UTILITY OF BETA-BLOCKADE TREATMENT FOR OLDER POSTINFARCTION PATIENTS

OBJECTIVE: The prevalence of myocardial infarction (MI) in older peopl e is high. Whereas use of beta-blockers after MI is known to lower MI mortality in younger adults, its efficacy for adults more than 75 year s of age remains less clear. We hypothesized that use of beta-blockers after MI in older adults would improve clinical outcomes. DESIGN: Ret rospective cohort study. SETTING: A community-based, tertiary-care tea ching hospital. METHODS: A total of 1011 consecutive MI patients aged 60 to 89 were admitted to Boston's Beth Israel Hospital between Januar y 1988 and September 1989 and were screened for this study. One hundre d eighteen patients met eligibility criteria, of whom 76 received meto prolol, greater than or equal to 25 mg/day for at least 5 days after t heir MI. Forty-two age and clinically matched patients were similarly suitable for beta-blocker therapy, but it was omitted by their physici ans during and after hospitalization. The latter group served as contr ols. MEASUREMENTS: Mortality, reinfarction, and subsequent hospital ad missions were measured. RESULTS: MI patients aged 60 to 89 years who w ere treated with metoprolol had an age-adjusted mortality reduction of 76% (RR 0.24; P < .001; 95% CI 0.11-0.54). Multivariate logistic regr ession analysis showed a 12% mortality reduction (95% CI 0.75-1.00) am ong older MI patients, attributable to metoprolol therapy. Reinfarctio n rates were unchanged in patients receiving metoprolol therapy, and s ubsequent rehospitalizations were significantly increased among the me toprolol patients. CONCLUSIONS: Use of metoprolol significantly reduce d mortality in older MI patients. The fact that metoprolol-treated pat ients had neither reduced reinfarctions or rehospitalizations may rela te to methologic limitations of this study. The mortality data support the hypothesis that older patients benefit from postinfarction beta-b lockade.