Impact of lesion sets on mid-term results of surgical ablation procedure for atrial fibrillation

Objectives: The objective of this study was to evaluate the effects of different lesion sets of ablation in patients undergoing mitral surgery plus maze. Background: The role of lesion sets on outcome after maze is poorly defined. Methods: A total of 141 patients were prospectively followed up. Two different lesion sets were prepared: 32 patients underwent a radiofrequency left atrial lesion set of maze ("limited"), and 109 had combined left and right atrial lesion sets of maze ± ganglionic plexi isolation ("extensive"). A longitudinal observational study assessed the role of "extensive" versus "limited" ablation on atrial fibrillation (AF), New York Heart Association (NYHA) functional class II/III, treatment with antiarrhythmic drugs, follow-up recovery of the ratio of E- to A-wave (E/A), and survival and time to hospitalization (overall and for heart failure). Results: The prevalence of AF over time was lower in the "extensive" arm (adjusted relative risk [RR]: 0.10; 95% confidence interval [CI]: 0.03 to 0.31; p <0.001), with significantly lower prevalence at discharge, 3 months, and 18 months. The prevalence of patients in NYHA functional class II/III over time was lower in the "extensive" arm (adjusted RR: 0.11; 95% CI: 0.03 to 0.34; p <0.001), with significant differences at any assessment (except the third month). The differences in E/A recovery and use of antiarrhythmic drugs were less marked, with an RR of 1.55 (95% CI: 0.99 to 2.42; p = 0.05) and RR of 0.76 (95% CI: 0.54 to 1.06; p = 0.11), respectively, with a significantly lower prevalence of antiarrhythmic drugs in the "extensive" ablation arm at 12, 18, and 24 months. Rates of hospitalization for heart failure, overall hospitalization, and the combined event death/hospitalization were lower in the "extensive" arm (p = 0.11, p = 0.003, and p = 0.002, respectively). Conclusions: The addition of right-sided ablation improves clinical and electrophysiologic results after maze procedure.