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Published on: February 28, 2012
Amiodarone or an implantable cardioverter-defibrillator for congestive heart failure
Gust H Bardy1, Kerry L Lee, Daniel B Mark
1Seattle Institute for Cardiac Research, Seattle, WA 98103, USA. gbardy@sicr.org
Insights
Sudden cardiac death in heart failure patients is a concern. Implantable cardioverter-defibrillator (ICD) therapy significantly reduced mortality by 23% compared to placebo, while amiodarone showed no survival benefit.
Area of Science:
- Cardiology
- Clinical Trials
- Heart Failure Management
Background:
- Sudden cardiac death is a primary cause of mortality in congestive heart failure (CHF) patients.
- Amiodarone and implantable cardioverter-defibrillators (ICDs) are potential interventions to improve prognosis.
Purpose of the Study:
- To compare the efficacy of amiodarone and ICD therapy versus conventional therapy in reducing mortality in CHF patients.
- To evaluate the impact of these treatments on overall survival rates.
Main Methods:
- A randomized trial involving 2521 patients with NYHA class II/III CHF and LVEF ≤ 35%.
- Patients were assigned to conventional therapy with placebo, amiodarone, or a single-lead, shock-only ICD.
- The primary endpoint was all-cause mortality, with a median follow-up of 45.5 months.
Main Results:
- ICD therapy was associated with a 23% reduction in the risk of death compared to placebo (HR, 0.77; P=0.007).
- Amiodarone showed no significant difference in mortality risk compared to placebo (HR, 1.06; P=0.53).
- ICD therapy resulted in an absolute mortality reduction of 7.2 percentage points after five years.
Conclusions:
- In patients with moderate to severe CHF and reduced ejection fraction, amiodarone does not improve survival.
- Single-lead, shock-only ICD therapy is effective in reducing overall mortality in this patient population.
Background:
Sudden death from cardiac causes remains a leading cause of death among patients with congestive heart failure (CHF). Treatment with amiodarone or an implantable cardioverter-defibrillator (ICD) has been proposed to improve the prognosis in such patients.
Methods:
We randomly assigned 2521 patients with New York Heart Association (NYHA) class II or III CHF and a left ventricular ejection fraction (LVEF) of 35 percent or less to conventional therapy for CHF plus placebo (847 patients), conventional therapy plus amiodarone (845 patients), or conventional therapy plus a conservatively programmed, shock-only, single-lead ICD (829 patients). Placebo and amiodarone were administered in a double-blind fashion. The primary end point was death from any cause.
Results:
The median LVEF in patients was 25 percent; 70 percent were in NYHA class II, and 30 percent were in class III CHF. The cause of CHF was ischemic in 52 percent and nonischemic in 48 percent. The median follow-up was 45.5 months. There were 244 deaths (29 percent) in the placebo group, 240 (28 percent) in the amiodarone group, and 182 (22 percent) in the ICD group. As compared with placebo, amiodarone was associated with a similar risk of death (hazard ratio, 1.06; 97.5 percent confidence interval, 0.86 to 1.30; P=0.53) and ICD therapy was associated with a decreased risk of death of 23 percent (0.77; 97.5 percent confidence interval, 0.62 to 0.96; P=0.007) and an absolute decrease in mortality of 7.2 percentage points after five years in the overall population. Results did not vary according to either ischemic or nonischemic causes of CHF, but they did vary according to the NYHA class.
Conclusions:
In patients with NYHA class II or III CHF and LVEF of 35 percent or less, amiodarone has no favorable effect on survival, whereas single-lead, shock-only ICD therapy reduces overall mortality by 23 percent.
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