Effectiveness and safety of proprotein convertase subtilisin/kexin type 9 inhibitors in patients with familial hypercholesterolemia. Our experience in implementing the drug program of the Polish National Health Fund

Introduction
Heterozygous familial hypercholesterolemia (FH) is characterized by an elevated plasma low-density lipoprotein cholesterol (LDL-C) concentration despite intensive statin and ezetimibe therapy, which significantly increases the cardiovascular risk. Aim: The study evaluated the efficacy and safety of proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors, alirocumab and evolocumab, in reducing lipids in patients with FH.

Material and methods
This was a single-center analysis of 22 patients diagnosed with FH treated with the PCSK9 inhibitors under the drug program of the National Health Fund. The follow-up interviews and laboratory tests were performed at baseline (22 patients), 3 months (22 patients) and 15 months (9 patients) after the first dose of PCSK9 inhibitors.

Results
The mean (SD) baseline level of the total LDL-C fraction was 4.7 ±1.6 mmol/l in the whole group of patients and was significantly reduced after 3 and 15 months of PCSK9 inhibitors therapy to 1.7 ±1.6 and 1.6 ±1.1 mmol/l, respectively. The average percentage of reduction in LDL-C level was 64.9 ±23.7% after 3 months and 66.9 ±18.4% after 15 months. In comparison with baseline, a significant reduction in total cholesterol was observed at both time points (p <0.0002). There were no adverse cardiovascular events or significant growth in the level of alanine transaminase, creatinine, and creatine kinase throughout the study.

Conclusions
Patients with FH treated with PCSK9 inhibitors achieved a significant reduction of LDL-C and total cholesterol with the safety of this treatment in follow-up.