HRS: ICD therapy shows benefit at long-term follow-up
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SCD-HeFT, which began in 1997, remains the only placebo-controlled ICD trial and initial findings showed that ICD therapy provided a 23 percent survival advantage when compared with amiodarone treatment or placebo, according Jeanne E. Poole, MD, of the University of Washington in Seattle, one of the study authors. While the initial results were based on a median follow-up of 45.5 months, the long term follow-up results were based on a median follow-up of 11 years.
Patients from SCD-HeFT were randomized to receive amiodarone, a placebo or a single lead shock-only ICD therapy. Patients were grouped based on whether the heart failure was ischemic or non-ischemic, and also by whether the heart failure was Class II or Class III according to New York Heart Association (NYHA) classifications.
Mortality data for the long term follow-up were available on 2,291 (91 percent) of the original patients enrolled in SCD-HeFT, though data were limited on long term use of amiodarone and new ICD implantations.
ICD therapy provided an absolute risk reduction of 5 percent compared with placebo. When looking at the individual patient subgroups, NYHA Class II patients randomized to ICD therapy demonstrated benefit over placebo, with a hazard ratio of 0.76. There was no significant reduction in mortality for NYHA Class III patients.
“Consistent with the original trial results, ICD therapy is most beneficial in less ill, NYHA Class II patients, whereas ICD therapy does not appear to benefit patients who were considered NYHA Class III at enrollment into SCD-HeFT,” said Poole.
Patients with ischemic heart failure also demonstrated a reduction in mortality with ICD therapy. Patients with non-ischemic heart disease, despite initially showing a reduction, saw their benefit reduce over time, with a hazard ratio at long term follow-up of 0.97.