Effects of remnant cholesterol on the efficacy of genotype-guided dual antiplatelet in CYP2C19 loss-of -function carriers with minor stroke or transient ischaemic attack: a post-hoc analysis of the CHANCE-2 trial

Background The atherogenicity of remnant cholesterol (RC), a contributor to residual risk of cardiovascular events, has been underlined by recent guidelines. We aimed to evaluate the relationship between RC levels and the efficacy and safety of genotype-guided dual antiplatelet therapy in the CHANCE-2 trial. Methods This post-hoc study used data from the CHANCE-2 trial, which was a randomised, double-blind, placebo-controlled trial of 6412 patients (aged >40 years) enrolled from 202 hospitals in China, between Sept 23, 2019, and March 22, 2021, who carried CYP2C19 loss-of-function alleles and had either an acute minor stroke or high-risk transient ischaemic attack (TIA), and could start treatment within 24 h of symptom onset. Participants received either (1:1) ticagrelor plus aspirin (control) or clopidogrel plus aspirin (intervention) and the effect of reducing the 3-month risk of any new stroke was assessed (ischemic or haemorrhagic, primary outcome). From the CHANCE-2 study population, we enrolled 5890 patients with complete data on RC. The cutoff point of RC for distinguishing patients with greater benefit from ticagrelor-aspirin versus clopidogrel-aspirin was determined with subpopulation treatment effect pattern plot. The primary efficacy and safety outcome was recurrent stroke and severe or moderate bleeding within 90 days, respectively. CHANCE-2 is registered with ClinicalTrials.gov, NCT04078737. Findings The cutoff to define elevated RC was 0.91 mmol/L. Ticagrelor-aspirin versus clopidogrel-aspirin was associated with a reduced risk of recurrent stroke in patients with non-elevated RC levels (122 [5.3%] versus 179 [7.8%]; hazard ratio [HR], 0.68; 95% confidence interval [CI], 0.54–0.85), but this benefit was absent in those with elevated RC levels (58 [8.4%] versus 48 [7.3%]; HR, 1.10; 95% CI, 0.73–1.65; P -interaction = 0.03). When analyzed as a continuous variable, the benefit of ticagrelor-aspirin on recurrent stroke decreased as RC levels increased. The rates of severe or moderate bleeding between treatment groups were similar across RC categories (0.3% versus 0.3%, P -interaction = 0.95). Interpretation Our post-hoc findings suggest that RC could be a potential biomarker to discriminate patients who received more benefits from ticagrelor-aspirin versus clopidogrel-aspirin therapy in CYP2C19 loss-of-function carriers with minor stroke or TIA. These findings need to be validated in an independent study. Funding The National Key Research and Development Program of China, Beijing Natural Science Foundation Haidian original innovation joint fund, Fund for Young Talents of Beijing Medical Management Center, the high-level public health talents, Training Fund for Open Projects at Clinical Institutes and Departments of Capital Medical University; and Salubris.