Repeated In-Stent Restenosis Despite Aggressive Lipid Loweringby PCSK-9 Inhibitor Treatment: A Case Report

A 76-year-old woman with unstable angina underwent coronary stent implantation. At the same time, rosuvastatin therapy was started. However, she experienced repeated in-stent restenosis (ISR). Treatment with a proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitor along with rosuvastatin (5 mg/day) reduced plasma low-density lipoprotein cholesterol to 10 mg/dL, but failed to prevent further ISR. Eventually, an increase in the rosuvastatin dose to the permitted maximum of 20 mg/day succeeded in preventing further in-stent restenosis. Rather than using PCSK9 inhibitors, intensive statin treatment, using the maximum dose of statins, should be prioritized for the secondary prevention of coronary artery disease.