Abstract 15729: Effect of Metformin on Outcomes of Catheter Ablation for Atrial Fibrillation

Abstract

Background: Diabetes mellitus (DM) and glycemic control are risk factors for atrial fibrillation (AF). Metformin may have antifibrillatory properties by altering atrial metabolism. It is unknown whether metformin has favorable effects on the outcomes of catheter ablation (CA) for AF. Objective: To determine whether metformin use is associated with maintenance of sinus rhythm after CA for AF. Methods and Results: A 1 st CA was performed in 271 consecutive patients with DM and AF (age: 65±9 years, women: 34 %; and paroxysmal AF: 50%). A total of 182 (67%) patients were treated with metformin and 79/182 were also receiving other antidiabetics or insulin. HbA1c and preprocedural fasting blood glucose were similar among the patients treated with and without metformin (7.2±1.4% vs. 7.2±1.3%, P=0.95 and 162± 61 vs. 159±66 mg/dL, P=0.72). At a median of 10 months (IQR: 5-23, mean 15±13 months) after CA, 100/182 patients (55%) on metformin remained in sinus rhythm without concomitant antiarrhythmic drugs (AAD) compared to 36/89 patients (40%) not receiving metformin (P=0.03). On K-M analysis, patients on metformin were more likely to stay in sinus rhythm after CA, with or without AADs (P<0.001, log-rank, Figure). On Cox proportional hazards analysis, adjusted for age, gender, BMI, type of AF(paroxysmal vs. non-paroxysmal), fasting blood glucose, AAD use, obstructive sleep apnea, chronic kidney disease, and left atrial diameter, metformin use was associated with a ~35% lower probability of recurrent atrial arrhythmia(HR: 0.65, ±95% CI: 0.44-0.97, P=0.04). Increase in left atrial diameter (per mm, HR: 1.05, ±95% CI:1.01-1.08, P=0.001) and non-paroxysmal AF (HR: 1.9, ±95% CI: 1.3-2.9, P=0.001) were associated with a higher risk of recurrence after CA of AF. Conclusion: In patients with DM, the use of metformin was associated with a significant reduction in recurrent atrial arrhythmias after CA for AF independent of the other risk factors, including preprocedural glycemic control.