|MP 2.02.15||Wearable Cardioverter-Defibrillators|
|Original Policy Date
|Last Review Status/Date
Reviewed with literature search/1:2015
|Return to Medical Policy Index|
Our medical policies are designed for informational purposes only and are not an authorization, or an explanation of benefits, or a contract. Receipt of benefits is subject to satisfaction of all terms and conditions of the coverage. Medical technology is constantly changing, and we reserve the right to review and update our policies periodically.
Sudden cardiac arrest (SCA) is the most common cause of death in patients with coronary artery disease. The ICD has proven effective in reducing mortality for survivors of SCA and for patients with documented malignant ventricular arrhythmias. More recently, the use of ICDs has been potentially broadened by studies reporting a reduction in mortality for patients at risk for ventricular arrhythmias, such as patients with prior myocardial infarction (MI) and reduced ejection fraction. ICDs consist of implantable leads in the heart that connect to a pulse generator implanted beneath the skin of the chest or abdomen. ICD placement is a minor surgical procedure, with the ICD device placed under the skin on the chest wall and the cardiac leads placed percutaneously. Potential adverse effects of ICD placement are bleeding, infection, pneumothorax, and delivery of unnecessary counter shocks. See Policy No. 7.01.44 for further information on ICDs.
The WCD is an external device that is intended to perform the same tasks as an ICD, without requiring invasive procedures. It consists of a vest that is worn continuously underneath the patient's clothing. Part of this vest is the “electrode belt” that contains the cardiac-monitoring electrodes and the therapy electrodes that deliver a counter shock. The vest is connected to a monitor with a battery pack and alarm module that is worn on the patient’s belt. The monitor contains the electronics that interpret the cardiac rhythm and determines when a counter shock is necessary. The alarm module alerts the patient to certain conditions by lights or voice messages.
The U.S. Food and Drug Administration (FDA) approved the Lifecor WCD® 2000 system via premarket application approval in December 2001 for “adult patients who are at risk for cardiac arrest and are either not candidates for or refuse an implantable defibrillator.” The vest was renamed and is now called the Zoll® LifeVest.® FDA product code: MVK
Use of WCDs for the prevention of sudden cardiac death is considered medically necessary as interim treatment for those who:
- meet the criteria for an implantable cardioverter-defibrillator (see indications in Policy No. 7.01.44); and
- have a temporary contraindication to receiving an ICD, such as a systemic infection, at the current time; and
- have been scheduled for an ICD placement or who had an ICD removed and have been rescheduled for placement of another ICD once the contraindication is treated.
Use of WCDs for the prevention of sudden cardiac death is considered investigational for the following indications when they are the sole indication for a wearable cardioverter-defibrillator:
- Patients in the immediate (ie, less than 40 days) period following an acute myocardial infarction.
- Patients post-CABG [coronary artery bypass graft] surgery
- Patients with newly diagnosed nonischemic cardiomyopathy
- Women with peripartum cardiomyopathy
- High-risk patients awaiting heart transplant
Use of wearable cardioverter-defibrillators is considered investigational for all other indications.
It is uncommon for patients to have a temporary contraindication to ICD placement. The most common reason will be a systemic infection that requires treatment before the ICD can be implanted. The wearable cardioverter-defibrillator should only be used short-term while the temporary contraindication (eg, systemic infection) is being clinically managed. Once treatment is completed, the permanent ICD should be implanted.
In July 2003, HCPCS codes became effective that are specific to this device:
K0606: Automatic external defibrillator, with integrated electrocardiogram analysis, garment type
K0607: Replacement battery for automated external defibrillator, each
K0608: Replacement garment for use with automated external defibrillator, each
K0609: Replacement electrodes for use with automated external defibrillator, each
The following CPT code describes the professional services involved in the initial set-up and programming of this device:
93745 Initial set-up and programming by a physician of wearable cardioverter-defibrillator includes initial programming of system, establishing baseline electronic electrocardiogram, transmission of data to data repository, patient instruction in wearing system and patient reporting of problems or events
In 2009, a new CPT code was introduced to describe interrogation of a wearable cardioverter-defibrillator device:
93292 Interrogation device evaluation (in person) with physician analysis, review and report, includes connection, recording and disconnection per patient encounter; wearable defibrillator system
Code 93292 cannot be reported with code 93745.
BlueCard/National Account Issues
State or federal mandates (e.g., FEP) may dictate that all FDA-approved devices may not be considered investigational and, thus, these devices may be assessed only on the basis of their medical necessity.
This policy was created in 2003 and updated with periodic literature reviews, most recently through November 30, 2014.
The available evidence on the wearable cardioverter defibrillator (WCD) consists of case series describing outcomes from patients using the device. There are no randomized controlled trials (RCTs) of WCD compared with standard care or alternative treatments. RCTs of patients undergoing permanent implantable cardioverter defibrillator (ICD) implantation can provide indirect evidence on the efficacy of the WCD if the indications for a permanent ICD are similar to the potential indications for WCD and if the performance of the WCD has been shown to approximate that of a permanent ICD.
U.S. Food and Drug Administration (FDA)‒labeled indications for the device are adult patients who are at risk for sudden cardiac arrest (SCA) and either are not candidates for or refuse an implantable ICD.(1) Some experts2 have suggested that the indications for a WCD should be broadened to include other populations at high risk for SCA. These potential indications include:
- Bridge to transplantation (ie, the WEARIT population)
- Bridge to implantable device or clinical improvement (ie, the BIROAD population)
- Post bypass with ejection fraction (EF) less than 30%
- Post bypass with ventricular arrhythmias or syncope within 48 hours of surgery
- Post myocardial infarction with EF less than 30%
- Post myocardial infarction with ventricular arrhythmias within 48 hours
- Drug-related arrhythmias (during drug washout or after, during evaluation of long-term risk)
- Patients awaiting revascularization
- Patients too ill to undergo device implantation
- Patients who refuse device therapy
WCD Effectiveness Compared With an Implantable Device
Is the WCD Effective in Detecting and Terminating Ventricular Arrhythmias for High-Risk Patients, Compared With an Implantable Device?
There are very few peer-reviewed published studies that report on clinical outcomes of WCDs and no studies that evaluate the efficacy of WCD in reducing mortality compared with alternatives. Despite the small amount of evidence, a TEC Assessment completed in 20103 concluded that the evidence is sufficient to conclude that the WCD can successfully terminate malignant ventricular arrhythmias. First, there is strong physiologic rationale for the device. It is known that sensor leads placed on the skin can successfully detect and characterize arrhythmias. It is also established that a successful countershock can be delivered externally. The use of external defibrillators is extensive, ranging from in-hospital use to public placement and use at home. The novelty of this device is in the way that it is packaged and utilized.
Second, there is a small amount of evidence that supports that the device successfully terminates arrhythmias. Two uncontrolled studies were identified that directly tested the efficacy of the WCD. The first4 was a small case series of 15 patients who were survivors of SCA and scheduled to receive an ICD. During the procedure to implant a permanent ICD, or to test a previously inserted ICD, patients wore the WCD while clinicians attempted to induce ventricular arrhythmias. Of the 15 patients, 10 developed ventricular tachycardia (VT) or ventricular fibrillation (VF). The WCD correctly detected the arrhythmia in 9 of 10 cases and successfully terminated the arrhythmia in all 9 cases. In 2010, Chung et al published an evaluation of WCD effectiveness for preventing sudden death based on a postmarket release registry of 3569 patients who received a WCD.(5) Investigators found an overall successful shock rate of 99% for VTor VF (79/80 cases of VT or VF among 59 patients). Fifty-two percent of patients wore the device for more than 90% of the day. Eight patients died after successful conversion of VT/VF.
In 2013, Tanawuttiwat et al reported the results of a retrospective, uncontrolled evaluation of 97 patients who received a WCD after their ICD was explanted due to device infection.(6) Subjects wore the device for a median of 21 days; during the study period, 2 patients had 4 episodes of arrhythmia that were appropriately terminated by the WCD, 1 patient experienced 2 inappropriate treatments, and 3 patients experienced sudden death outside the hospital while not wearing their WCD device.
The WEARIT/BIROAD study7 was a prospective cohort study that evaluated 289 patients at high risk for sudden cardiac death (SCD) but who did not meet criteria for an ICD or who could not receive an ICD for several months. A total of 289 patients were enrolled and followed for a mean of 3.1 months. During this time, there were 8 documented episodes of arrhythmia requiring shock in 6 separate patients. Six of the 8 episodes were successfully resuscitated by the WCD. By group sequential analysis, the estimate of percent successful resuscitations was 69%. There was 99% confidence that the true rate of success was greater than 25% and 90% confidence that the true rate was greater than 44%. In the 2 cases of unsuccessful defibrillation, the authors reported that the WCD was placed incorrectly, with the therapy electrodes reversed and not directed to the skin. Clinical outcomes for longer term follow up for 758 patients prescribed a WCD for a transient or undefined arrhythmia risk who were prospectively enrolled in a registry have been published in abstract form.(8) This abstract reports that during the follow-up period, there were 15 “appropriate” shocks delivered. Details about the registry population, the patient selection process, and the outcomes are not sufficient to allow more complete evaluation of the study findings.
The WEARIT/BIROAD results underscore the difficulty in proper use and compliance with the device. Six patients suffered SCA that was likely due to wearing the device improperly or not wearing the device at all. This implied that a relatively high rate of nonadherence may be the main factor limiting the effectiveness of the WCD. Also, there was a fairly high rate of dropout (22%) over the approximately 3 months of follow-up. In a study of 134 consecutive, uninsured patients with cardiomyopathy and a mean EF of 22.5% (7.3%), Mitrani et al, reported noncompliance with a WCD was even greater. The dropout rate was 35%.(9) The WCD was never used by 8 patients, and only 27% wore the device for more than 90% of the day. Patients who were followed for 72 (55) days wore the WCD for a mean of 14.1 (8.1) hours per day. Additionally, during follow-up, no arrhythmias or shock were detected. In a prospective registry of 82 heart failure patients eligible for WCDs, Kao et al reported 13 patients (15.9%) did not wear the WCD due to refusal, discomfort, or other/unknown reasons.(10) These results suggest that the WCD is likely to be inferior to an ICD, due to suboptimal adherence and difficulty with correct placement of the device. Therefore, these data corroborate the assumption that the WCD should not be used as a replacement for an ICD but only considered in those situations in which the patient does not meet criteria for a permanent ICD.
There are no studies that directly compare the performance of a WCD with a permanent ICD. One small study in the electrophysiology lab demonstrated that the WCD can correctly identify and terminate most induced ventricular arrhythmias. A cohort study of WCD use estimated that the percent of successful resuscitations was approximately 70%. In that study, there was a high rate of nonadherence and dropouts, and failures to successfully resuscitate were largely attributed to incorrect use of the device
and/or nonadherence. Other studies have also reported high rates of nonadherence. This evidence indicates that the WCD can successfully detect and terminate arrhythmias in at least some patients but that the overall performance in clinical care is likely to be inferior to a permanent ICD.
WCD as Bridge to ICD or Recovery
Does the WCD Improve Outcomes When Used as a Bridge to Permanent ICD Placement or Clinical Improvement in the Following Situations, Compared With Usual Care?
- Temporary contraindications to ICD
- Immediate post-MI period
- High-risk patients post-CABG [coronary artery bypass graft] surgery
- High-risk patients awaiting heart transplantation
- Newly diagnosed nonischemic cardiomyopathy
- Peripartum cardiomyopathy
Temporary Contraindications to ICD
Contraindications to an ICD are few. According to the American College of Cardiology/American Heart Association guidelines on ICD use, the device is contraindicated in patients with terminal illness, with drug-refractory class IV heart failure, who are not candidates for transplantation, and in patients with a history of psychiatric disorders that interfere with the necessary care and follow-up postimplantation.(11) It is not known how many patients refuse an ICD after it has been recommended for them.
There is a small number of patients who meet established criteria for an ICD (see Policy No. 7.01.44) but have a transient (ie, short-term) contraindication for an implantable device. The most common contraindication is an infectious process that precludes insertion or when an ICD is removed due to infection, and there must be a delay before reinsertion to treat the infection. The WCD may have benefit in this group, if the device is able to successfully detect and abort ventricular arrhythmias in this
population. The study by Tanawuttiwat et al previously referenced provides some direct evidence that the WCD can be successful, but its successful use may be limited by nonadherence, given that 3 of the 97 patients included in the study died outside of the hospital while not wearing the WCD.
The WCD avoids potential complications associated with ICD implantation, but complication rates with current techniques for ICD placement are low. In 1 large trial of ICD versus antiarrhythmic drug therapy,(12) complications of ICD implantation in 507 patients included hematomas in 13 (2.6%), bleeding requiring transfusion or reoperation in 6 (1.2%), infection in 10 (2.0%), pneumothorax in 8 (1.6%), and cardiac perforation in 1 (0.2%). Early mortality (within 30 days of procedure) was not higher for the ICD group (2.4%), compared with the medication group (3.5%).
Immediate Post-MI Period
The evidence on the use of a WCD as a bridge to permanent ICD placement was reviewed in a 2010 TEC Assessment.(3) The most common of these indications is for patients who are in the immediate postmyocardial infarction (MI) period. For these patients, indications for a permanent ICD cannot be reliably assessed immediately post-MI because it is not possible to determine the final EF until at least 30 days after the event. Because the first 30 days following an acute MI represent a high-risk period for lethal ventricular arrhythmias, there is a potential to improve mortality by using other treatments to prevent SCA.
Despite the rationale for this potential indication, the TEC Assessment concluded that the available evidence does not support the contention that any cardioverter defibrillator improves mortality in patients in the immediate post-MI period. One post hoc analysis of an RCT and 2 prospective RCTs was reviewed that led to this conclusion.
Secondary analysis of data from the MADIT-II trial evaluated whether an ICD improves mortality in the early post-MI period.(13) MADIT-II randomly assigned 1159 patients with prior MI and an EF of less than 30% to an ICD or control and showed an overall mortality benefit for patients treated with an ICD. The secondary analysis examined the benefit of ICD according to length of time from the original MI and showed that the benefit of ICD was dependent on the length of time since the original MI. Within the first 18 months post-MI, there was no benefit found for ICD implantation (hazard ratio [HR], 0.97; 95% confidence interval [CI], 0.51 to 1.81; p=0.92). In contrast, there was a significant mortality benefit when the length of time since MI was greater than 18 months (HR=0.55; 95% CI, 0.39 to 0.78; p=0.001).
Two RCTs were specifically designed to address the question of early ICD use post-MI. The DINAMIT study14 evaluated the utility of an automatic ICD (AICD) for this patient population. This trial randomly assigned 342 patients with an acute MI and an EF of 35% or less. The primary outcome was death from any cause, and a predefined secondary outcome was death from an arrhythmia. After a mean follow-up of 30 months, there was no difference in overall survival for the ICD group compared with control (HR=1.08; 95% CI, 0.76 to 1.55; p=0.66). There was a significant difference for the ICD group in the secondary outcome of death from arrhythmia (HR=0.42; 95% CI, 0.22 to 0.83; p=0.009). The decrease in deaths from arrhythmias for the ICD group was offset by a corresponding increase in deaths due to nonarrhythmic cardiac causes. The authors suggest that the discrepancy in these outcomes may arise from the fact that patients in whom the ICD successfully aborted an arrhythmia may have eventually died from other cardiac causes, such as progressive heart failure.
The IRIS trial(15) was similar in design to the DINAMIT trial. This study included 998 patients who were 5 to 31 days post-MI and had at least 1 other high-risk factor, either nonsustained ventricular tachycardia or a resting pulse greater than 90. Patients were followed for a mean of 37 months. Results of the IRIS trial were similar to DINAMIT, with no difference in overall mortality between the ICD and control groups (26.1% vs 25.8%, respectively, p=0.76). The ICD group had a decreased rate of SCD (6.1% vs 13.2%, respectively, p=0.049), which was offset by a higher rate of non-SCD (15.3% vs 8.6%, respectively, p=0.001). This study also reported noncardiac death, which was similar for the ICD and control groups (4.7% vs 4.0%, respectively, p=0.51).
In 2013, Epstein et al reported on registry data from 8453 post-MI patients who received WCDs for risk of SCA while awaiting placement of an ICD.(16) The WCD was worn a median length of 57 days (mean, 69  days) with a median daily use of 21.8 hours. Appropriate shocks were delivered 309 times in 133 patients (1.6%), 91% of which were successful in resuscitating patients from ventricular arrhythmias. For shocked patients, 62% were revascularized post-MI and the left-ventricular ejection fraction (LVEF) averaged 23.8% (8.8%). While 1.4% of this registry population was successfully treated with WCDs, interpretation of registry data is limited. It is not possible to determine whether outcomes were improved without a control group, and the registry contained limited patient and medical information further limiting interpretation of results.
In 2014, Uyei et al reported results of a systematic review conducted with the goal of evaluating the effectiveness of WCD use in several clinical situations, including for individuals early (≤40 days) post-MI with an LVEF of 35% or less.(17) The authors identified 36 articles and conference abstracts, most of which (n=28 [78%]) were conference abstracts. Four studies (Chung et al ,(5) Epstein et al ,(16) and 2 conference abstracts) assessed the effectiveness of WCD use in post-MI patients. Outcomes reported were heterogeneous. For 2 studies that reported VF/VT-related mortality, on average 0.52% (2/384) of the study population died of VF or VT over 58.3 mean days of WCD use. For 2 studies that reported on VT/VF incidence, on average 2.8% (11/384) of WCD users experienced a VT and/or VF event over the course 58.3 (range, 3-146) mean days of WD use. Among those who experienced a VT/VF event, on average 82% (9/11) experienced successful termination of 1 or more arrhythmic events.
High-Risk Patients After Coronary Revascularization
One RCT (CABG PATCH)(18) evaluated early ICD placement in high-risk post CABG patients, selected by a low LVEF and abnormalities on signal-averaged electrocardiogram. The trial followed patients for a mean of 32 months and reported on overall mortality. Results of this trial indicated no difference in overall mortality between the ICD and control groups (HR=1.07; 95% CI, 0.81 to 1.42). There were no other mortality outcomes reported. There was a higher rate of infections in the ICD group, both deep sternal infections (2.7 vs 0.4%, respectively, p<0.05) and superficial wound infections (12.3 vs 5.9%, respectively, p<0.05). The cumulative incidence of inappropriate shocks was 50% at 1 year and 57% at 2 years.
Zishiri et al performed a retrospective study that used registry data to compare outcomes with or without WCD use in patients with LVEF less than 35% after CABG surgery or percutaneous coronary intervention (PCI).(19) A national registry maintained by the manufacturer was used to identify 809 patients treated with a WCD postdischarge, and a separate registry from the Cleveland Clinic was used to identify 4149 patients discharged without a defibrillator. At baseline, there were significant differences between groups on age, sex, LVEF, and time period of treatment. Of the 809 patients treated with WCD, 1.3% had documented appropriate defibrillation treatment for an arrhythmia. Post-CABG, 90-day mortality was 3% in patients with WCDs versus 7% without WCDs (p=0.03). Post-PCI, 90-day mortality was 2% in patients with WCDs versus 10% without WCDs (p<0.001). Adjusted long-term mortality risks, after a mean followup of 3.2 years, was also decreased in the WCD group (HR=0.74; 95% CI, 0.57 to 0.97; p=0.027). These differences in mortality persisted after propensity matching. However, interpretation of this registry data is limited because patients treated with a WCD differed from patients who were not treated, and these differences may not have been completely eliminated through propensity matching. Therefore, this evidence is not sufficient to determine whether WCDs improve outcomes post coronary revascularization.
In the 2014 Uyei et al systematic review previously described, 3 studies (Chung et al ,(5) Epstein et al ,(16) 1 conference abstract) were identified that reported outcomes for WCDs after coronary revascularization for patients with LVEF of 35% or less.(17) Reported outcomes were heterogeneous across studies. In 1 study that reported on VT/VF-related mortality, 0.41% (1/243) of the study population died of VT or VF over the course of 59.8 days (mean or median not specified). Of those who experienced a VT/VF event, 7% of patients died over the course of “approximately 2 months” of WCD use. In another study, 50% of those with VT/VF events died over the course of 59.8 days.
High-Risk Patients Awaiting Heart Transplantation
There are no studies that specifically address this population of patients, but some patients awaiting transplantation have been included in studies with mixed populations. The WEARIT/BIROAD study, discussed previously, was a prospective cohort study that included patients awaiting transplant, but it also included other high-risk patients and did not report separately on the population of patients awaiting transplant.(7) Rao et al(20) published a case series of 162 patients with either congenital structural heart disease or inherited arrhythmias treated with WCD. Approximately one-third of these patients had a permanent ICD, which was explanted due to infection or malfunction. The remaining patients used the WCD either as a bridge to heart transplantation, during an ongoing cardiac evaluation, or in the setting of surgical or invasive procedures that increased the risk of arrhythmias. There were 4 patient deaths during a mean duration of WCD treatment of approximately 1 month, but none of these were related to cardiac causes. Two patients received a total of 3 appropriate shocks for VT/VF, and 4 patients received a total of 7 inappropriate shocks. The results of this study suggest that the WCD can be worn safely and can detect arrhythmias in this population, but the rate of inappropriate shocks is relatively high.
Newly Diagnosed Nonischemic Cardiomyopathy
Another potential indication for the WCD is in patients with newly diagnosed nonischemic cardiomyopathy. Similar to acute MI, in these patients the final EF is uncertain because some patients who are newly diagnosed with nonischemic cardiomyopathy show an improvement in EF over the ensuing several months. A post hoc analysis of the DEFINITE trial,(21) which evaluated the use of an ICD in nonischemic dilated cardiomyopathy, examined the benefit of ICD use by time since diagnosis. This
trial excluded patients with a clinical picture consistent with a reversible cause of cardiomyopathy and thus may differ from the population considered for a WCD. For the overall DEFINITE trial, there was a 35% reduction in overall mortality, but this difference did not meet statistical significance. In the reanalysis, patients were divided into recent diagnosis of cardiomyopathy (<3 months) and remote diagnosis (>9 months). The difference in survival was of borderline significance for the ICD group
compared with controls, both for the recently diagnosed subgroup (HR=0.38; 95% CI, 0.14 to 1.00; p=0.05), and the remotely diagnosed subgroup (HR=0.43; 95% CI, 0.22 to 0.99; p=0.046).
Kao et al reported on a prospective registry of 82 heart failure patients who were eligible for a WCD.(10) Dilated cardiomyopathy and EF less than 40% were diagnosed in 98.8% of patients and cardiac transplantation was indicated for 12 patients. During the study, use of the WCD was 75 (58) days during which time, no SCDs or deaths occurred. Improvement was reported in 41.5% of patients who no longer met the criteria for defibrillator use. ICD placement was reported in 34.1%.of patients and 1 patient received a heart transplant. As noted above, 13 patients (15.85%) did not wear the WCD due to refusal, discomfort or other/unknown reasons
The 2014 Uyei et al systematic review previously described identified 4 studies (Saltzberg et al ,(22) Chung et al ,(5) and 2 conference abstracts) that assessed WCD use in newly diagnosed nonischemic cardiomyopathy.(17) In the 3 studies that reported VT/VF incidence, an average 0.57% (5/871) subjects experienced VT and/or VF over a mean duration of 52.6 days. Among those who did experience a VT/VF event, an average 80% experienced successful event termination.
One study of WCD use in peripartum cardiomyopathy was published in 2012.(22) This study included 107 women with peripartum cardiomyopathy treated with a WCD device during the period of 2003 through 2009. Patients were identified from a registry of WCD use maintained by the manufacturer of the device. The average length of time that the WCD was used was 124 (123) days. During this time, there were no shocks delivered, either appropriate shocks or inappropriate shocks. There were also no patient deaths during the time of WCD treatment. Following discontinuation of the WCD, there were 3 deaths over a mean follow-up of 3.0 (1.2) years. In a matched group of 159 women with nonischemic cardiomyopathy who wore the WCD for 96 (83) days, there were 2 appropriate shocks and 11 deaths.
In a smaller study reported in 2014, Duncker et al reported outcomes for 12 prospectively enrolled women with peripartum cardiomyopathy who were treated at a single center and followed over a median of 12 months.(23) A WCD was recommended for 9 patients with LVEF of 35% or less and 7 of the 9 consented to wear the WCD. For these 7 patients, the median WCD wearing time was 81 days (mean, 133 days). In 3 patients, 4 episodes of VF were detected that led to delivery of a shock, which successfully terminated the arrhythmia in all cases. No inappropriate shocks were delivered. Among the 5 patients without WCD, no episodes of syncope, ventricular arrhythmias, or deaths occurred.
For patients with indications for an ICD but temporary contraindications, the use of a WCD for a temporary period of time is likely to improve outcomes. These patients are expected to benefit from an ICD, and the use of a WCD is a reasonable alternative because there are no other options for automatic detection and termination of ventricular arrhythmias.
Two RCTs of ICD use in the early postacute MI period concluded that mortality was not improved compared with usual care. In both these trials, SCD was reduced in the ICD group, but non-SCD was increased, resulting in no difference in overall mortality. One trial of high-risk post-CABG patients also reported no benefit from implantation of a permanent ICD. Because a permanent ICD does not appear to be beneficial in these situations, a WCD would also not be beneficial for these patient populations.
For other indications, evidence is lacking concerning the impact of a WCD on outcomes. Case series for these conditions are not sufficient to determine whether a WCD improves outcomes compared with usual care.
External Automatic Cardiac Defibrillators
Home use of an automatic external cardiac defibrillator is another potential alternative to either an ICD or a wearable defibrillator. However, there are no clinical trials that establish the efficacy of automatic external defibrillators for high-risk patients. Bardy et al(24) randomly assigned 7001 patients with anterior wall MI, who were not candidates for ICD implantation, to home external defibrillator or usual care. After a median follow-up of 37.3 months, there was no difference in mortality between groups (HR=0.97; 95% CI, 0.81 to 1.17). Therefore, home external defibrillators may not be a good alternative to ICD or WCD in high-risk patients.
Ongoing and Unpublished Clinical Trials
A search of online database ClinicalTrials.gov on December 10, 2014, identified 1 RCT evaluating WCDs that is ongoing:
- Vest Prevention of Early Sudden Death Trial and VEST Registry (NCT01446965): This is single-blinded RCT comparing WCD treatment with usual care in patients with recent MI and LVEF less than 35%. The primary outcome measure is mortality due to sudden death. Secondary outcomes are all-cause mortality, cardiovascular mortality, other cause-specific mortality, incidence of ventricular arrhythmias, adverse events due to the WCD, and compliance with the device. Enrollment is planned for 1900 subjects; the estimated study completion date is September 2015.
Several ongoing prospective cohort studies are evaluating the WCD in a variety of clinical settings, including among inpatients at risk for SCA (NCT02122549); in patients post-CABG with EF less than 35% (NCT01448005); in patients with LV dysfunction or heart failure at high risk of SCD who are not eligible for an ICD (NCT01326624); and in patients presenting to emergency departments postsyncope (NCT02188147).
Clinical Input Received From Physician Specialty Societies and Academic Medical Centers
While the various physician specialty societies and academic medical centers may collaborate with and make recommendations during this process through the provision of appropriate reviewers, input received does not represent an endorsement or position statement by the physician specialty societies or academic medical centers, unless otherwise noted.
In response to the request for input through physician specialty societies and academic medical centers, no input was received while this policy was under review for the April 2008 update.
In response to requests, input was received from no physician specialty societies and 4 academic medical centers while this policy was under review in 2010. Most, but not all, of those providing input suggested that the wearable defibrillator may have a role in selected high-risk patients following acute MI or in newly diagnosed cardiomyopathy.
In response to requests, input was received on the policy as a whole from 3 physician specialty societies and 8 academic medical centers while this policy was under review in 2013. Overall the input was mixed. Most, but not all, of those providing input suggested that the wearable defibrillator may have a role in selected high-risk patients following acute MI or in newly diagnosed cardiomyopathy. However, reviewers acknowledged the lack of evidence for benefit and that available evidence was not consistent in defining high-risk subgroups that may benefit.
In response to requests, further input was input was received from 2 physician specialty societies and 7 academic medical centers while this policy was under review in 2014, related to the role of WCDs in preventing SCD among high-risk patients awaiting a heart transplant. Overall, the input regarding the use of wearable defibrillators in this patient population was mixed. Some reviewers indicated that it may have a role among certain patients awaiting heart transplant, but there was not consensus on the specific patient indications for use.
Summary of Evidence
The available data establish that the wearable cardioverter defibrillator (WCD) device can detect lethal arrhythmias and can successfully deliver a countershock in most cases. There are a small number of patients who meet established criteria for an implantable cardioverter defibrillator (ICD) but have a transient contraindication for an implantable device, most commonly an infectious process. In these patients who are scheduled for ICD placement, the WCD may be considered medically necessary as an
interim treatment. The evidence shows that these patients benefit from a cardioverter defibrillator in general; and the WCD can detect and treat lethal arrhythmias in these patients.
For other bridging indications, particularly for the immediate post-myocardial infarction period, the evidence does not support the conclusion that the WCD improves outcomes. Two randomized controlled trials (RCTs) have reported that overall survival (OS) is not improved following treatment with a permanent ICD. While these 2 trials both reported a decrease in sudden cardiac death (SCD), there was a corresponding increase in non-SCD, resulting in no net benefit in survival. Similarly, for high-risk post
coronary artery bypass graft patients, 1 RCT reported no difference in OS associated with early ICD placement. Thus, given the lack of evidence that a permanent ICD improves outcomes for these indications, a WCD is not expected to improve outcomes and is therefore considered investigational.
For other potential indications, there are only case series or no relevant published evidence. Therefore it is not possible to conclude from the available evidence that net health outcome will be improved. These other indications, including bridge to transplantation, newly diagnosed nonischemic cardiomyopathy, and peripartum cardiomyopathy, are also considered investigational.
Practice Guidelines and Position Statements
Guidelines from the major cardiology specialty societies do not make specific recommendations for the use of WCD. For example, 2006 American College of Cardiology/American Heart Association (ACC/AHA) guidelines on the treatment of patients with ventricular arrhythmias(25) includes the following statement on WCD but does not include a formal recommendation: “The wearable automatic defibrillator has been approved in the United States by the FDA [Food and Drug Administration] for cardiac patients with a transient high risk for VF [ventricular fibrillation] such as those awaiting cardiac transplantation, those at very high risk after a recent MI [myocardial infarction] or an invasive cardiac procedure, or those requiring temporary removal of an infected implanted defibrillator for antibiotic therapy.” In 2014, the Heart Rhythm
Society, ACC, and AHA issued a consensus statement on the use of ICD therapy in patients who are not included or not well-represented in clinical trials.(26) The statement does not contain formal recommendations regarding WCD use, but states, “The wearable cardioverter-defibrillator (WCD) may be an option as a ‘bridge to ICD’ for selected patients at high risk of sudden cardiac death due to ventricular arrhythmias, although the data are scant.”
In 2014, the ACC and AHA issued guidelines on the management of non-ST-elevation acute coronary syndrome (NSTE-ACS).(27) These guidelines do not make specific recommendations regarding the use of WCDs, but do state the following:
“Life-threatening ventricular arrhythmias that occur >48 hours after NSTE-ACS are usually associated with LV dysfunction and signify poor prognosis. RCTs in patients with ACS have shown consistent benefit of implantable cardioverter-defibrillator therapy for survivors of VT or VF arrest. For other at-risk patients, especially those with significantly reduced LVEF, candidacy for primary prevention of sudden cardiac death with an implantable cardioverter-defibrillator should be readdressed ≥40 days after discharge. A life vest may be considered in the interim.”
In 2006, The International Society for Heart and Lung Transplantation issued guidelines for the care of cardiac transplant candidates that address the use of ICDs or WCDs.(28) Recommendations related to the use of WCDs include:
- Class I recommendations: An implanted or wearable ICD should be provided for Status 1B patients [ie, dependent on intravenous medications or a mechanical assist device] who are discharged home given that the wait for transplantation remains significant (Level of Evidence: C).
- Class IIa recommendations: It is reasonable to consider placement of a defibrillator in patients with Stage D failure who are candidates for transplantation or LVAD destination therapy (see subsequent considerations for mechanical circulatory support device [MCSD] referral: bridge or destination) (Level of Evidence: C).
U.S. Preventive Services Task Force Recommendations
Medicare National Coverage
There is no national coverage determination (NCD). In the absence of an NCD, coverage decisions are left to the discretion of local Medicare carriers.
- U.S. Food and Drug Administration. Summary of Safety and Effectiveness Data, P010030, Lifecor, Inc, WCD® 2000 System. http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cftopic/pma/pma.cfm?num=P010030. Accessed September 16, 2013.
- Beauregard LA. Personal security: clinical applications of the wearable defibrillator. Pacing Clin Electrophysiol. 2004;27(1):1-3.
- Blue Cross and Blue Shield Association Technology Evaluation Center (TEC). Wearable cardioverter-defibrillator as a bridge to implantable cardioverter-defibrillator treatment. TEC Assessments. 2010;Volume 25, Tab 2.
- Auricchio A, Klein H, Geller CJ, et al. Clinical efficacy of the wearable cardioverter-defibrillator in acutely terminating episodes of ventricular fibrillation. Am J Cardiol. 1998;81(10):1253-1256.
- Chung MK, Szymkiewicz SJ, Shao M, et al. Aggregate national experience with the wearable cardioverterdefibrillator: event rates, compliance, and survival. J Am Coll Cardiol. Jul 13 2010;56(3):194-203. PMID 20620738
- Tanawuttiwat T GJ, Salow A et al. Protection from Outpatient Sudden Cardiac Death following ICD Removal Using a Wearable Cardioverter Defibrillator. PACE. 2013 2013;00:1-7.
- Feldman AM, Klein H, Tchou P, et al. Use of a wearable defibrillator in terminating tachyarrhythmias in patients at high risk for sudden death: results of the WEARIT/BIROAD. Pacing Clin Electrophysiol. 2004;27(1):4-9.
- Goldenberg I KH, Zareba W et al. Eighteen Month Results From The Prospective Registry And Follow-up Of Patients Using The Lifevest Wearable Defibrillator (WEARIT-II Registry) - LB02-02. Heart Rhythm 2013 - 34th Annual Scientific Sessions; May 10, 2013.
- Mitrani RD, McArdle A, Slane M, et al. Wearable defibrillators in uninsured patients with newly diagnosed cardiomyopathy or recent revascularization in a community medical center. Am Heart J. Mar 2013;165(3):386-392. PMID 23453108
- Kao AC, Krause SW, Handa R, et al. Wearable defibrillator use in heart failure (WIF): results of a prospective registry. BMC Cardiovasc Disord. 2012;12:123. PMID 23234574
- Gregoratos G, Cheitlin MD, Conill A, et al. ACC/AHA guidelines for implantation of cardiac pacemakers and arrhythmia devices: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Committee on Pacemaker Implantation). J Am Coll Cardiol. 1998;31(5):1175-1209.
- AVID Investigators. A comparison of antiarrhythmic-drug therapy with implantable defibrillators in patients resuscitated from near-fatal ventricular arrhythmias. The Antiarrhythmics versus Implantable Defibrillators (AVID) Investigators. N Engl J Med. 1997;337(22):1576-1583.
- Wilber DJ, Zareba W, Hall WJ, et al. Time dependence of mortality risk and defibrillator benefit after myocardial infarction. Circulation. 2004;109(9):1082-1084.
- Hohnloser SH, Kuck KH, Dorian P, et al. Prophylactic use of implantable cardioverter-defibrillator after acute myocardial infarction. N Engl J Med. 2004;351(24):2481-2488.
- Steinbeck G, Andresen D, Seidl KII, et al. Defibrillator implantation early after myocardial infarction. N Engl J Med. 2009;361(15):1427-1436.
- Epstein AE, Abraham WT, Bianco N, et al. Wearable Cardioverter-Defibrillator Use in Patients Perceived to be at High Risk Early Post Myocardial Infarction. J Am Coll Cardiol. Jul 20 2013. PMID 23916930
- Uyei J, Braithwaite RS. Effectiveness of wearable defibrillators: systematic review and quality of evidence. Int J Technol Assess Health Care. Apr 2014;30(2):194-202. PMID 24893969
- Bigger JT. Prophylactic use of implanted cardiac defibrillators in patients at high risk for ventricular arrhythmias after coronary-artery bypass surgery. The CABG-PATCH Trial Investigators. N Engl J Med. 1997;337(22):1569-1575.
- Zishiri ET, Williams S, Cronin EM, et al. Early risk of mortality after coronary artery revascularization in patients with left ventricular dysfunction and potential role of the wearable cardioverter defibrillator. Circ Arrhythm Electrophysiol. Feb 2013;6(1):117-128. PMID 23275233
- Rao M, Goldenberg I, Moss AJ, et al. Wearable defibrillator in congenital structural heart disease and inherited arrhythmias. Am J Cardiol. Dec 1 2011;108(11):1632-1638. PMID 21890075
- Kadish A, Schaechter A, Subacius H, et al. Patients with recently diagnosed nonischemic cardiomyopathy benefit from implantable cardioverter-defibrillators. J Am Coll Cardiol. 2006;47(12):2477-2482.
- Saltzberg MT, Szymkiewicz S, Bianco NR. Characteristics and outcomes of peripartum versus nonperipartum cardiomyopathy in women using a wearable cardiac defibrillator. J Card Fail. Jan 2012;18(1):21-27. PMID 22196837
- Duncker D, Haghikia A, Konig T, et al. Risk for ventricular fibrillation in peripartum cardiomyopathy with severely reduced left ventricular function-value of the wearable cardioverter/defibrillator. Eur J Heart Fail. Nov 5 2014. PMID 25371320
- Bardy GH, Lee KL, Mark DB, et al. Home use of automated external defibrillators for sudden cardiac arrest. N Engl J Med. 2008;358(17):1793-1804.
- Zipes DP, Camm AJ, Borggrefe M, et al. ACC/AHA/ESC 2006 guidelines for management of patients with ventricular arrhythmias and the prevention of sudden cardiac death: a report of the American College of Cardiology/American Heart Association Task Force and the European Society of Cardiology Committee for Practice Guidelines (Writing Committee to Develop Guidelines for Management of Patients With Ventricular Arrhythmias and the Prevention of Sudden Cardiac Death). J Am Coll Cardiol. Sep 5 2006;48(5):e247-346. PMID 16949478
- Kusumoto FM, Calkins H, Boehmer J, et al. HRS/ACC/AHA Expert Consensus Statement on the Use of Implantable Cardioverter-Defibrillator Therapy in Patients Who Are Not Included or Not Well Represented in Clinical Trials. Circulation. July 1, 2014 2014;130(1):94-125.
- Amsterdam EA, Wenger NK, Brindis RG, et al. 2014 AHA/ACC Guideline for the Management of Patients With Non–ST-Elevation Acute Coronary Syndromes: A Report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines. Circulation. December 23, 2014 2014;130(25):e344-e426.
- Gronda E, Bourge RC, Costanzo MR, et al. Heart rhythm considerations in heart transplant candidates and considerations for ventricular assist devices: International Society for Heart and Lung Transplantation guidelines for the care of cardiac transplant candidates--2006. J Heart Lung Transplant. Sep 2006;25(9):1043-1056. PMID 16962465
Interrogation device evaluation (in person) with physician analysis, review and report, includes connection, recording and disconnection per patient encounter; wearable defibrillator system
|93745||Initial setup and programming by a physician of wearable cardioverter-defibrillator includes initial programming of system, establishing baseline electronic electrocardiogram, transmission of data to data repository, patient instruction in wearing system, and patient reporting of problems or events|
Automatic external defibrillator, with integrated electrocardiogram analysis, garment type
Replacement battery for automated external defibrillator, each
Replacement garment for use with automated external defibrillator, each
Replacement electrodes for use with automated external defibrillator, each
|ICD-9 diagnosis||425.1; 425.4||Hypertrophic cardiomyopathy codes|
|427.1||paroxysmal ventricular tachycardia|
|427.9||Cardiac dysrhythmia, unspecified (ventricular arrhythmia code)|
|ICD-10-CM (effective 10/1/15)||I42.0-I43||Cardiomyopathy code range|
|I47.0-I47.9||Paroxysmal tachycardia code range|
|I49.01- I49.02||Ventricular fibrillation and flutter code range|
|I50.1 – I50.9||Heart failure code range|
|Z86.74||Personal history of sudden cardiac arrest|
|ICD-10-PCS (effective 10/1/15)||ICD-10-PCS codes are only used for inpatient services. There is no specific ICD-10-PCS code for the initiation or application of this therapy. They might use the following code:|
|5A2204Z||Extracorporeal assistance and performance, physiological systems, restoration, cardiac, rhythm|
Cardioverter Defibrillator, Wearable Vest
LifeCor WCD System
Wearable Cardiac Defibrillator
|04/29/03||Add to Medicine section||New policy|
|07/15/04||Replace policy||Policy updated; no change in policy statement, no additional references identified|
|11/9/04||Replace policy||Coding updated. New 2005 CPT codes for data analysis added|
|06/27/05||Replace policy||Policy updated with literature review; no changes in policy statement; references numbers 4, 6-8 added.|
|10/10/06||Replace policy||Policy updated with literature review for March 2005 through August 2006; no change in policy statement.|
|02/15/07||Replace policy||Policy updated with literature review through December 2006. Policy statement updated with medically necessary indications for interim treatment|
|04/09/08||Replace policy||Policy updated with literature review; no change in policy statements.|
|09/10/09||Replace policy||Policy updated with literature review; references 8 and 10 added; no change in policy statements. Policy title shortened to “Wearable Cardioverter-Defibrillators.” CPT coding updated.|
|05/13/10||Replace policy||Policy updated with literature search/TEC Assessment. Rationale and references extensively revised. No change in policy statements. ICD-9-CM diagnosis codes and CPT code 93292 added.|
|10/08/10||Replace policy||Clinical input reviewed, policy statements unchanged|
|10/04/11||Replace policy||Policy updated with literature review, reference 12 added. No change to policy statement.|
|11/8/12||Replace Policy-Correction Only||Added statement from 2006 ACC/AHA/ESC guidelines that was mistakenly left off of the Clinical Practice Guidelines and Position Statements section.|
|10/10/13||Replace policy||Policy updated with literature review through August 2013, references 6-7, 13, and 15 added. Clinical input reviewed. Added post-CABG surgery, newly diagnosed nonischemic cardiomyopathy and peripartum cardiomyopathy to investigational policy statement. Removed “as a Bridge to Implantable Cardioverter-Defibrillator Placement” from the title.|
|01/09/14||Replace policy||Policy updated with literature review through December 5, 2013; references 5 and 7 added. Clinical input reviewed. “High-risk patients awaiting heart transplant” was added to the investigational policy statement; and an additional policy statement that use of wearable cardioverter-defibrillators is considered investigational for all other indications was added.|
|1/15/15||Replace policy||Policy updated with literature review through November 30, 2014. References 17, 23, and 26-27 added. Policy statements unchanged.|