Chronic PCSK9 inhibitor therapy leads to sustained improvements in endothelial function, arterial stiffness, and microvascular function

Proprotein convertase subtilisin/kexin type 9 inhibitors (PCSK9i) effectively decrease low-density lipoprotein cholesterol (LDL-C) and reduce cardiovascular events in patients at very high cardiovascular risk. Recent short-term studies suggest a partially LDL-C independent beneficial effect of PCSK9 inhibitor (PCSK9i) therapy on endothelial function and arterial stiffness, whereas it is unknown if this effect persists and what the effect is on microcirculation. To investigate the effects of PCSK9i therapy on vascular parameters beyond its lipid lowering effect. In this prospective trial, 32 patients at very high cardiovascular risk and indication for PCSK9i therapy were included. Measurements were performed at baseline and after 6 months of PCSK9i treatment. Endothelial function was assessed as flow-mediated dilation (FMD). Arterial stiffness was measured as pulse wave velocity (PWV) and aortic augmentation index (AIx). Peripheral tissue oxygenation (StO2) as a marker of microvascular function was assessed at the distal extremities using near-infrared spectroscopy camera. Six months of PCSK9i therapy decreased LDL-C levels from 141 ± 54 to 60 ± 30 mg/dl (−56 ± 21 %, p