PCSK-9 inhibitors vs. ezetimibe for secondary prevention: utilization disparities and clinical outcomes

Background Statins are the cornerstone of secondary prevention after acute myocardial infarction (AMI). However, additional lipid-lowering therapy may be required to achieve guideline-recommended lipoprotein levels. PCSK-9 inhibitors and ezetimibe are adjunct options, with PCSK-9 inhibitors demonstrating superior lipid-lowering effects. Concerns exist regarding disparities in PCSK-9 inhibitor utilization due to cost. Purpose This study examines racial disparities and clinical outcomes associated with PCSK-9 inhibitor use as an adjunct to statins, using a nationwide multi-center database. Methods This retrospective cohort study utilized TriNetX, an EHR-based data platform from large academic medical centers across the United States. Patients who experienced an AMI between January 2015 and January 2022 were identified using ICD-10 codes. Two cohorts were defined based on lipid-lowering therapies: one receiving statins plus PCSK9 inhibitors and the other receiving statins plus ezetimibe. The cohorts were compared for sex and racial differences, followed by a propensity-score-matched analysis. The primary outcome was the 3-year incidence of major adverse cardiovascular event (MACE), defined as all-cause mortality, AMI, and stroke. Results PCSK-9 inhibitor use was higher among White patients (74.0% vs. 67.4%, p < 0.0001) and lower among Black (9.2% vs. 12.6%, p < 0.0001) and Asian patients (2.9% vs. 5.7%, p < 0.0001). PCSK-9 inhibitor therapy was associated with a lower 3-year incidence of MACE compared to ezetimibe (10.1% vs. 17.7%; HR 0.57 [0.43, 0.74]). Conclusions White patients were more likely to receive PCSK-9 inhibitors than Black and Asian patients. PCSK-9 inhibitors demonstrated superior MACE reduction compared to ezetimibe when used alongside statins. Further research is needed to confirm these findings and address disparities in PCSK-9 inhibitor utilization.