Alirocumab and Cardiovascular Outcomes in Patients With Previous Myocardial Infarction: Prespecified Subanalysis From ODYSSEY OUTCOMES

Background: After acute coronary syndrome (ACS), patients with a previous myocardial infarction (MI) may be at particularly high risk for major adverse cardiovascular events (MACE) and death. We studied the effects of the PCSK9 inhibitor alirocumab in patients with recent ACS according to previous history of MI. Methods: The ODYSSEY OUTCOMES trial compared alirocumab with placebo, beginning 1 to 12 months after ACS with median 2.8-year follow-up. The primary MACE outcome comprised death from coronary heart disease, nonfatal MI, fatal or nonfatal ischemic stroke, and hospitalization for unstable angina. Of 18,924 patients, 3633 (19.2%) had previous MI. Results: Patients with previous MI were older, more likely male, with more cardiovascular risk factors and previous events. With placebo, 4-year risks of MACE and death were higher among those with vs without previous MI (20.5% vs 8.9%, P < 0.001; 7.4% vs 3.4%, P < 0.001, respectively). Alirocumab reduced the risk of events regardless of the presence or absence of a history of MI (MACE, adjusted hazard ratio [aHR] 0.90, 95% confidence interval [CI], 0.78-1.05 vs 0.82, 0.73-0.92; P_interaction = 0.34; death, aHR 0.84; 95% CI, 0.64-1.08 vs 0.87, 0.72-1.05; P_interaction = 0.81). Estimated absolute risk reductions with alirocumab were numerically greater with vs without previous MI (MACE, 1.91% vs 1.42%; death, 1.35% vs 0.41%). Conclusions: A previous history of MI places patients with recent ACS at high risk for recurrent MACE and death. Alirocumab reduced the relative risks of these events consistently in patients with or without previous MI but with numerically greater absolute benefit in the former subgroup.