Effect of alirocumab on quantitative flow ratio and diameter stenosis in non-infarct related arteries from patients with acute myocardial infarction: a PACMAN-AMI randomized clinical trial substudy

Abstract Introduction Treating hypercholesterolemia with proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors on top of statins leads to plaque regression and stabilization. The effects of PCSK9 inhibitors on coronary physiology and angiographic diameter stenosis (DS%) are unknown. Quantitative Flow Ratio (QFR) is a novel method to assess coronary hemodynamics. Purpose We aimed to investigate the effects of the PCSK9 inhibitor alirocumab on QFR and 3D-Quantitative Coronary Angiography (3D-QCA) DS% in non-infarct-related arteries (non-IRA) among acute myocardial infarction (AMI) patients. Methods This was a pre-specified substudy of the PACMAN trial, a randomized, double-blind, placebo-controlled trial comparing alirocumab vs. placebo on top of high-intensity rosuvastatin among AMI patients. QFR and 3D-QCA were assessed at baseline and 1-year follow-up in any non-infarct related artery (non-IRA) with ≥2.0mm diameter and >25% 3D-QCA DS%. The pre-specified primary endpoint was the number of patients with mean QFR increase from baseline to follow-up, and the secondary endpoint the change in 3D-QCA DS%. Results Of 300 enrolled patients, 265 had serial follow-up, of which 193 underwent serial QFR/3D-QCA analysis in 282 non-IRA. Baseline mean QFR was 0.96[IQR 0.91-0.98] and mean DS% 36.96±7.88% in the alirocumab group vs. 0.96[IQR 0.91-0.99] (p=0.593) and 36.63±8.46% (p=0.742) in the placebo group. At 1-year, QFR increased in 50/94 (53.2%) patients with alirocumab vs. 40/99 (40.4%) with placebo (Δ12.8%; OR=1.7, 95%CI 0.9-3.0; p=0.076). When excluding non-IRA with QFR >0.95, QFR increased in 37/57 (64.9%) patients with alirocumab vs. 22/50 (44.0%) with placebo (Δ20.9%; OR=2.4, 95%CI 1.1-5.2; p=0.031). DS% decreased by -1.03±7.28% with alirocumab and increased by +1.70±8.27% with placebo (Δ-2.54%, 95%CI -4.51 to -0.57; p=0.012). Conclusions Treatment of AMI patients with alirocumab vs. placebo for 1 year resulted in a significant regression in angiographic DS%. While no overall improvement of coronary hemodynamics was observed with alirocumab as compared to placebo, potential benefits were found in alirocumab treated patients with baseline QFR ≤0.95.Figure 1.Flowchart and primary endpointFigure 2.Secondary endpoint