To evaluate the effect and safety of proproteinconvertase subtilisin-kexin type 9 (PCSK9) inhibitor in-hospital use on bloodlipid level in the acute coronary syndrome (ACS) patients.

We searched the PubMed, MEDLINE, Web of Science, Ovid and Cochrane Library electronic databases through July 2023 to identify randomized controlled trials (RCTs) and cohort studies using PCSK9 inhibitors (Evolocumab and Alirocumab) during ACS hospitalization. Then we compared thePCSK9 inhibitor group with a placebo or a blank control group with the same background of lipid-lowering therapy. Two reviewers independently screened the literature, extracted data, and evaluated the risk of bias for the included studies. Stata 17.0 software was used to analyze the changes in overall lipids from baseline and the adverse event rates.

A total of 15 studies enrolling 3891 patients with ACS were eligible, including 10 randomized controlled trials (n = 1406) and 5cohort studies (n = 2485). Treatment with PCSK9 inhibitors showed a greater reduction in low-density lipoprotein cholesterol (LDLC) (SMD=1.46, 95% CI:1.16-1.76, P<0.01). Cumulative meta of follow-up time showed that the degree of LDLC reduction stabilized after 12 weeks (SMD=1.42 at 12 weeks, 95% CI:1.06-1.79, P<0.01), and thus PCSK9 inhibitors dramatically decreased LDLC levels in comparison to controls at both ≤12 weeks and 12–72 weeks. The LDLC level with PCSK9 inhibitors reached the recommended standards of AHA/ACC(≤1.8mmol/l) and ESC(≤1.4mmol/l) were 95% and 80% respectively, significantly higher than those of the control group (58% and 22%). PCSK9 inhibitor can also reduce the total cholesterol, triglyceride, apolipoprotein B, and lipoprotein (a), while increase the high-density lipoprotein cholesterol, but it has no statistical significance in reducing apolipoprotein A1. Compared with placebo or blank control, the addition of PCSK9 inhibitor did not increase the occurrence of adverse events (RR =-0.01,95% CI:-0.19-0.18, P = 0.95) and serious adverse events (RR =-0.03, 95% CI:-0.48-0.43, P=0.91).

Lipid management is a crucial component of secondary prevention in patients with ACS.  PCSK9 inhibitor in-hospital use can significantly improve the blood lipid level of ACS patients, and increase the target LDLC attainment rate, with satisfactory safety and good tolerance. It is imperative to utilize PCSK9 inhibitors in reducing LDLC earlier, quicker, and more aggressively in the treatment of early ACS, although further clinical trial evidence is still required to confirm their benefits in preventing cardiovascular events.