will improve patient outcomes.

Noninvasive Left Ventricular End-Diastolic Pressure Estimation
Clinical Context and Test Purpose

The purpose of LVEDP estimation in patients who have heart failure in an outpatient setting is (1) to guide volume management, (2) to identify physiologic changes that precede clinical symptoms and thus allow preventive interventions, and (3) to prevent hospitalizations.

The question addressed in this policy is: Does the use of noninvasive LVEDP estimation improve health outcomes in individuals with heart failure in the outpatient setting?

The following PICO was used to select literature to inform this policy.

Patients

The relevant population of interest is patients with chronic heart failure who are at risk of developing ADHF.

Interventions

The test being considered is noninvasive LVEDP estimation.

LVEDP is elevated with acute decompensated heart failure. While direct catheter measurement of LVEDP is possible for patients undergoing cardiac catheterization for diagnostic or therapeutic reasons, its invasive nature precludes outpatient use. Noninvasive measurements of LVEDP have been developed based on the observation that arterial pressure during the strain phase of the Valsalva maneuver may directly reflect the LVEDP. Arterial pressure responses during repeated Valsalva maneuvers can be recorded and analyzed to produce values that correlate to the LVEDP.

This noninvasive procedure is administered by a cardiologist in an outpatient clinical setting.

Comparators

The comparator of interest is standard clinical care without testing. Decisions guiding volume management are being made based on signs and symptoms.

Patients with heart failure are managed by cardiologists in an outpatient clinical setting.

Outcomes

The general outcomes of interest are the prevention of decompensation episodes, reduction in hospitalization and mortality, and improvement in quality of life.

Trials of using noninvasive LVEDP estimation for this population were not found. Generally, demonstration of outcomes over a 1-year period is meaningful for interventions.

Technically Reliable

Assessment of technical reliability focuses on specific tests and operators and requires review of unpublished and often proprietary information. Review of specific tests, operators, and unpublished data are outside the scope of this policy, and alternative sources exist. This policy focuses on the clinical validity and clinical utility.

Clinically Valid

A test must detect the presence or absence of a condition, the risk of developing a condition in the future, or treatment response (beneficial or adverse).

Silber et al (2012) reported on finger photoplethysmography during the Valsalva maneuver performed in 33 patients before cardiac catheterization.^23, LVEDP was measured via a catheter placed in the left ventricle and used as the reference standard. For identifying LVEDP greater than 15 mm Hg, finger photoplethysmography during the Valsalva maneuver was 85% sensitive (95% CI, 54% to 97%) and 80% specific (95% CI, 56% to 93%).

Section Summary: Clinically Valid

Only 1 study was identified assessing the use of LVEDP monitoring in this patient population; it reported an 85% sensitivity and an 80% specificity to detect LVEDP greater than 15 mm Hg.

Clinically Useful

A test is clinically useful if the use of the results informs management decisions that improve the net health outcome of care. The net health outcome can be improved if patients receive correct therapy, or more effective therapy, or avoid unnecessary therapy, or avoid unnecessary testing.

Direct Evidence

Direct evidence of clinical utility is provided by studies that have compared health outcomes for patients managed with and without the test. Because these are intervention studies, the preferred evidence would be from RCTs.

No studies were identified that determined how the use of noninvasive LVEDP estimation is associated with changes in patient management or evaluated the effects on patient outcomes.

Chain of Evidence

Indirect evidence on clinical utility rests on clinical validity. If the evidence is insufficient to demonstrate test performance, no inferences can be made about clinical utility.

Because the clinical validity of using noninvasive LVEDP estimation has only been demonstrated in a small, single study, a chain of evidence to support clinical utility cannot be constructed.

Section Summary: Clinically Useful

No studies of clinical utility were identified that assessed how the use of noninvasive LVEDP estimation in managing heart failure affects patient outcomes. A chain of evidence on the clinical utility of noninvasive LVEDP estimation cannot be constructed because it is unclear how these devices will improve patient outcomes.

Summary of Evidence

For individuals who have heart failure in outpatient settings who receive hemodynamic monitoring with an implantable pulmonary artery pressure sensor device, the evidence includes randomized controlled trials. Relevant outcomes are overall survival, symptoms, functional outcomes, quality of life, morbid events, hospitalizations, and treatment-related morbidity. One implantable pressure monitor, the CardioMEMS device, has U.S. Food and Drug Administration approval. The pivotal CardioMEMS Heart Sensor Allows Monitoring of Pressure to Improve Outcomes in NYHA III Heart Failure Patients randomized controlled trial reported a statistically significant decrease in heart failure-related hospitalizations in patients implanted with CardioMEMS device compared with usual care. However, trial results were potentially biased in favor of the treatment group due to use of additional nurse communication to enhance protocol compliance with the device. The manufacturer conducted multiple analyses to address potential bias from the nurse interventions. Results were reviewed favorably by the Food and Drug Administration. While these analyses demonstrated the consistency of benefit from the CardioMEMS device, all such analyses have methodologic limitations. Early safety data have been suggestive of a higher rate of procedural complications, particularly related to pulmonary artery injury. Given that the intervention is invasive and intended to be used for a highly prevalent condition, in the light of limited safety data, lack of demonstrable mortality benefit, and pending questions related to its benefit in reducing hospitalizations, the net benefit remains uncertain. Many of these concerns may be clarified by an ongoing postmarketing study that proposes to enroll 1200 patients (at least 35% women) is reported. The evidence is insufficient to determine the effects of the technology on health outcomes.

For individuals who have heart failure in outpatient settings who receive hemodynamic monitoring by thoracic bioimpedance, the evidence includes uncontrolled prospective studies and case series. Relevant outcomes are overall survival, symptoms, functional outcomes, quality of life, morbid events, hospitalizations, and treatment-related morbidity. There is a lack of randomized controlled trial evidence evaluating whether the use of these technologies improves health outcomes over standard active management of heart failure patients. The case series have reported physiologic measurement-related outcomes and/or associations between monitoring information and heart failure exacerbations, but do not provide definitive evidence on device efficacy. The evidence is insufficient to determine the effects of the technology on health outcomes.

For individuals who have heart failure in outpatient settings who receive hemodynamic monitoring with inert gas rebreathing, no studies have been identified on clinical validity or clinical utility. Relevant outcomes are overall survival, symptoms, functional outcomes, quality of life, morbid events, hospitalizations, and treatment-related morbidity. The evidence is insufficient to determine the effects of the technology on health outcomes.

For individuals who have heart failure in outpatient settings who receive hemodynamic monitoring of arterial pressure during the Valsalva maneuver, a single study was identified. Relevant outcomes are overall survival, symptoms, functional outcomes, quality of life, morbid events, hospitalizations, and treatment-related morbidity. The study assessed the use of LVEDP monitoring and reported an 85% sensitivity and an 80% specificity to detect LVEDP greater than 15 mm Hg. The evidence is insufficient to determine the effects of the technology on health outcomes.

SUPPLEMENTAL INFORMATION
Practice Guidelines and Position Statements
American College of Cardiology et al

In 2017, the American College of Cardiology, the American Heart Association, and the Heart Failure Society of America issued joint guidelines on the management of heart failure that offered no recommendations for the use of ambulatory monitoring devices.^24,

European Society of Cardiology

The European Society of Cardiology guidelines on the diagnosis and treatment of acute and chronic heart failure stated the following: "Monitoring of pulmonary artery pressures using a wireless implantable hemodynamic monitoring system (CardioMEMS) may be considered in symptomatic patients with HF [heart failure] with previous HF hospitalization in order to reduce the risk of recurrent HF hospitalization" (class IIb, level B recommendation.)^25,

National Institute for Health and Care Excellence

In 2018, the National Institute for Health and Care Excellence (NICE) updated their guidelines on chronic heart failure management and did not include outpatient hemodynamic monitoring as a recommendation. ^26,

In 2013, the Institute issued guidance on the insertion and use of implantable pulmonary artery pressure monitors in chronic heart failure.^27, The recommendations concluded that "Current evidence on the safety and efficacy of the insertion and use of implantable pulmonary artery pressure monitors in chronic heart failure is limited in both quality and quantity."

Heart Failure Society of America

In 2018, the Heart Failure Society of America Scientific Statements Committee (2018) published a white paper consensus statement on remote monitoring of patients with heart failure.^28,

The committee concluded that: "Based on available evidence, routine use of external RPM devices is not recommended. Implanted devices that monitor pulmonary arterial pressure and/or other parameters may be beneficial in selected patients or when used in structured programs, but the value of these devices in routine care requires further study."

U.S. Preventive Services Task Force Recommendations

Not applicable.

Ongoing and Unpublished Clinical Trials

Some currently unpublished trials that might influence this policy are listed in Table 14.

Table 14. Summary of Key Trials

NCT No.	Trial Name	Planned Enrollment	Completion Date
Ongoing
NCT02950597	Evaluation of Clinical Impact of Non-Invasive Hemodynamic Monitoring to Optimize Preventive Care of Heart Failure Patients	197	Nov 2019
NCT02693691	CardioMEMS European Monitoring Study for Heart Failure	239	Dec 2019
NCT02954341	CardioMEMS HF SystemOUS Post Market Study	800	Dec 2023
NCT03387813	Hemodynamic-GUIDEd Management of Heart Failure	3600	Apr 2023
Unpublished
NCT01121107	Left Atrial Pressure Monitoring to Optimize Heart Failure Therapy Study	486	Apr 2015 (updated 02/04/2019)

NCT: national clinical trial.]
________________________________________________________________________________________

Horizon BCBSNJ Medical Policy Development Process:

This Horizon BCBSNJ Medical Policy (the “Medical Policy”) has been developed by Horizon BCBSNJ’s Medical Policy Committee (the “Committee”) consistent with generally accepted standards of medical practice, and reflects Horizon BCBSNJ’s view of the subject health care services, supplies or procedures, and in what circumstances they are deemed to be medically necessary or experimental/ investigational in nature. This Medical Policy also considers whether and to what degree the subject health care services, supplies or procedures are clinically appropriate, in terms of type, frequency, extent, site and duration and if they are considered effective for the illnesses, injuries or diseases discussed. Where relevant, this Medical Policy considers whether the subject health care services, supplies or procedures are being requested primarily for the convenience of the covered person or the health care provider. It may also consider whether the services, supplies or procedures are more costly than an alternative service or sequence of services, supplies or procedures that are at least as likely to produce equivalent therapeutic or diagnostic results as to the diagnosis or treatment of the relevant illness, injury or disease. In reaching its conclusion regarding what it considers to be the generally accepted standards of medical practice, the Committee reviews and considers the following: all credible scientific evidence published in peer-reviewed medical literature generally recognized by the relevant medical community, physician and health care provider specialty society recommendations, the views of physicians and health care providers practicing in relevant clinical areas (including, but not limited to, the prevailing opinion within the appropriate specialty) and any other relevant factor as determined by applicable State and Federal laws and regulations.
___________________________________________________________________________________________________________________________

Index:
Cardiac Hemodynamic Monitoring for the Management of Heart Failure in the Outpatient Setting
Ambulatory Cardiac Hemodynamic Monitoring
Cardiac Output Monitoring by Electrical Bioimpedance
Electrical Bioimpedance, Cardiac Output Monitoring
Heart Failure
Bioimpedance, Thoracic
Impedance Cardiography
Inert Gas Rebreathing
Left Ventricular End Diastolic Pressure, Non-Invasive Measurement
BioZ
Innocor
VeriCor
Endosure
LVEDP, Non-Invasive Measurement
CardioMEMS Champion Heart Failure Monitoring System
CardioMEMS HF

References:
1. Opasich C, Rapezzi C, Lucci D, et al. Precipitating factors and decision-making processes of short-term worsening heart failure despite optimal treatment (from the IN-CHF Registry). Am J Cardiol. Aug 15 2001; 88(4): 382-7. PMID 11545758

2. McAlister FA, Stewart S, Ferrua S, et al. Multidisciplinary strategies for the management of heart failure patients at high risk for admission: a systematic review of randomized trials. J Am Coll Cardiol. Aug 18 2004; 44(4): 810-9. PMID 15312864

3. Food and Drug Administration. Summary of Safety and Effectiveness Data (SSED): CardioMEMS HF System. 2014; https://www.accessdata.fda.gov/cdrh_docs/pdf10/P100045b.pdf. Accessed March 19, 2020.

4. Loh JP, Barbash IM, Waksman R. Overview of the 2011 Food and Drug Administration Circulatory System Devices Panel of the Medical Devices Advisory Committee Meeting on the CardioMEMS Champion Heart Failure Monitoring System. J Am Coll Cardiol. Apr 16 2013; 61(15): 1571-6. PMID 23352783

5. International Consortium for Health Outcomes Measurement, Inc (ICHOM). Heart Failure version 1.1.4. Oct 2017. Accessed March 19, 2020.

6. Zannad F, Garcia AA, Anker SD, et al. Clinical outcome endpoints in heart failure trials: a European Society of Cardiology Heart Failure Association consensus document. Eur J Heart Fail. Oct 2013; 15(10): 1082-94. PMID 23787718

7. Abraham WT, Adamson PB, Bourge RC, et al. Wireless pulmonary artery haemodynamic monitoring in chronic heart failure: a randomised controlled trial. Lancet. Feb 19 2011; 377(9766): 658-66. PMID 21315441

8. Abraham WT, Stevenson LW, Bourge RC, et al. Sustained efficacy of pulmonary artery pressure to guide adjustment of chronic heart failure therapy: complete follow-up results from the CHAMPION randomised trial. Lancet. Jan 30 2016; 387(10017): 453-61. PMID 26560249

9. CardioMEMS ChampionTM HF Monitoring System: FDA Review of P100045/A004FDA Presentation - CardioMEMS: Oct. 9, 2013. 2013; https://wayback.archive- it.org/7993/20170111163259/http://www.fda.gov/downloads/AdvisoryCommittees/CommitteesMeetingMaterials/ MedicalDevices/MedicalDevicesAdvisoryCommittee/CirculatorySystemDevicesPanel/UCM370955.pdf. Accessed March 19, 2020.

10. CardioMEMSChampionTM Heart Failure Monitoring System: Presentation - CardioMEMS: Oct. 9, 2013. 2013; https://wayback.archive- it.org/7993/20170111163201/http://www.fda.gov/downloads/AdvisoryCommittees/CommitteesMeetingMaterials/ MedicalDevices/MedicalDevicesAdvisoryCommittee/CirculatorySystemDevicesPanel/UCM370951.pdf. Accessed March 19, 2020.

11. Givertz MM, Stevenson LW, Costanzo MR, et al. Pulmonary Artery Pressure-Guided Management of Patients With Heart Failure and Reduced Ejection Fraction. J Am Coll Cardiol. Oct 10 2017; 70(15): 1875-1886. PMID 28982501

12. Adamson PB, Abraham WT, Bourge RC, et al. Wireless pulmonary artery pressure monitoring guides management to reduce decompensation in heart failure with preserved ejection fraction. Circ Heart Fail. Nov 2014; 7(6): 935-44. PMID 25286913

13. Adamson PB, Abraham WT, Stevenson LW, et al. Pulmonary Artery Pressure-Guided Heart Failure Management Reduces 30-Day Readmissions. Circ Heart Fail. Jun 2016; 9(6). PMID 27220593

14. Krahnke JS, Abraham WT, Adamson PB, et al. Heart failure and respiratory hospitalizations are reduced in patients with heart failure and chronic obstructive pulmonary disease with the use of an implantable pulmonary artery pressure monitoring device. J Card Fail. Mar 2015; 21(3): 240-9. PMID 25541376

15. Desai AS, Bhimaraj A, Bharmi R, et al. Ambulatory Hemodynamic Monitoring Reduces Heart Failure Hospitalizations in Real-World Clinical Practice. J Am Coll Cardiol. May 16 2017; 69(19): 2357-2365. PMID 28330751

16. Vaduganathan M, DeFilippis EM, Fonarow GC, et al. Postmarketing Adverse Events Related to the CardioMEMS HF System. JAMA Cardiol. Nov 01 2017; 2(11): 1277-1279. PMID 28975249

17. Heywood JT, Jermyn R, Shavelle D, et al. Impact of Practice-Based Management of Pulmonary Artery Pressures in 2000 Patients Implanted With the CardioMEMS Sensor. Circulation. Apr 18 2017; 135(16): 1509-1517. PMID 28219895

18. Kamath SA, Drazner MH, Tasissa G, et al. Correlation of impedance cardiography with invasive hemodynamic measurements in patients with advanced heart failure: the BioImpedance CardioGraphy (BIG) substudy of the Evaluation Study of Congestive Heart Failure and Pulmonary Artery Catheterization Effectiveness (ESCAPE) Trial. Am Heart J. Aug 2009; 158(2): 217-23. PMID 19619697

19. Anand IS, Greenberg BH, Fogoros RN, et al. Design of the Multi-Sensor Monitoring in Congestive Heart Failure (MUSIC) study: prospective trial to assess the utility of continuous wireless physiologic monitoring in heart failure. J Card Fail. Jan 2011; 17(1): 11-6. PMID 21187259

20. Anand IS, Tang WH, Greenberg BH, et al. Design and performance of a multisensor heart failure monitoring algorithm: results from the multisensor monitoring in congestive heart failure (MUSIC) study. J Card Fail. Apr 2012; 18(4): 289-95. PMID 22464769

21. Packer M, Abraham WT, Mehra MR, et al. Utility of impedance cardiography for the identification of short-term risk of clinical decompensation in stable patients with chronic heart failure. J Am Coll Cardiol. Jun 06 2006; 47(11): 2245-52. PMID 16750691

22. Amir O, Ben-Gal T, Weinstein JM, et al. Evaluation of remote dielectric sensing (ReDS) technology-guided therapy for decreasing heart failure re-hospitalizations. Int J Cardiol. Aug 01 2017; 240: 279-284. PMID 28341372

23. Silber HA, Trost JC, Johnston PV, et al. Finger photoplethysmography during the Valsalva maneuver reflects left ventricular filling pressure. Am J Physiol Heart Circ Physiol. May 15 2012; 302(10): H2043-7. PMID 22389389

24. Yancy CW, Jessup M, Bozkurt B, et al. 2017 ACC/AHA/HFSA Focused Update of the 2013 ACCF/AHA Guideline for the Management of Heart Failure: A Report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines and the Heart Failure Society of America. J Am Coll Cardiol. Aug 08 2017; 70(6): 776-803. PMID 28461007

25. Ponikowski P, Voors AA, Anker SD, et al. 2016 ESC Guidelines for the Diagnosis and Treatment of Acute and Chronic Heart Failure. Rev Esp Cardiol (Engl Ed). Dec 2016; 69(12): 1167. PMID 27894487

26. National Institute for Health and Care Excellence (NICE). Chronic heart failure in adults: diagnosis and management; NICE guideline NG106. September 2018. https://www.nice.org.uk/guidance/ng106. Accessed March 19, 2020.

27. National Institute for Health and Care Excellence (NICE). Insertion and use of implantable pulmonary artery pressure monitors in chronic heart failure [IPG463]. 2013; https://www.nice.org.uk/guidance/ipg463. Accessed March 19, 2020.

28. Dickinson MG, Allen LA, Albert NA, et al. Remote Monitoring of Patients With Heart Failure: A White Paper From the Heart Failure Society of America Scientific Statements Committee. J Card Fail. Oct 2018; 24(10): 682-694. PMID 30308242

29. Centers for Medicare & Medicaid Services (CMS). National coverage decision for cardiac output monitoring by thoracic electrical bioimpedance (TEB) (20.16). 2006; http://www.cms.gov/medicare-coverage- database/details/ncd- details.aspx?NCDId=267&ncdver=3&NCAId=82&NcaName=Electrical+Bioimpedance+for+Cardiac+Output+Moni toring&IsPopup=y&bc=AAAAAAAACAAAAA%3D%3D&. Accessed March 19, 2020.

Codes:
(The list of codes is not intended to be all-inclusive and is included below for informational purposes only. Inclusion or exclusion of a procedure, diagnosis, drug or device code(s) does not constitute or imply authorization, certification, approval, offer of coverage or guarantee of payment.)

CPT*

33289
93264
93701
93799