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.