(October 7, 2009 - Insidermedicine)

 Treatment with an implantable cardioverter-defibrillator (ICD) is no better than medical therapy for improving survival among patients suffering from a myocardial infarction (MI), according to research published in the latest issue of the New England Journal of Medicine.

According to the American College of Cardiology and American Heart Association, placement of an implantable ICD at least 40 days post-MI is reasonable in patients with ischemic cardiomyopathy who:

•    Have an LVEF of 30% or less

•    Are New York Heart Association (NYHA) functional class I on chronic optimal medical therapy

•    Have reasonable expectation of survival with a good functional status for more than 1 year.

Researchers representing the IRIS investigators randomized 898 patients to treatment with an ICD or to medical therapy alone during the 5 to 31 days following an MI. All patients had a reduced left ventricular ejection fraction (LVEF) with a heart rate of 90 bpm or more on the first available electrocardiogram (ECG), nonsustained ventricular tachycardia (VT) during Holter monitoring, or all these clinical features.

During a mean follow-up period of 37 months, nearly one quarter of patients in each group died. While overall mortality was similar for both groups, sudden cardiac deaths occurred less frequently in the ICD group, with a hazard ratio (HR) of 0.55. The number of nonsudden cardiac deaths was higher in the ICD group, however, for an HR of 1.92.

Today's research demonstrates that ICD is not effective for reducing the risk of mortality in high-risk patients who suffer an MI.