Use of aspirin, beta-blockers, and lipid-lowering medications before recurrent acute myocardial infarction: missed opportunities for prevention?

Background: For patients who have had a previous myocardial infarction (MI), the use of aspirin, beta-blockers, and lipid-lowering agents reduces the risk of recurrent MI and death.
Objective: To examine trends in and determinants of receipt of these 3 medications before hospitalization for recurrent acute MI (AMI).
Methods: The study population consisted of 1710 patients with a previous history of MI hospitalized with a validated recurrent AMI in all hospitals in Worcester, Mass, during 1986, 1988, 1990, 1991, 1993, and 1995. Logistic regression analyses were used to assess the effect of demographic, clinical, and temporal factors on the receipt of aspirin, beta-blockers, and lipid-lowering medications before hospital admission for recurrent AMI.
Results: More than 47% of patients in each study year were not receiving each medication before admission, although significant increases in use were noted over time for aspirin (from 13.5% to 52.6%), beta-blockers (from 33.2% to 44.4%), and lipid-lowering medications (from 0.8% to 11.7%). In multivariate analyses, advancing age was associated with not receiving aspirin (odds ratio [OR], 0.67; 95% confidence interval [CI], 0.51-0.89), lipid-lowering medications (OR, 0.14; 95% CI, 0.08-0.25), and beta-blockers (OR, 0.75; 95% CI, 0.57-1.00), although this effect was of borderline significance for beta-blockers. Being a woman was associated with not receiving aspirin (OR, 0.78; 95% CI, 0.62-0.98) but was positively associated with receiving lipid-lowering medications (OR, 1.59; 95% CI, 1.04-2.43). Coexisting medical conditions and concurrent use of other cardiovascular medications were also associated with receipt of each medication.
Conclusion: Despite encouraging increases over time, the low absolute levels of receipt of medications shown to be efficacious in the long-term treatment of patients after an MI, and their variation by age and sex, suggest that substantial opportunities may exist to prevent recurrent AMIs through the increased use of aspirin, beta-blockers, and lipid-lowering medications.