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

L Gorkin1, E B Schron, M M Brooks

  • 1Institute for Behavioral Medicine, Providence, Rhode Island 02920.

Insights

Psychosocial factors like social support may impact mortality risk in heart patients. However, antiarrhythmic drugs significantly predicted mortality in a major trial, overshadowing psychosocial effects.

Area of Science:

  • Cardiology
  • Psychosocial Medicine
  • Clinical Trials

Background:

  • Psychosocial variables are known to influence clinical event recurrence in symptomatic patients.
  • The Cardiac Arrhythmia Suppression Trial-1 (CAST-1) investigated the arrhythmia suppression and mortality hypothesis in post-myocardial infarction patients.

Purpose of the Study:

  • To prospectively assess the relationship between psychosocial variables (distress, perceived support, social interaction, life stress) and mortality.
  • To adjust for disease severity and known coronary heart disease risk factors.

Main Methods:

  • Analysis of data from the Cardiac Arrhythmia Suppression Trial-1.
  • Multivariate statistical modeling to assess predictors of mortality.
  • Stratified analysis comparing drug treatment groups and placebo.

Main Results:

  • Encainide and flecainide were identified as potent predictors of mortality.
  • Psychosocial variables were significant univariate predictors but not in multivariate models including drug treatment.
  • In the placebo group (without antiarrhythmic drugs), perceived social support emerged as a significant multivariate predictor of mortality.

Conclusions:

  • Antiarrhythmic drug treatment in CAST-1 strongly predicted mortality, masking psychosocial effects.
  • Perceived social support is a significant independent predictor of mortality in post-myocardial infarction patients not receiving suppressive antiarrhythmic drug therapy.