Left ventricular wall thickness and functional recovery after atrial fibrillation ablation in patients with systolic dysfunction.

BACKGROUND: Left ventricular functional recovery after atrial fibrillation (AF) ablation varies widely in patients with systolic dysfunction. OBJECTIVE: This study aimed to evaluate whether baseline left ventricular wall thickness (LVWT) and its regional heterogeneity predict recovery of left ventricular ejection fraction (LVEF) after AF ablation. METHODS: Of 5535 consecutive patients undergoing first-time AF ablation (2012-2024), 342 with a baseline LVEF of <50% (median age 64 years; 86% male; 19% with previous myocardial infarction) were retrospectively analyzed. Multidetector computed tomography was performed before ablation, and LVWT was quantified using a 16-segment model at end-diastole. Mean LVWT and its standard deviation (SD) across segments were calculated. The primary endpoint was the 6-month change in LVEF (ΔLVEF) on echocardiography. RESULTS: Median mean LVWT and SD of LVWT were 7.03 mm (6.19-8.00) and 1.20 mm (0.95-1.50), respectively. LVEF improved from 38.7% (32.0%-44.4%) to 56.0% (44.3%-62.0%) at 6 months (P < .001). In multivariable linear regression, higher mean LVWT was independently associated with greater ΔLVEF (1.72% per 1 mm; 95% confidence interval, 0.83-2.61; P < .001), whereas greater LVWT heterogeneity (SD) was associated with less ΔLVEF (-4.02% per 1 mm; 95% confidence interval, -6.64 to -1.40; P = .003). Patients with reduced thickness and high heterogeneity (mean LVWT <7.0 mm; SD of LVWT >1.2 mm) had the highest incidence of heart failure hospitalization or cardiovascular death. CONCLUSION: Baseline LVWT and its regional heterogeneity were independently associated with postablation functional recovery in patients with a baseline LVEF of <50%. Preprocedural LVWT assessment may help estimate myocardial reserve and expected functional recovery after AF ablation.