Skip to content
evident
Original paper
2005NEJMCardiology

SCD-HeFT

Amiodarone or an implantable cardioverter-defibrillator for congestive heart failure

RCTSudden death prevention

On this page

Overview

In NYHA II-III HFrEF, ICD therapy reduced mortality while amiodarone did not.

Clinical takeaway

SCD-HeFT anchored primary-prevention ICD use in symptomatic HFrEF with low EF across ischemic and nonischemic cardiomyopathy.

Key result

ICD therapy reduced all-cause mortality versus placebo; amiodarone did not improve survival.

Practice impact

ICDs became standard primary-prevention therapy for selected patients with persistent low EF despite medical therapy.

Evidence

Study design

Randomized controlled trial with placebo, amiodarone, and ICD arms.

Enrollment

2,521

Follow-up

Median 45.5 months.

Geography

United States, Canada, New Zealand

Clinical question

Do amiodarone or an ICD improve survival in NYHA II-III heart failure with reduced ejection fraction?

Population

  • Patients with NYHA class II or III heart failure and left ventricular ejection fraction <=35%.
  • Included ischemic and nonischemic cardiomyopathy.

Intervention

Amiodarone or conservatively programmed single-lead ICD.

Comparator

Placebo medical therapy.

Primary outcome

All-cause mortality.

ICD therapy reduced all-cause mortality in selected patients with symptomatic HFrEF.

Hazard ratio / 0.77 / 97.5% CI 0.62-0.96 / p=0.007

Key results

  • ICD therapy reduced all-cause mortality by 23% relative to placebo: 22% vs 29% died; HR 0.77; 97.5% CI 0.62-0.96; p=0.007 (absolute reduction 7.2 percentage points at 5 years).
  • Amiodarone did not improve survival compared with placebo: 28% vs 29% died; HR 1.06; 97.5% CI 0.86-1.30; p=0.53.
  • Benefit was most apparent in NYHA class II patients.

Harms

  • ICDs can cause inappropriate shocks, procedural complications, infection, and downstream generator-lead issues.
  • Amiodarone has thyroid, pulmonary, hepatic, ocular, and drug-interaction toxicity.

Clinical Use

Practice impact

  • Helped define primary-prevention ICD criteria for symptomatic HFrEF with persistently low EF.

Applicability

  • Patients with reasonable life expectancy, NYHA II-III symptoms, and EF <=35% despite optimized medical therapy.

Limitations

  • Medical therapy has evolved substantially since the trial.
  • Device selection and programming differ from contemporary ICD practice.

Common misinterpretations

  • Do not implant immediately after a new HF diagnosis without time for GDMT and EF reassessment when guidelines recommend waiting.

Related evidence

MADIT-II - Similar QuestionCAST - Contrasting Result

Citation

Bardy GH, Lee KL, Mark DB, et al. Amiodarone or an implantable cardioverter-defibrillator for congestive heart failure. N Engl J Med. 2005;352(3):225-237. doi:10.1056/NEJMoa043399

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.