Sex Differences in Cardiovascular Outcomes and Cholesterol-Lowering Efficacy of PCSK9 Inhibitors: Systematic Review and Meta-Analysis

Background: Guideline-recommended low-density lipoprotein cholesterol (LDL-C) thresholds are often not achieved in women. The proprotein convertase subtilisin/kexin type-9 inhibitor (PCSK9i) monoclonal antibodies can help further reduce LDL-C and major adverse cardiovascular events (MACE) although differences in efficacy by sex and type are less understood.

Objectives: The authors sought to determine if there are differences in the efficacy of LDL-C lowering and reduction in the risk of MACE by sex and type of PCSK9i.

Methods: A comprehensive literature search was done through October 17, 2022, for published trials comparing PCSK9i vs control. Outcomes assessed were LDL-C reduction and incidence of MACE following the use of PCSK9i vs placebo, stratified by sex and type of PCSK9i used.

Results: We identified 16 trials with 54,996 adults, and 15,143 (27.5%) of them were female. PCSK9i significantly reduced MACE compared to placebo in both women (HR: 0.86, 95% CI: 0.74-0.97, P < 0.001) and men (HR: 0.85, 95% CI: 0.79-0.91, P < 0.001) with no significant sex difference (MD -0.01, 95% CI: -0.14 to -0.13, P = 0.930). PCSK9i also significantly reduced LDL-C levels in both sexes at 12 weeks (females: MD -62.57, 95% CI: -70.24 to -54.91, P < 0.001; males: MD -66.19, 95% CI: -72.03 to -60.34, P < 0.001) and 24 weeks (females: MD -47.52, 95% CI: -52.94 to -42.09, P < 0.001; males: MD -54.07, 95% CI: -59.46 to -48.68, P < 0.001). Significant sex difference was seen in the LDL reduction of PCSK9i for both 12 weeks (males vs females: MD -4.55, 95% CI: -7.34 to -1.75, P < 0.01) and 24 weeks (males vs females: MD -7.11, 95% CI: -9.99 to -4.23, P < 0.001).

Conclusions: The use of PCSK9i results in significant LDL-C and MACE reduction in both males and females. While there is no significant sex difference in MACE reduction, LDL-C reduction is greater in males than in females. Our data support the equal use of PCSK9i in all eligible patients, regardless of sex.