HEALTH OUTCOMES ASSOCIATED WITH BETA-BLOCKER AND DILTIAZEM TREATMENT OF UNSTABLE ANGINA

Objective. We compared long-term health outcomes associated with beta adrenergic blocking agents and diltiazem treatment for unstable angina . Background. No long-term data have been published comparing these tw o antianginal treatments in this setting. Methods. Eligible veterans w ere discharged from the Veterans Affairs Puget Sound Health Care Syste m (VAPSHCS), Seattle Division, between October 1989 and September 1995 with an unstable angina diagnosis and were prescribed monotherapy bet a-blocker or diltiazem treatment at discharge, Medication data were co llected from medical records and computerized VAPSHCS outpatient pharm acy files, Follow-up death and coronary artery disease rehospitalizati on data were collected through 1996. Proportional hazards regression c ompared survival among diltiazem and beta-blocker users, controlling f or patient characteristics with propensity scores. Results. TWO hundre d forty-seven veterans (24% on beta-blockers, 76% on diltiazem) were i ncluded in this study. There were 54 (22%) deaths during an average fo llow-up of 51 months. After propensity score adjustment, there was no difference in risk of death comparing diltiazem to beta-blocker treatm ent (hazards ratios [HR] 1.1; 95% confidence interval [CI] 0.49 to 2.4 ). Among Washington residents (n = 207), there were 146 (71%) coronary artery disease rehospitalizations or deaths during follow-up. After a djustment, there was a nonsignificant increase in risk of rehospitaliz ation or death associated with diltiazem use (HR 1.4; 95% CI 0.80 to 2 .4). For both analyses, similar risks were found among veterans withou t relative contraindications to beta blockers. Conclusions. We found n o survival benefit of diltiazem over beta-blocker treatment for unstab le angina in this cohort of veterans. (C) 1998 by the American College of Cardiology.