Association between remnant cholesterol and stroke among patients with atrial fibrillation: a population-based cohort study

BACKGROUND Remnant cholesterol (RC) is a modifiable risk factor for stroke in the general population; however, its role in stroke risk among patients with atrial fibrillation (AF) remains unclear. OBJECTIVE This study aimed to examine the associations between key RC metrics, including baseline levels, cumulative measures, average real variability (ARV), and RC/low-density lipoprotein cholesterol (LDL-C) discordance, and stroke risk in patients with AF. METHODS A total of 2154 patients with AF from the Atherosclerosis Risk in Communities database were analyzed. RC was calculated as total cholesterol minus LDL-C and high-density lipoprotein cholesterol. Cox proportional hazards models were used to assess the associations of 4 key RC metrics with stroke risk, adjusting for potential confounders. RESULTS Higher baseline RC levels were significantly associated with an increased risk of stroke, with an adjusted hazard ratio (HR) of 1.41 (95% CI: 1.02-1.94, P = .039). This association was linear (P overall = .008). Each 1-SD increase in RC corresponded to a 11% higher stroke risk (HR = 1.11, P = .039). Similar associations were observed for ARV (HR = 2.06, P = .041) and cumulative RC levels (HR = 1.11, P = .002). Additionally, the concordant high RC/LDL-C group was linked to a higher stroke risk (HR = 1.93, P = .01). CONCLUSION Elevated RC baseline levels, variability, and cumulative exposure are independently associated with an increased risk of stroke in patients with AF, highlighting the need for lipid-lowering interventions targeting RC levels to mitigate stroke risk in this high-risk population.