Improvements in long-term mortality after myocardial infarction and increased use of cardiovascular drugs after discharge: a 10-year trend analysis

Abstract

Objectives: We sought to assess the relationship between increasing use of cardiovascular medications and trends in long-term prognosis after myocardial infarction (MI) in the elderly.

Background: During the past decade, statins, beta-blockers (BBs), angiotensin-converting enzyme inhibitors (ACEIs), and angiotensin-II receptor blockers (ARBs) have been increasingly used after MI. However, little is known about the relationship between increasing use of these medications and improvements in prognosis after MI.

Methods: Using data from pharmacy assistance programs and Medicare in 2 states (1995 to 2004), we identified patients with MI who survived >or=30 days after discharge. We assessed age, gender, race, comorbidities, and coronary interventions during the MI hospitalization and recorded filled prescriptions for statins, BBs, ACEIs/ARBs, or antiplatelet agents within 30 days after discharge. All patients were tracked until they died or until the end of the eligibility/study period. We built multivariate Cox proportional hazards regression models to assess trends in long-term mortality and the contribution to increasing medication use after MI.

Results: Of 21,484 patients identified, 12,142 died during 74,982 person-years of follow-up. After adjusting for demographics and comorbidities, we found that mortality after MI decreased significantly from 1995 to 2004 (hazard ratio for annual trend 0.97; 95% confidence interval 0.97 to 0.98), a 3% reduction in mortality each year. Adjusting for the use of statins, BBs, ACEIs/ARBs, and antiplatelet drugs after discharge completely eliminated the association between time trend and mortality (hazard ratio 1.00; 95% confidence interval 0.99 to 1.01).

Conclusions: The observed improvement in long-term mortality in elderly patients with MI may be mainly due to increased use of cardiovascular medications after discharge.