NATIONAL USE AND EFFECTIVENESS OF BETA-BLOCKERS FOR THE TREATMENT OF ELDERLY PATIENTS AFTER ACUTE MYOCARDIAL-INFARCTION - NATIONAL COOPERATIVE CARDIOVASCULAR PROJECT

Context. - Despite the importance of beta-blockers for secondary preve ntion after acute myocardial infarction (AMI), several studies have su ggested that they are substantially underutilized, particularly in old er patients. Objectives. - To describe the contemporary national patte rn of beta-blocker prescription at hospital discharge among patients a ged 65 years or older with an AMI, to identify the most important pred ictors of the prescribed use of beta-blockers at discharge, and to det ermine the independent association between beta-blockers at discharge and mortality in clinical practice. Design. - Retrospective cohort stu dy using data created from medical charts and administrative files. Se tting. - Acute care nongovernmental hospitals in the United States. Pa tients. - National cohort of 115015 eligible patients aged 65 years or older who survived hospitalization with a confirmed AMI in 1994 or 19 95. Main Outcome Measures. - beta-Blocker as a discharge medication an d mortality in the year after discharge. Results. - Among the 45308 pa tients without contraindications to beta-blockers, 22665 (50.0%) had a beta-blocker as a discharge medication. There was significant variati on by state, ranging from 30.3% to 77.1%. Of the 36795 patients who we re not receiving beta-blocker therapy on admission, 16006 (43.5%) had therapy initiated on or before discharge. Demographic and clinical var iables explained relatively little of the variation in the initiation of beta-blocker therapy. The prescribed use of calcium channel blocker s at discharge had a strong negative association with the use of beta- blockers (odds ratio [OR] of beta-blocker use, 0.25; 95% confidence in terval [CI], 0.24-0.26). The New England region had significantly high er use of beta-blocker therapy than the rest of the country. Compared with cardiologists, internists had similar rates (OR, 0.94; 95% CI, 0. 90-1.00) and general and family practice physicians had lower rates (O R, 0.78; 95% CI, 0.73-0.83), After adjusting for potential confounders , beta-blockers were associated with a 14% lower risk of mortality at 1 year after discharge. The association with lower mortality was prese nt in subgroups stratified by age, sex, and left ventricular ejection fraction. Conclusions. - Many ideal patients for beta-blocker therapy are not prescribed these drugs at discharge following AMI. The clinica l and demographic characteristics of the patients do not explain much of the variation in the treatment pattern. Geographic factors and phys ician specialty are independently associated with the decision to use beta-blockers, Elderly patients who are prescribed beta-blockers at di scharge have a better survival rate, consistent with the findings of r andomized controlled trials of younger and lower-risk populations.