Psychosocial and physiological predictors of sudden cardiac death after healing of acute myocardial infarction.

Several major prospective studies that have examined the relation between type A behavior and cardiac mortality have failed to find an association. Since psychosocial factors have been implicated in the etiology of sudden cardiac death, it is possible that this association may emerge if sudden cardiac death is distinguished as an outcome distinct from other cardiac mortality. Predictors of sudden death and other cardiac outcomes were examined using data from the Recurrent Coronary Prevention Project, a 4.5-year prospective clinical trial of 1,012 postinfarction patients begun in San Francisco in 1978. A unique set of risk factors was found for the differing outcomes: sudden cardiac death had predominantly psychosocial predictors while nonsudden cardiac death and nonfatal recurrences were predominantly predicted by biologic factors. Type A behavior was an independent predictor of sudden, but not nonsudden, cardiac death in this population (p = 0.04). These results are the first demonstration of a direct relation between stress and sudden cardiac death in a large prospective clinical study, and provide insight into the failure of past prospective studies to find an association between type A behavior and cardiac mortality.