Current concepts and animal models of sudden cardiac death for drug development

Sudden cardiac death (SCD) or sudden coronary death, occurring in patients with unstable angina (angina at rest), myocardial ischemia with or without myocardial infarction (MI), and congestive heart failure (CHF), emerges as one of the most important challenges in cardiovascular medicine at present. Of the 1.5 million cases of myocardial infarction that occur each year in the U.S., about 540,000 patients will die and more than 300,000 of these will die before they reach a hospital, mostly due to ventricular fibrillation (VF) and/or SCD. About 4.8 million people alive in the U.S. have a history of myocardial infarction, angina pectoris, or both and are prime candidates for SCD. About 3 million people in the U.S. have congestive heart failure (CHF) and about 400,000 new cases are reported each year. One year mortality due to CHF is 33–58% and about 45% of the deaths are sudden. These patients were not those who had deleterious hemodynamic parameters whose demise could be predicted; they were those that died suddenly and unexpectedly of VF. Current pharmacological intervention in patients with a documented myocardial infarction with marketed antiarrhythmic agents has not reduced the overall mortality of SCD significantly. This suggests that an efficacious antiarrhythmic/antifibrillatory agent for the prevention of SCD does not exist at present and that there is an urgent need for such an agent.