Implantable Cardioverter-Defibrillators

Aetna considers Food and Drug Administration-approved implantable cardioverter-defibrillators (thoracotomy and non-thoracotomy systems) medically necessary for any of the following groups of individuals, except where contraindicated:

1. Members after one or more episodes of spontaneously occurring and inducible ventricular fibrillation (VF), or syncopal or hypotensive ventricular tachycardia (VT) that is not associated with acute myocardial infarction (AMI)]; and not due to a remediable cause (e.g., drug toxicity, electrolyte abnormalities, ischemia); or
2. Members after spontaneously occurring but non-inducible documented syncopal or hypotensive VT that was not due to AMI; or
3. Members after VT/VF cardiac arrest that was not associated with an inducible ventricular arrhythmia, and not due to AMI; or
4. Members with structural heart disease (such as prior myocardial infarction (MI), congenital heart disease, and/or ventricular dysfunction) and spontaneous, sustained VT (greater than 30 seconds), whether hemodynamically stable or unstable. Note; ICD may also be considered for persons with sustained VT and normal ventricular function; or
5. Members after unexplained syncope, which by history and clinical circumstances was probably due to a ventricular tachyarrhythmia, with either of the following: 1) the presence of reproducible inducible syncopal or hypotensive VT or VF that is not associated with AMI and not due to a remediable cause; or 2) significant left ventricular (LV) dysfunction (LV ejection fraction less than 50%), and structural heart disease such as prior myocardial infarction (MI), congenital heart disease, and/or ventricular dysfunction; or
6. Members with ischemic dilated cardiomyopathy* with a history of heart attack and one of the following: 1) New York Heart Association (NYHA) Class II or III heart failure (see appendix) with a LVEF less than or equal to 35%, who are at least 40 days post MI, and are on optimal medical therapy, defined as 3 months of maximally titrated doses as tolerated of an ACE inhibitor, beta-blocker, and diuretic; or 2) NYHA Class I heart failure (see appendix) with a LVEF less than or equal to 30%, who are at least 40 days post MI, and are on optimum medical therapy; or 3) non-sustained VT due to prior MI, and LVEF less than or equal to 40%, and inducible VF or sustained VT at EP study performed at least 96 hours after revascularization or MI; or
7. Members with non-ischemic dilated cardiomyopathy, NYHA Class II or III heart failure (see appendix), and a LVEF less than or equal to 35 % who are on optimal medical therapy, defined as 3 months of maximally titrated doses as tolerated of an ACE inhibitor, beta-blocker, and diuretic; or

8. Members with familial or inherited conditions with a high-risk of life-threatening ventricular tachyarrhythmias, including:

   1. Long QT syndrome with either of the following:

      1. Syncope and/or VT while receiving beta-blockers; or

      2. Asymptomatic with one or more of the following risk factors for sudden cardiac death:

         1. QTc greater than 500 msec, or
         2. LQT2 or LQT3; or

         3. Family history of sudden death

   2. Hypertrophic cardiomyopathy or arrhythmogenic right ventricular cardiomyopathy (ARVC) with one or more of the following risk factors for sudden cardiac death:

      1. Documented VT; or
      2. Family history of sudden cardiac death in at least one first-degree relative; or
      3. Left ventricular thickness of 3 cm or greater; or
      4. Hypotensive response to exercise treadmill testing (ETT); or

      5. At least one episode of unheralded syncope within the previous 12 months.

   3. Catecholaminergic polymorphic VT who have syncope and/or documented sustained VT while receiving beta-blockers.
   4. Brugada Syndrome who have had syncope or who have documented or inducible VT.

   5. LV non-compaction cardiomyopathy with either of the following:

      1. Positive family history of sudden cardiac death; or

      2. Impaired left ventricular ejection fraction (less than 50%)

   6. Cardiac sarcoidosis, giant cell myocarditis, or Chagas disease, regardless of LV ejection fraction
   7. ICD implantation may be considered in affected members with a familial cardiomyopathy associated with sudden death.

* Note: Ischemic cardiomyopathy is defined as left ventricular systolic dysfunction associated with marked stenosis (at least 75% narrowing) of at least 1 of the 3 major coronary arteries, or a documented history of myocardial infarction.

Aetna considers implantable cardioverter-defibrillators experimental and investigational for other indications because its safety and effectiveness has not been established.

Contraindications:

Implantable cardioverter-defibrillators are not considered medically necessary in any of the following situations:

1. When other disease processes are present that clearly and severely limit the member's life expectancy.

Notes: Electronic analysis of defibrillator systems is required for long-term routine follow-up care of implantable cardioverter-defibrillators. Automatic defibrillator monitoring is considered medically necessary. Electrophysiologic assessment is a more complex evaluation of newly or chronically implanted cardioverter-defibrillators, and is considered medically necessary.

Note: Intracardiac electrophysiological procedures performed before implantation of cardioverter-defibrillator may be done as an outpatient.

See also CPB 579 - T-Wave Alternans, and CPB 610 - Biventricular Pacing (Cardiac Resynchronization Therapy)/Combination Resynchronization-Defibrillation Devices for Congestive Heart Failure.

Wearable Cardioverter-Defibrillators

Aetna considers wearable cardioverter-defibrillators (WCDs) (automatic external cardioverter-defibrillators that are worn under the member's clothing) medically necessary durable medical equipment (DME) only for members who meet any of the following  criteria:  

• A documented episode of VF or a sustained, lasting 30 seconds or longer, VT (these dysrhythmias may be either spontaneous or induced during an electrophysiologic (EP) study, but may not be due to a transient or reversible cause and not occur during the first 48 hours of an AMI); or
• A previously implanted defibrillator now requires explantation; or
• Either documented prior myocardial infarction or dilated cardiomyopathy and a measured LVEF less than or equal to 35 %; or
• Familial or inherited conditions with a high risk of life-threatening VT such as long QT syndrome or hypertrophic cardiomyopathy.

Aetna considers WCDs experimental and investigational for other indications because its safety and effectiveness has not been established.

For Aetna's policy on automatic external defibrillators (AEDs) for home use, see CPB 623 - Safety Items.

Cardiovascular mortality as a consequence of ventricular fibrillation (VF) or ventricular tachycardia (VT) continues to be a major health problem despite advances in the overall management of cardiovascular disease. Sudden cardiac death kills approximately 400,000 people per year. About 10 to 15 % of individuals who experience life threatening VT or VF recover, usually with an external cardiac defibrillator. These survivors have various therapeutic options such as anti-arrhythmic drugs, radiofrequency or surgical ablation of VT focus, or implantable cardioverter-defibrillators (ICDs).

Available literature indicates ICDs are now widely used for the secondary prevention of sudden cardiac death due to VF or VT. Ventricular tachycardia or VF can be secondary to a variety of conditions: progression in underlying pathology (i.e., deterioration of left ventricular [LV] function or worsening of coronary artery disease), autonomic imbalance, electrolyte abnormalities or even pharmacological intervention. The ICD is generally accepted as treatment for patients who have experienced an episode of VF not accompanied by an acute myocardial infarction or other transient or reversible causes (e.g., drug toxicity, electrolyte abnormalities, and ischemia). Additionally, accepted guidelines prefer this treatment in patients with sustained VT causing syncope or hemodynamic compromise. As primary prevention, the literature shows the ICD is superior to conventional anti-arrhythmic drug therapy in patients who have survived a myocardial infarction and who have spontaneous, non-sustained VT, a low ejection fraction, inducible VT at electrophysiological study, and whose VT is not suppressed by procainamide.

A number of well-designed studies have shown the effectiveness of the ICD in high-risk patients who have already experienced a myocardial infarction (MI). Schlapfer and colleagues (2002) compared the long-term survival rates of patients with sustained ventricular tachyarrhythmia after MI who were treated according to the results of EP study either with amiodarone or an ICD. They found that the long-term survival of patients with sustained ventricular tachyarrhythmias after MI, with depressed LV function, is significantly better with an ICD than with amiodarone therapy, even when stratified according to the results of the EP study. In a randomized controlled study (n = 1,232) to evaluate the effect of an implantable defibrillator on survival of patients with reduced LV function after MI, Moss et al (2002) concluded that in patients with a prior MI and advanced LV dysfunction, prophylactic implantation of a defibrillator improves survival and should be considered as a recommended therapy.

The Multi-center Autonomic Defibrillator Implantation Trial II (MADIT II) was stopped early because of a 30 % reduction in mortality in patients randomized to receive an ICD (Coats, 2002). The 4-year multi-center trial of 1,200 patients was terminated early after an independent board observed that the post-MI patients with impaired LV function receiving the implantable defibrillator had improved survival rates compared to those receiving conventional treatment.

The Center for Medicare and Medicaid Services (CMS) determined that the evidence is adequate to conclude that an ICD is reasonable and necessary for the following: (i) patients with ischemic dilated cardiomyopathy (IDCM), documented prior MI, and a measured LVEF of less than or equal to 35 %; (ii) patients with non-ischemic dilated cardiomyopathy (NIDCM) greater than 9 months with a measured EF less than or equal to 35 %.

In addition, according to CMS, several additional criteria must be met. Patients must not have: New York Heart Association (NYHA) Class IV heart failure; cardiogenic shock or symptomatic hypotension while in a stable baseline rhythm; coronary artery bypass graft or percutaneous transluminal coronary angioplasty within the past 3 months; acute myocardial infarction (AMI) within the past month; clinical symptoms or findings that would make them a candidate for coronary revascularization; irreversible brain damage from pre-existing cerebral disease; or any disease, other than cardiac disease (e.g., cancer, uremia, liver failure) associated with a likelihood of survival less than 1 year.

The Center for Medicare and Medicaid Services expanded coverage of ICDs to persons with NIDCM, based primarily on the results of the Sudden Cardiac Death in Heart Failure Trial (SCD-HeFT), a prospective randomized trial to determine whether amiodarone or an ICD will improve survival compared to placebo in patients with NYHA Class II and Class III heart failure and reduced LVEF less than 35 %. The study included persons with NIDCM and patients with ischemic dilated cardiomyopathy. A total of 2,521 patients were enrolled, 847 of whom were assigned to placebo plus conventional heart failure therapy, 845 to amiodarone plus conventional heart failure therapy, and 829 to single lead ICD plus conventional heart failure therapy. There was a significant reduction in all-cause mortality in the ICD group compared to the placebo group (hazard ratio compared to control = 0.77; 97.5 % confidence intervals [CI]: 0.62 to 0.96, p = 0.007). For patients with ischemic dilated cardiomyopathy, there was a reduction in mortality hazard ratio compared to control but it was not statistically significant (hazard ratio 0.79; 97.5 % CI: 0.60 to 1.04). For patients with NIDCM, there was a reduction in the mortality hazard ratio for ICD therapy compared to control but it was also not statistically significant (hazard ratio 0.73; 97.5 % CI: 0.50 to1.07). CMS noted that the absolute reduction in mortality was modest for a trial with a median follow-up of 45.5 months.

Patients with arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C) are characterized by progressive degeneration of the right ventricular myocardium, ventricular arrhythmias, fibrous-fatty replacement, and increased risk of sudden death. Mutations in 6 genes, including 4 encoding desmosomal proteins (junctional plakoglobin, desmoplakin, plakophilin 2, and desmoglein 2), have been identified in patients with ARVD/C. The potential use of genetic screening for desmoglein 2 mutations is for identifying persons at increased risk of ARVD/C who are candidates for prophylactic ICD. Currently, there are no prospective studies of the use of desmoglein 2 genetic testing for selecting ICD candidates. About one-third of individuals with ARVD/C have been reported to have mutations in the desmoglein 2 gene or other associated mutations (Franz et al, 2001), and it is unknown what proportion of asymptomatic persons who have desmoglein 2 mutations go on to develop ARVD/C. Thus, the risks and benefits of prophylactic ICD implantation in persons with mutations of this gene are unknown.

Marenco et al (2001) conducted a systematic review of the literature on the use of automatic external defibrillators (AEDs). Most of the literature on AEDs discusses their use by emergency medical technician or ambulance staff. The authors summarized the literature on use of AEDs by non-medical persons in the home:

Because the majority of cardiac arrests occur at home, several studies have examined the use of AEDs by family members of high-risk patients. Although these studies demonstrated the feasibility of training laypersons (e.g., family members) to use an AED, researchers had difficulty with patient recruitment and obtained disappointing results. There is mounting evidence for the efficacy of ICDs in patients at increased risk for sudden cardiac death. This has limited enthusiasm for the placement of AEDs in the home of high-risk patients and primarily limited the role of the AED in the home to high-risk patients who either refuse an ICD or have a contraindication to ICD placement. However, these studies used earlier-generation AEDs and, given the lower costs and ease of use of the current devices, further study with the newer technology is warranted.

An assessment of AEDs for home use by the Canadian Coordinating Centre for Health Technology Assessment (CCOHTA) (Murray and Steffensen, 2005) found: “No prospective studies demonstrate that the use of AEDs in the home by untrained persons improves health outcomes. Further investigation is needed to determine the benefit and harm of AEDs in the home”.

Because there are no prospective clinical studies demonstrating that use of AEDs by non-medical persons for home use improves health outcomes, Aetna considers wearable automatic external cardioverter defibrillators (wearable cardioverter-defibrillators or WCDs) medically necessary only on an exception basis for high-risk patients who meet the criteria for an ICD and who either refuse an ICD or have a contraindication to ICD placement.

The first multi-center randomized controlled clinical study to examine the use of at-home AEDs found that the devices do not improve overall survival when compared to conventional resuscitation methods, such as cardiopulmonary resuscitation (CPR). Bardy et al (2008) randomly assigned 7,001 patients with previous anterior-wall MI who were not candidates for an ICD to receive 1 of 2 responses to sudden cardiac arrest occurring at home: either the control response (calling emergency medical services and performing CPR) or the use of an AED, followed by calling emergency medical services and performing CPR. The primary outcome was death from any cause. The median age of the patients was 62 years; 17 % were women. The median follow-up was 37.3 months. Overall, 450 patients died: 228 of 3,506 patients (6.5 %) in the control group and 222 of 3,495 patients (6.4 %) in the AED group (hazard ratio, 0.97; 95 % CI: 0.81 to 1.17; p = 0.77). Mortality did not differ significantly in major pre-specified subgroups. Only 160 deaths (35.6 %) were considered to be from sudden cardiac arrest from tachyarrhythmia. Of these deaths, 117 occurred at home; 58 at-home events were witnessed. Automatic external defibrillators were used in 32 patients. Of these patients, 14 received an appropriate shock, and 4 survived to hospital discharge. There were no documented inappropriate shocks. The authors concluded that for survivors of anterior-wall MI who were not candidates for ICD, access to a home AED did not significantly improve overall survival, as compared with reliance on conventional resuscitation methods.

Exner (2009) stated that most sudden cardiac death (SCD) events occur in patients with less severe LV dysfunction, yet past trials and guidelines focus on those with severe LV dysfunction. Given the large pool of patients with less severe LV dysfunction and a modest risk of SCD, methods to identify those who might benefit from an ICD are needed. Observational studies indicate that abnormal cardiac repolarization and impaired autonomic function, especially in combination, appear to identify patients with less severe LV dysfunction at risk of SCD. Extensive scarring also appears to identify patients at risk. Ongoing and planned studies will better define the role of using non-invasive tests to select patients for ICD therapy. The author concluded that non-invasive measures of cardiac structure, autonomic function and myocardial substrate appear to be promising in identifying patients with less severe LV dysfunction at risk of SCD. However, it is unclear if ICD therapy will improve survival in these patients. Until definitive data from prospective, randomized trials are available it is premature to recommend use of these tools to guide ICD therapy.

Tsai et al (2009) noted that SCD among orthotopic heart transplant recipients is an important mechanism of death after cardiac transplantation. The role for ICDs in this population is not well-established. These researchers examined if ICDs are effective in preventing SCD in high-risk heart transplant recipients. They retrospectively analyzed the records of all orthotopic heart transplant patients who had ICD implantation between January 1995 and December 2005 at 5 heart transplant centers. A total of 36 patients were included in this study. The mean age at orthotopic heart transplant was 44 +/- 14 years, the majority being male (n = 29). The mean age at ICD implantation was 52 +/- 14 years, whereas the average time from orthotopic heart transplant to ICD implant was 8 +/- 6 years. The main indications for ICD implantation were severe allograft vasculopathy (n = 12), unexplained syncope (n = 9), history of cardiac arrest (n = 8), and severe left ventricular dysfunction (n = 7). Twenty-two shocks were delivered to 10 patients (28 %), of whom 8 (80 %) received 12 appropriate shocks for either rapid VT or VF. The shocks were effective in terminating the ventricular arrhythmias in all cases. Three (8 %) patients received 10 inappropriate shocks. Underlying allograft vasculopathy was present in 100 % (8 of 8) of patients who received appropriate ICD therapy. The authors concluded that use of ICDs after heart transplantation may be appropriate in selected high-risk patients. They stated that more studies are needed to establish an appropriate prevention strategy in this population.

Appendix

New York Heart Association Functional Classification of Cardiac Disability:

Class I: Patients with cardiac disease but without resulting limitations of physical activity. Ordinary physical activity does not cause undue fatigue, palpitation, dyspnea, or anginal pain.

Class II: Patients with cardiac disease resulting in slight limitation of physical activity. They are comfortable at rest. Ordinary physical activity results in fatigue, palpitation, dyspnea, or anginal pain.

Class III: Patients with cardiac disease resulting in marked limitation of physical activity. They are comfortable at rest. Less than ordinary physical activity causes fatigue, palpitation, dyspnea, or anginal pain.

Class IV: Patients with cardiac disease resulting in inability to carry on any physical activity without discomfort. Symptoms of cardiac insufficiency or of the anginal syndrome may be present even at rest. If any physical activity is undertaken, discomfort is increased.

Source: Adapted from Goldman et al (1981).