Alirocumab cuts cardiovascular events regardless of sex, with a larger benefit at higher baseline Lp(a) in women, ODYSSEY OUTCOMES (J Clin Lipidol 2024)

Background: The ODYSSEY OUTCOMES trial (NCT01663402) compared the effects of the proprotein convertase subtilisin/kexin type 9 inhibitor alirocumab with placebo on major adverse cardiovascular events (MACE) in patients with recent acute coronary syndrome (ACS).

Objective: We assessed efficacy and safety of alirocumab versus placebo according to sex and lipoprotein(a) level.

Methods: This prespecified analysis compared the effects of alirocumab versus placebo on lipoproteins, MACE (coronary heart disease death, non-fatal myocardial infarction, fatal/non-fatal ischemic stroke, unstable angina requiring hospitalization), death, total cardiovascular events, and adverse events in 4762 women and 14,162 men followed for a median of 2.8 years. In post-hoc analysis, we evaluated total cardiovascular events according to sex, baseline lipoprotein(a), and treatment.

Results: Women were older, had higher baseline low-density lipoprotein cholesterol (LDL-C) levels (89.6 vs 85.3 mg/dL) and lipoprotein(a) (28.0 vs 19.3 mg/dL) and had more co-morbidities than men. At 4 months, alirocumab lowered LDL-C by 49.4 mg/dL in women and 54.0 mg/dL in men and lipoprotein(a) by 9.7 and 8.1 mg/dL, respectively (both p < 0.0001). Alirocumab reduced MACE, death, and total cardiovascular events similarly in both sexes. In the placebo group, lipoprotein(a) was a risk factor for total cardiovascular events in women and men. In both sexes, reduction of total cardiovascular events was greater at higher baseline lipoprotein(a), but this effect was more evident in women than men (pinteraction=0.08). Medication adherence and adverse event rates were similar in both sexes.

Conclusions: Alirocumab improves cardiovascular outcomes after ACS irrespective of sex. Reduction of total cardiovascular events was greater at higher baseline lipoprotein(a).