Should we consider low LDL-cholesterol a marker of in-hospital bleeding in patients with acute coronary syndrome undergoing percutaneous coronary intervention?

Aims Emerging evidence has linked cholesterol metabolism with platelet responsiveness. We sought to examine the dose-response relationship between low-density lipoprotein cholesterol (LDL-C) and major in-hospital bleeds in acute coronary syndrome (ACS) patientsMethods and results Among 42 378 ACS patients treated with percutaneous coronary intervention (PCI) enrolled in 240 hospitals in the Improving Care for Cardiovascular Disease in China-ACS project from 2014 to 2019, a total of 615 major bleeds, 218 ischaemic events, and 337 deaths were recorded. After controlling for baseline variables, a non-linear relationship was observed for major bleeds, with the higher risk at lower LDL-C levels. No dose-response relationship was identified for ischaemic events and mortality. A threshold value of LDL-C <70 mg/dL was associated with an increased risk for major bleeds (adjusted odds ratio: 1.49; 95% confidence interval: 1.21-1.84) in multivariable-adjusted logistic regression models and in propensity score-matched cohorts. The results were consistent in multiple sensitivity analyses. Among ticagrelor-treated patients, the LDL-C threshold for increased bleeding risk was observed at <88 mg/dL, whereas for clopidogrel-treated patients, the threshold was <54 mg/dL. Across a full spectrum of LDL-C levels, the treatment effect size associated with ticagrelor vs. clopidogrel on major bleeds favoured clopidogrel at lower LDL-C levels, but no difference at higher LDL-C levelsConclusions In a nationwide ACS registry, a non-linear association was identified between LDL-C levels and major in-hospital bleeds following PCI, with the higher risk at lower levels. As the potential for confounding may exist, further studies are warranted.