Remnant cholesterol and residual cardiovascular risk in diabetic patients undergoing coronary revascularization: insights from a nationwide ohort

Background Remnant cholesterol (remnant-C) is an emerging contributor to residual cardiovascular risk, particularly in patients with diabetes mellitus (DM). Purpose To evaluate the prognostic impact of remnant-C levels in diabetic patients who underwent percutaneous coronary intervention (PCI) or coronary artery bypass graft (CABG). Methods We identified 15,824 patients with coronary artery disease and DM among 525,646 individuals who underwent PCI or CABG between 2011 and 2020 based on the National Health Insurance Service (NHIS) database. Remnant-C was calculated as total cholesterol minus low-density lipoprotein cholesterol and high-density lipoprotein cholesterol. The primary endpoint was major adverse cardiovascular and cerebrovascular events (MACCE), defined as cardiovascular death, myocardial infarction, repeat revascularization, or non-fatal stroke. Results Patients were stratified into tertiles according to remnant-C levels: T1 (<18.5 mg/dL; n=5,014), T2 (18.5–28.5 mg/dL; n=5,515), and T3 (≥28.5 mg/dL; n=5,295). After adjustment for demographic factors, comorbidities, and lipid-lowering therapies, the risk of MACCE increased stepwise across tertiles compared with T1:T2 (hazard ratio [HR] 1.12; 95% confidence interval [CI] 1.04–1.12; p=0.001), and T3 (HR 1.19; 95% CI 1.12–1.23; p<0.001). The cubic spline curve demonstrated a linear correlation between remnant-C levels and MACCE incidence. Conclusions Elevated remnant-C levels were independently associated with adverse cardiovascular outcomes in diabetic patients undergoing coronary revascularization, supporting remnant -C as a potential therapeutic target in this high-risk population.