Effect of Proprotein Convertase Subtilisin/Kexin Type 9 Inhibitors on Plasma Ceramide Levels

Proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors are novel drugs that provide striking lowering of low-density lipoprotein cholesterol (LDL-C) when added to maximum tolerated therapy in patients with hypercholesterolemia. Ceramides, novel cardiac risk markers, have been associated with increased cardiovascular mortality, independent of traditional cardiovascular risk factors. The Ceramide Risk Score (CRS) predicts the likelihood of adverse cardiovascular events within 1 to 3 years in patients with coronary artery disease. The effect of PCSK9 inhibition on plasma ceramides is not well known. The study examines the effect of PCSK9 inhibitors on plasma ceramides and CRS in patients with clinical indication for this therapy. Retrospective chart review of consecutive patients with hypercholesterolemia on PCSK9 inhibitors was conducted (n = 24; Mayo Clinic 2015 to 2018). Plasma ceramides were measured before the initiation of PCSK9 inhibitors and 2 to 12 months after treatment. CRS was calculated before and after therapy based on individual plasma concentrations of 4 ceramides. Treatment with PCSK9 inhibitors was associated with significant reduction in mean CRS and individual ceramides levels (p <0.0001). CRS significantly improved with PCSK9 therapy. PCSK9 inhibitors significantly decreased LDL-C levels by 63% (p <0.0001). The absolute reduction in CRS did not correlate with the absolute reduction in LDL-C (r = 0.31; confidence interval -0.10 to 0.64), indicating that CRS may evaluate a different pathway for risk reduction beyond LDL-C lowering. In conclusion, treatment with PCSK9 inhibitors is associated with significant reduction in CRS and distinct ceramide levels.