Left Atrial Volumetric and Functional Remodeling Post-Pulmonary Vein Isolation: Insights from Cardiac Magnetic Resonance Imaging

To assess left atrial (LA) volumetric and functional remodeling parameters using cardiac magnetic resonance (CMR) imaging early and late after pulmonary vein isolation (PVI) in atrial fibrillation (AF) patients. This study involved 61 AF patients undergoing radiofrequency (RF) PVI. CMR scans were performed pre-PVI, within 72hours and 3 months post-PVI. LA volumes and strain were assessed using two- and four-chamber cine images. Early AF recurrence was monitored during 3 months follow-up.LAVImin significantly increased early post-PVI (22.5±8.7mL/m² to 25.8±9.9mL/m²,p<0.01). At 3 months, both LAVImin and LAVImax significantly reduced compared to early post-PVI (25.4±8.87mL/m2 to 19.4±7.7mL/m2,p<0.001;48.2±12.7mL/m2 to 38.7±10.6mL/m2,p<0.001, respectively), as well as compared to baseline (22.5±8.7mL/m2 to 20.1±8.5mL/m2,p=0.04;45.6±11.8mL/m2 to 39.3±11.2mL/m2,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 3 months, 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%), LA volume reduction and partial functional recovery was not observed during 3 months post-PVI. LA volumes significantly reduced 3 months post-PVI. While LA function initially declined, it showed partial recovery at 3 months. 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.