Psychosocial predictors of mortality in the Cardiac Arrhythmia Suppression Trial-1 (CAST-1).

Author(s): Gorkin L, Schron EB, Brooks MM, Wiklund I, Kellen J, Verter J, Schoenberger JA, Pawitan Y, Morris M, Shumaker S

Affiliation(s): Institute for Behavioral Medicine, Providence, Rhode Island 02920.

Publication date & source: 1993-02-01, Am J Cardiol., 71(4):263-7.

Publication type: Clinical Trial; Randomized Controlled Trial

Psychosocial variables predict the recurrence of clinical events in symptomatic patients, controlling for measures of disease severity. The Cardiac Arrhythmia Suppression Trial-1, a pharmacologic test of the arrhythmia suppression and mortality hypothesis among postmyocardial infarction patients, allowed a prospective test of the relationship of distress, perceived support, social interaction, life stress, and other variables, to mortality, adjusting statistically for ejection fraction, arrhythmia rates, and other known risk factors for coronary heart disease. Results indicated that the treatment medications, encainide and flecainide, were powerful predictors of mortality. Although the psychosocial variables were significant as univariate predictors, these variables were not significant as predictors in a multivariate model that included drug treatment. When the data analysis was restricted to patients randomized to placebo, thereby eliminating the antiarrhythmic drug effect, the level of perceived social support was a significant multivariate predictor of mortality, adjusting for measures of disease severity. The adjusted hazards ratio for a 1-point decrease in the perceived support score is equal to 1.46, based on the multivariate model.