Effect of Preoperative Administration of Proprotein Convertase Subtilisin/Kexin Type 9 Inhibitor on Carotid Artery Stenting.

Background: Perioperative embolic stroke is one of the most serious complications during carotid artery stenting (CAS). Proprotein convertase subtilisin/kexin type 9 inhibitor (PCSK9i) is a low-density lipoprotein-lowering drug that inhibits proprotein convertase subtilisin/kexin type 9, which normally binds to the low-density lipoprotein cholesterol (LDL-C) receptor. Its combination with statin significantly decreases LDL-C levels. PCSK9i is expected to achieve lower LDL-C levels than single use of statin. This study aimed to investigate whether perioperative PCSK9i administration stabilizes carotid artery plaque and reduces perioperative complications of CAS.

Methods: Nine patients with symptomatic stenosis (North American Symptomatic Carotid Endarterectomy Trial [NASCET] 50%) or asymptomatic stenosis (NASCET ≥ 80%) were included. PCSK9i was administered at least twice (once in 2 weeks) in the outpatient clinic before CAS. Perioperative complications; results from blood tests, magnetic resonance imaging (MRI), magnetic resonance angiography, and carotid ultrasonography (US); and modified Rankin scale score at discharge were assessed.

Results: High intensity on diffusion-weighted imaging was not observed in 8 patients. Changes in carotid plaque characteristics were found with MRI and/or carotid US in 7 patients. The plaque to muscle ratio decreased in 3 patients. The carotid plaque became hyperechoic in 2 patients, and the fibrous cap was seen more clearly on carotid US. Two patients had findings of stabilized plaque on MRI and carotid US, which indicates that plaque transformation was more stable.

Conclusions: Lowering LDL-C level could reduce ischemic complications, and low LDL-C level affects plaque stability and antithrombus formation. PCSK9i can possibly stabilize carotid plaque and reduce perioperative complications of CAS.