In-hospital initiation of a PCSK9 inhibitor in patients with acute coronary syndrome: A systematic review and meta-analysis of randomized controlled trials

Background: Proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors have been shown to be effective and safe in patients with stable angina and previous myocardial infarction. However, evidence for initiating their use in patients hospitalized with acute coronary syndrome (ACS) is limited. This systematic review and meta-analysis was performed to provide more clinical evidence. Methods: PubMed, Embase, OVID, Cochrane Library and ClinicalTrials.gov were systematically searched for eligible randomized controlled trials up to March 20, 2023. The risk ratios, standardized mean differences and 95% confidence intervals were calculated for primary and secondary outcomes. The bias risk of the included studies was assessed using the Cochrane RoB 2 criteria. Results: About 8 randomized controlled trials involving 1255 inpatients with ACS were included. PCSK9 inhibitor treatment significantly reduced low-density lipoprotein cholesterol (LDL-C) (SMD -1.28, 95% CI -1.76 to -0.8, P = .001), triglycerides (TG) (SMD -0.93, 95% CI -1.82 to -0.05, P = .03), total cholesterol (SMD -1.36, 95% CI -2.01 to -0.71, P = .001), and apolipoprotein B (Apo B) (SMD -0.81, 95% CI -1.09 to -0.52, P = .001) within approximately 1 month. PCSK9 inhibitor treatment significantly reduced the total atheroma volume (TAV) (SMD -0.33, 95% CI -0.59 to -0.07, P = .012). It also significantly increased minimum fibrous cap thickness (FCT) (SMD 0.41, 95% CI 0.22-0.59, P = .001) in long-term follow-up (>6 months). PCSK9 inhibitor treatment significantly reduced the risk of readmission for unstable angina (RR 0.32, 95% CI 0.12-0.91, P = .032) in short-term follow-up (<6 months). There were no significant differences in all-cause mortality, cardiovascular death, myocardial infarction, ischemic stroke, coronary revascularization or heart failure. Only nasopharyngitis (RR 1.71, 95% CI 1.01-2.91, P = .047) adverse events were significantly observed in the PCSK9 inhibitor group. Conclusion: Application of a PCSK9 inhibitor in hospitalized patients with ACS reduced lipid profiles and plaque burdens and was well tolerated with few adverse events.