Medication, reperfusion therapy and survival in a community-based setting of hospitalised myocardial infarction.

OBJECTIVE: To examine the survival benefit of multiple medical therapies in a large, community-based population of validated myocardial infarction (MI) events.

DESIGN: Retrospective observational cohort study.

SETTING: Population-based sample of 30 986 definite or probable MIs in residents of four US communities aged 35-74 years randomly sampled between 1987 and 2008 as part of the Atherosclerosis Risk in Communities Surveillance Study.

INTERVENTIONS: None.

MAIN OUTCOME MEASURES: All-cause mortality 30, 90 and 365 days after discharge.

RESULTS: We used unadjusted and propensity score (PS) adjusted models to examine the relationship between medical therapy use and mortality. In unadjusted models, each medication and procedure was inversely associated with 30-day mortality. After PS adjustment, the crude survival benefits were attenuated for all therapies except for intravenous tissue plasminogen activator therapy (IV-tPA) and stent use. After inclusion of other therapies received during the event in regression models, risk ratio effect estimates (RR; (95% CI)) were attenuated for aspirin (0.66; (0.58 to 0.76) to 0.91 (0.80 to 1.03)), non-aspirin antiplatelets (0.74; (0.59 to 0.92) to 0.92 (0.72 to 1.18)), IV-tPA (0.50; (0.41 to 0.62) to 0.65 (0.52 to 0.80)) and stents (0.53 (0.40 to 0.69) to 0.68 (0.49 to 0.94)). Effect estimates remained stable for all other therapies and were similar for 90- and 365-day mortality endpoints.

CONCLUSIONS: We observed inverse associations between receipt of six medications and procedures for MI and all-cause mortality at 30, 90 and 365 days after adjustment for PS. The mortality benefits observed in this population-based setting are consistent with those reported in clinical trials.