Meta-Analysis: ICDs Improve Survival in Ischemic and Nonischemic Cardiomyopathy

By Amy Orciari Herman

Edited by David G. Fairchild, MD, MPH, and Jaye Elizabeth Hefner, MD

Implantable cardioverter-defibrillators (ICDs) improve survival over conventional care in patients with either ischemic or nonischemic cardiomyopathy, finds a meta-analysis in the Annals of Internal Medicine. Last year's DANISH trial questioned ICDs' benefits in patients with nonischemic disease.

Researchers examined data from 11 randomized trials comparing ICD therapy with conventional care (e.g., contemporary medical therapy, antiarrhythmic therapy) for primary prevention in some 8700 adults with heart failure and reduced ejection fraction. Among the findings, over roughly 3 years' follow-up:

• All-cause mortality was significantly lower with ICDs than with conventional care in patients with nonischemic cardiomyopathy (20% vs. 24%), and nonsignificantly lower with ICDs in those with ischemic disease (22% vs. 30%).

• Sudden death was nonsignificantly lower with ICDs in patients with nonischemic cardiomyopathy (3% vs. 7%), and significantly lower with ICDs in those with ischemic disease (5% vs. 15%).

• ICD therapy's survival benefits were seen regardless of patient age, sex, symptoms, systolic function, and QRS duration.

Dr. Mark Link of NEJM Journal Watch Cardiology commented: "This meta-analysis shows that our current indications for ICD implantation should not be altered by the DANISH study. But we should use the art of medicine wisely; not all patients with a reduced ejection fraction benefit from ICDs."