Remnant cholesterol and cardiovascular risk in maintenance haemodialysis

BACKGROUND: Remnant cholesterol (remnant-C) has emerged as a marker of residual cardiovascular risk beyond low-density lipoprotein cholesterol (LDL-C) but data in haemodialysis populations remain limited. We investigated the association of remnant-C with cardiovascular and mortality outcomes in maintenance haemodialysis patients. METHODS: This post-hoc analysis included 624 patients from the prospective RISCAVID cohort. Remnant-C was calculated as total cholesterol minus high-density lipoprotein cholesterol minus directly measured LDL-C. The primary endpoint was 3-point major adverse cardiovascular events (MACE), defined as cardiovascular death, nonfatal myocardial infarction, or nonfatal ischaemic stroke. All-cause mortality was analysed as a secondary endpoint. Associations were assessed using multivariable Cox regression models. RESULTS: During a median follow-up of 31 months, 328 patients experienced a 3-point MACE and 375 died. Remnant-C was independently associated with 3-point MACE after adjustment for age, sex, traditional cardiovascular risk factors, LDL-C, and statin therapy (HR 1.06 per 10 mg/dl increase, 95% CI 1.01-1.11). The association remained significant after additional adjustment for the Geriatric Nutritional Risk Index (GNRI) and normalized protein catabolic rate. Restricted cubic spline analysis showed a progressive increase in cardiovascular risk across increasing remnant-C concentrations without evidence of a nonlinear threshold effect. For all-cause mortality, neither remnant-C nor LDL-C retained prognostic significance after multivariable adjustment. Conversely, GNRI was independently associated with mortality risk, whereas it was not associated with cardiovascular events. CONCLUSION: In maintenance haemodialysis patients, remnant-C was independently associated with major cardiovascular events but not with all-cause mortality, whereas the GNRI was associated with mortality but not cardiovascular outcomes. These findings suggest distinct contributions of residual atherogenic risk and nutritional status to cardiovascular and survival outcomes in end-stage kidney disease.