Impact of combined secondary prevention therapy after myocardial infarction: Data from a nationwide French registry

Background Several classes of medications improve survival in patients with coronary artery disease. Whether these medications, as used in the real world, have additive efficacy remains speculative. Objectives To assess whether patients discharged on combined secondary prevention medications after acute myocardial infarction (AMI) have improved 1-year survival, compared with the action of any single class of medications. Design and setting Nationwide registry of consecutive patients admitted to intensive care units for AMI in November 2000 in France. Multivariate Cox regression analysis, including a propensity score for the prescription of combined therapy, was used. Results Of the 2119 patients discharged alive, 1095 (52%) were prescribed a combination of antiplatelet agents, β-blockers, and statins (triple therapy), of whom 567 (27%) also received angiotensin-converting enzyme inhibitors (quadruple therapy) and 528 (25%) did not. One-year survival was 97% in patients receiving triple combination therapy versus 88% in those who received either none, 1, or 2 of these medications (P < .0001). After multivariate adjustment including the propensity score, the hazard ratio for 1-year mortality in patients with triple combination therapy was 0.52 (95% CI 0.33-0.81). In patients with ejection fraction ≤35%, β-blockers and angiotensin-converting enzyme inhibitors were independent predictors of survival, and combination therapy had no additional prognostic value. Conclusions Compared with the prescription of any single class of secondary prevention medications, combination therapy offers additional protection in patients with AMI.