SCD-HeFT: ICD cuts all-cause mortality by 23% in NYHA class 2-3 heart failure

March 08, 2004

New Orleans, LA - A randomized, controlled trial found that treatment with an implantable cardioverter defibrillator (ICD) on top of standard medications reduced the hazard ratio for five-year all-cause mortality by 23% compared with a control group in a broad population of patients with HF and LV dysfunction. Patients in the Sudden Cardiac Death in Heart Failure Trial (SCD-HeFT), which was reported here by Dr Gust Bardy (Seattle Institute for Cardiac Research, WA), included patients with NYHA class 2-3 HF of either ischemic or nonischemic etiology and an LVEF <35%.

SCD-HeFT also compared primary therapy with amiodarone with placebo; amiodarone had no effect on survival. The 2521-patient trial was conducted at 148 centers in North America and New Zealand.

"The ICD saves lives and amiodarone doesn't in class 2 or 3 [heart failure], with or without ischemic heart disease," Bardy told heartwire . Patients who match the SCD-HeFT entry criteria, he said, should receive a single-chamber ICD "unless there's a reason not to."

The ICD saves lives and amiodarone doesn't in class 2 or 3 [heart failure], with or without ischemic heart disease.

After his formal presentation of the SCD-HeFT results, Bardy said that the trial was designed to have broad application in HF. "We chose a broad swath" of the calculated four to five million Americans with HF, he said, estimating that the findings suggest the ICD may be appropriate for "two or three if not four" million of them.

Dr Stuart Connolly (McMaster University, Hamilton, ON), speaking to heartwire after hearing the SCD-HeFT results, said he thinks it's appropriate now to use an ICD in patients with an LVEF from between 35% and >30% if they have symptoms and in patients with an LVEF <30% "whether or not they have symptoms." He bases those criteria, he said, on the design and findings of both SCD-HeFT and the Multicenter Automatic Defibrillator Implantation Trial (MADIT II). (Heartwire reviewed the methodologies of both trials and the findings of MADIT II and related studies in a recent companion article.)

The controlled MADIT-II study showed a significant all-cause mortality reduction with ICD therapy in a post-MI population with an LVEF <30%. When the Centers for Medicare & Medicaid Services updated its ICD policies to acknowledge the results, it added a requirement that for reimbursement, ICD recipients should have a QRS duration >120 ms. That risk-stratification requirement was not part of either SCD-HeFT or MADIT II.

The results apply to a SCD-HeFT population.

Outcomes analyses based on QRS duration as well as patient NYHA class, LVEF, and beta blocker use hinted at differences in the ICD survival benefit in SCD-HeFT. However, Bardy emphasized in his presentation that "all subgroup analyses are to be interpreted conservatively." At a press conference following his formal presentation, he backed away several times from attaching any importance to the possible subgroup differences. And in a talk with heartwire , he said the MADIT II results are "irrelevant" to SCD-HeFT. "The results apply to a SCD-HeFT population."

SCD-HeFT was sponsored by Medtronic, Inc (Minneapolis, MN), Wyeth Pharmaceuticals (Madison, NJ), and the National Heart, Lung, and Blood Institute (Bethesda, MD).

Three- and five-year all-cause mortality by treatment group in SCD-HeFT

All-cause mortality




3 years (%)

17.1 24.0 22.3

5 years (%)

28.9 34.1 35.8

Relative risk for all-cause mortality for ICD recipients in SCD-HeFT as compared with placebo: Total population and subgroups, median follow-up 45.5 months


Number (ICD+control)

Hazard ratio

97.5% CI

All patients

1676 0.77* 0.62-0.96

NYHA class 2

1160 0.54 0.40-0.74

NYHA class 3

516 1.16 0.84-1.61

Ischemic HF

884 0.79 0.60-1.04

Nonischemic HF

794 0.73 0.50-1.04

LVEF <30%

1390 0.73 0.57-0.92

LVEF >30%

285 1.08 0.57-2.07

QRS <120 ms

977 0.84 0.62-1.14

QRS >120 ms

699 0.67 0.49-0.93

On beta blockers

1157 0.68 0.51-0.91

Not on beta blockers

519 0.92 0.65-1.30


Prevalence of standard medical therapy use in SCD-HeFT


Baseline rate (%)

Rate at last follow-up (%)

ACE inhibitors

85 72

ACE Inhibitors or angiotensin receptor blockers

96 87

Beta blockers

69 78


38 47


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