The Impact of Left Atrial Size on Long‐Term Outcome of Catheter Ablation of Chronic Atrial Fibrillation

Abstract

The left atrial (LA) size is an important predictor of atrial fibrillation (AF) procedural termination and the long-term outcome. We sought to evaluate the long-term outcome in regard to the LA size and procedural termination. Eighty-seven consecutive chronic AF patients (72 males, 53 +/- 10 years) underwent 3D mapping (NavX) and ablation. A stepwise approach including circumferential pulmonary vein (PV) isolation, linear ablation, and continuous complex-fractionated electrogram (CFE) ablation (targeting fractionation intervals of < 50 ms). Electrical cardioversion was applied to those without any procedural termination. The freedom from AF was defined as the maintenance of sinus rhythm without the use of any class I or III antiarrhythmic drugs after the blanking period. Among the 87 patients, all received a circumferential PV isolation, 93% a linear ablation, and 59% a continuous CFE ablation. Those with AF procedural termination (n = 30) had a better long-term outcome when compared with those without termination during a follow-up of 21 +/- 12 months. Moreover, a Kaplan-Meier analysis showed that in those with an LA diameter of less than 45 mm (n = 49), the freedom from AF rate was higher when procedural termination was achieved (P = 0.004). On the contrary, the outcome was comparable in those with an LA diameter of >or= 45 mm (n = 38), whether AF procedural termination occurred or not (P = 0.658). AF procedural termination was related to the long-term success during chronic AF ablation, especially in those with an LA diameter of less than 45 mm. The favorable effect of termination decreased when the LA diameter was >or= 45 mm.