Triglyceride-to-HDL Cholesterol Ratio Is Associated with Ischemic Stroke Risk in Patients—With Paroxysmal Atrial Fibrillation

<b>Background:</b> Ischemic stroke remains the most feared complication of atrial fibrillation (AF), and thromboembolic risk is commonly estimated using clinical scores that may not fully capture the cardiometabolic dimension of cerebrovascular vulnerability. The aim of this research was to assess whether additional parameters can be used, to predict ischemic stroke risk in patients with AF, in order to explore whether TG/HDL-C may complement conventional clinical risk scores for ischemic stroke risk stratification in PAF, and to better characterize a metabolically high-risk phenotype beyond the recommendations provided by the CHA₂DS₂-VA score, which is useful but still far from perfect in predicting AF-associated ischemic stroke risk. <b>Methods:</b> In this retrospective, single-center observational study, we evaluated whether the triglyceride-to-high-density lipoprotein cholesterol ratio (TG/HDLc), a simple surrogate of atherogenic dyslipidemia and insulin resistance, is associated with ischemic stroke risk in patients with paroxysmal atrial fibrillation (PAF). We screened 1111 consecutive AF admissions between 1 January 2015 and 31 December 2016 and, from these 1111 AF cases, we extracted only the patients with PAF for analysis. Patients were stratified based on TG/HDLc values into two groups, Group 1 (TG/HDLc > 2.5; n = 155) and Group 2 (TG/HDLc < 2.5; n = 194). Statistical analysis was performed with MedCalc v23.4.0 using Chi-square and unpaired/Welch's t-tests as appropriate, Pearson correlations, Kaplan-Meier analysis with log-rank testing, Cox regression for first ischemic stroke, and multivariable logistic regression to identify independent correlates of TG/HDLc > 2.5. <b>Results:</b> Patients with TG/HDLc > 2.5 had a significantly higher prevalence of ischemic stroke after AF onset compared with those with TG/HDLc < 2.5 (37.4% vs. 21.1%, <i>p</i> = 0.0008), despite similar CHA₂DS₂-VA and HAS-BLED scores, and also exhibited a higher burden of cerebrovascular and neurodegenerative findings, including cortical atrophy and cerebral lacunarism. Ischemic stroke-free survival curves diverged significantly over time (log-rank <i>p</i> = 0.0186), and an elevated TG/HDLc ratio was associated with a 68% higher hazard of first ischemic stroke (HR 1.68; 95% CI 1.09-2.60). In multivariable analysis, type 2 diabetes mellitus (OR 4.53), hyperuricemia (OR 3.83), dyslipidemia (OR 1.94), stroke (OR 1.77), and cortical atrophy (OR 4.48) were independently associated with TG/HDLc > 2.5. <b>Conclusions:</b> These findings suggest that TG/HDLc identifies a metabolically high-risk PAF phenotype associated with greater cerebrovascular burden and reduced ischemic stroke-free survival, providing an inexpensive and broadly available marker that may complement conventional clinical risk scores.