- Unstable angina, myocardial infarction or cardiac death. Myocardial infarction is defined as a cardiac event requiring admission to the hospital with the development of cardiac enzyme level elevation. Unstable angina is defined by accelerating anginal symptoms with or without ischemic electrocardiographic changes requiring hospital admission and coronary revascularization. Death will be attributed to a cardiac origin in the case of documented significant arrhythmia and/or cardiac arrest, congestive heart failure, or myocardial infarction. Moreover, any unexplained death that occurs suddenly out of the hospital will be ascribed a cardiac cause.