Longitudinal Left Atrial Remodeling With Pharmacological Rhythm Versus Rate Control in Paroxysmal and Persistent Atrial Fibrillation

Purpose Evidence regarding left atrial (LA) remodeling with pharmacological rhythm control remains limited, particularly in patients with atrial fibrillation (AF) outside heart‐failure‐specific populations. Methods This single‐center retrospective cohort included 156 adults with paroxysmal or persistent AF receiving mutually exclusive pharmacological rate‐control ( n = 92) or rhythm‐control ( n = 64) therapy who underwent two transthoracic echocardiograms. LA remodeling was assessed using serial echocardiography, and clinical outcomes were evaluated after the second examination. Results Among 74 patients with paired left atrial volume index (LAVI) measurements, LAVI increased from 39.9 to 50.3 mL/m 2 with rate control ( p < 0.001) but remained unchanged with rhythm control (44.9 to 43.4 mL/m 2 ; p = 0.465). After adjustment for baseline LAVI and clinical covariates, rhythm control was associated with a 9.38 mL/m 2 lower follow‐up LAVI (95% CI, ‐15.53 to ‐3.24; p = 0.003). The association with lower follow‐up LAVI was also observed among patients without heart failure and remained similar in sensitivity analyses. During post‐landmark follow‐up, rhythm control was associated with a lower hazard of all‐cause mortality or stroke hospitalization (adjusted HR, 0.46; 95% CI, 0.24–0.88; p = 0.019). Conclusion Pharmacological rhythm control was associated with more favorable longitudinal LA remodeling than rate control, including among patients without heart failure, and was also associated with a lower hazard of subsequent all‐cause mortality or stroke hospitalization.