Medical research has shown that patients who present with an acute "heart attack" (myocardial infarction), are at increased risk for developing irregularity in their heart rhythm, called an "arrhythmia". The damaged (necrosed), heart muscle is believed to be the "substrate" which generates an ectopic rhythm. A sustained, complex ventricular arrhythmia can turn "malignant", cause a rapid, ineffective and chaotic heart rhythm, and lead to cardiac standstill, also called "sudden cardiac death". When the infarction has been extensive enough to moderately compromise overall left heart contractility (pump function), the risk for sudden cardiac death further increases.

Over 50% of all cardiovascular deaths are sudden cardiac deaths (SCD). Nearly 300,000 – 400,000 SCDs are reported in the United States annually. Thirty five per cent of these are in the convalescent phase of acute myocardial infarction, and 25% are in patients with significantly compromised left ventricular function (global LVEF <35%).

[Azimilide Post Infarct Survival Evaluation Trial]. This is a double-blind, placebo-controlled, study to determine the effect of 75 mg or 100 mg of orally administered Azimilide (a new Class III anti-arrhythmic agent) versus placebo on survival in recent post-myocardial infarction patients identified to be "high risk" for sudden cardiac death. Azimilide protects the heart from lethal arrhythmias by eliminating or lessening the severity of complex arrhythmias, that can lead to atrial fibrillation (rapid, chaotic atrial rhythm), ventricular fibrillation (rapid, chaotic ventricular rhythm), and SCD. Patients will be followed for one year after the myocardial infarction. Sponsor: Procter and Gamble Pharmaceuticals, Inc., 1997 to present.