Abstract
BACKGROUND: Atrial fibrillation (AF) ablation may induce reverse left atrial (LA) remodeling, yet few studies have prospectively evaluated its short- and long-term effects. This study assessed LA volumetric and functional remodeling using cardiovascular magnetic resonance (CMR) imaging early and late after pulmonary vein isolation (PVI) in AF patients. METHODS: This study involved 61 AF patients undergoing radiofrequency PVI. CMR scans were performed pre-PVI, within 72 h and 3months post-PVI. LA volumes and strain were assessed using two- and four-chamber cine images. Early AF recurrence was monitored during 3months follow-up. RESULTS: LAVImin significantly increased early post-PVI (22.5±8.7 mL/m² to 25.8±9.9 mL/m², p<0.01). At 3months, both LAVImin and LAVImax significantly reduced compared to early post-PVI (25.4±8.87 mL/m(2) to 19.4±7.7 mL/m(2), p<0.001; 48.2±12.7 mL/m(2) to 38.7±10.6 mL/m(2), p<0.001, respectively), as well as compared to baseline (22.5±8.7 mL/m(2) to 20.1±8.5 mL/m(2), p=0.04; 45.6±11.8 mL/m(2) to 39.3±11.2 mL/m(2), p<0.001, respectively). Early post-PVI, LA emptying fraction (LA EF), LA reservoir, and contractile strain significantly reduced compared to baseline (from 51.6±10.8% to 47.1±8.9%, p<0.01; 18.3±4.4% to 15.4±2.9%, p<0.001; 8.3±3.1% to 5.4±1.8%, p<0.001, respectively). At 3months, LA EF, LA reservoir, and contractile strain significantly increased as compared to early post-PVI (from 47.1±8.9% to 50.5±8.6%, p<0.01; 15.4±2.9% to 16.8±3.1%, p<0.01; 5.4±1.8% to 6.9±2.3%, p<0.001, respectively). However, LA reservoir and contractile strain remained significantly lower compared to baseline (18.3±4.4% to 16.8±3.1%, p=0.02; 8.3±3.1% to 6.9±2.3%, p<0.01, respectively). In patients with early AF recurrence 27.9% (17/61), LA volume reduction and partial functional recovery were not observed during 3months post-PVI. CONCLUSION: LA volumes significantly reduced 3months post-PVI. While LA function initially declined, it showed partial recovery at 3months. However, LA reservoir and contractile strain remained reduced compared to pre-PVI. LA reverse remodeling and partial LA functional recovery only occurred in patients without early AF recurrence.