Catheter ablation in the role of rescuer in treatment of recurrent atrial fibrillation following surgical ablation

摘要

Atrial fibrillation (AF) is the most common cardiac arrhythmia in clinical practice, which can induce cardiac dysfunction and strokes, causing a substantial socioeconomic burden.1, 2 Patients with AF undergoing cardiac surgery have an increased risk of ventricular dysfunction, comorbidities, and mortality.3 Eradicating AF during cardiac surgery could decrease the number of adverse cardiovascular events and improve clinical outcome. Although the Cox-Maze procedure is highly successful in maintaining sinus rhythm,4 its difficulty and complexity reduces the procedure’s utilization by cardiac surgeons in cardiovascular surgery.5 Surgical ablation using a variety of energy sources such as radiofrequency (RF) energy, microwave, cryoablation, laser, and high-intensity ultrasound, has been widely utilized to create the linear lines which simplify the procedure, and thus is typically more feasible than the Cox-Maze procedure for most surgeons.5 Bipolar RF delivers energy between two closely approximated electrodes embedded in the jaw of a clamp device, creating discrete linear lesions and is commonly applied in surgical ablation of AF. However, the limitation of bipolar RF ablation is that it can only clamp the tissue within the jaws of the device, and an incomplete block might occur in some linear lesions. The success rates in treatment of AF using bipolar ablation with concomitant cardiac surgery varied from 65% to 95% following a 6-month follow-up.6 Surgical experience, differing ablation technologies, and inconsistent definitions of procedural success and follow-up could cause the discordant results. Pulmonary vein (PV) isolation with more extensive lesion sets including mitral isthmus line and biatrial lines, has been reported to provide a better long-term outcome than PV isolation only.7 A recent meta-analysis study showed that surgical ablation had a lesser incidence of recurrent AF compared to catheter ablation at 6 months [73% vs. 61%; Odds Ratio (OR), 2.19; 95% confidence interval (CI) 1.21–3.96; p = 0.01] and 12 months (74% vs. 43%; OR, 3.91; 95% CI, 2.38–6.42; p < 0.00001).8 The incidence of pacemaker implantation was higher in surgical ablation versus catheter ablation, but no difference in the frequency of stroke or cardiac tamponade was noted. A blinded, large, multicenter, randomized, control trial is needed to compare the efficacy of surgical and catheter ablation in the treatment of AF.