Utility of Beta‐Blockade Treatment for Older Postinfarction Patients

Abstract

The prevalence of myocardial infarction (MI) in older people 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 years of age remains less clear. We hypothesized that use of beta-blockers after MI in older adults would improve clinical outcomes. Retrospective cohort study. A community-based, tertiary-care teaching hospital. A total of 1011 consecutive MI patients aged 60 to 89 were admitted to Boston's Beth Israel Hospital between January 1988 and September 1989 and were screened for this study. One hundred eighteen patients met eligibility criteria, of whom 76 received metoprolol, > or = 25 mg/day for at least 5 days after their MI. Forty-two age and clinically matched patients were similarly suitable for beta-blocker therapy, but it was omitted by their physicians during and after hospitalization. The latter group served as controls. Mortality, reinfarction, and subsequent hospital admissions were measured. MI patients aged 60 to 89 years who were treated with metoprolol had an age-adjusted mortality reduction of 76% (RR 0.24; P < .001; 95% CI 0.11-0.54). Multivariate logistic regression analysis showed a 12% mortality reduction (95% CI 0.75-1.00) among older MI patients, attributable to metoprolol therapy. Reinfarction rates were unchanged in patients receiving metoprolol therapy, and subsequent rehospitalizations were significantly increased among the metoprolol patients. Use of metoprolol significantly reduced mortality in older MI patients. The fact that metoprolol-treated patients had neither reduced reinfarctions or rehospitalizations may relate to methologic limitations of this study. The mortality data support the hypothesis that older patients benefit from postinfarction beta-blockade.