Nl. Smith et al., HEALTH OUTCOMES ASSOCIATED WITH BETA-BLOCKER AND DILTIAZEM TREATMENT OF UNSTABLE ANGINA, Journal of the American College of Cardiology, 32(5), 1998, pp. 1305-1311
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.