COMPARATIVE EFFECTIVENESS OF RADIOFREQUENCY PULMONARY VEIN ISOLATION PLUS AMIODARONE THERAPY IN PREVENTING POST-CORONARY ARTERY BYPASS GRAFTING ATRIAL FIBRILLATION
Objective. To evaluate the effectiveness of epicardial bipolar radiofrequency ablation (RFA) of pulmonary vein ostia (PV) in comparison with its being combined with amiodarone administration for post-CABG atrial fibrillation (AF) prevention. Methods. A single-centre, prospective randomized study (PULVAB), including 96 CAD patients with no history of AF, was conducted between January 2015 and December 2018. Group 1 (control; n=34) had standard CABG alone. Group 2 (n=29) received RFA of PV as an adjunct to CABG for prevention of postoperative AF (POAF). Group 3 patients (n=33) had RFA at the time of CABG and were given amiodarone. Allocation was concealed using sequentially-numbered opaque envelopes. The efficacy and safety of RFA concomitant with CABG were assessed, as both performed independently and combined with amiodarone administration, as well as intra-and postoperative course. Results. No differences were seen in operation length (p=0.937), cardiopulmonary bypass (CPB) or the aorta clamping times (р=0.377 and p=0.072, respectively). The study groups (CABG, CABG-RFA, CABG-RFA-amiodarone) did not differ statistically in the number of shunts placed - 3.17±0.61, 3.10±0.51 and 2.94±0,6 (p=0,121). No significant difference was noted in RFA duration between Groups 2 and 3 - 11.7±3.7 and 11.4±6.3 min, respectively (p=0,834). AF was found to occur most commonly at postoperative days two or four. The isolated CABG surgery group patients developed POAF most often of all (32,4%). The incidence of POAF was lower after RFA concomitant to CABG - 20.7% (р=0,29). A significant difference was identified in POAF incidence between Groups 1 and 3- 32.4% and 6.1%, respectively (p = 0.0065). Differences between Groups 2 and 3 proved not to be statistically significant (р= 0,086). Sinus rhythm in most of those who had developed arrhythmias was restored by pharmacological cardioversion except for three patients (one in each group). At discharge, 97.1% , 96.7% and 97% of the subjects in Groups 1, 2 and 3, respectively, exhibited sinus rhythm (p>0,05).There was no in-hospital mortality in any of the groups. Neither were there any wound complications, reoperations, perioperative myocardial infarction or cerebral circulatory disorders observed. No difference was revealed in the severity and frequency of renal or respiratory failure. The mechanical lung ventilation time and duration of stay in the ICU in the isolated CABG group were shown to be increased as compared with the CABG-RFA and CABG-RFA-amiodarone groups (p<0.05). Conclusion. The evidence from the pilot study (PULVAB) suggests that bipolar ablation of PV does not significantly complicate CABG, while being combined with amiodarone administration for prevention of rhythm disorders it significantly reduces the incidence of POAF. The in-hospital incidence of POAF tended to decrease, which was not statistically significant, though. Evaluating the efficacy of RFA concomitant with CABG, as performed independently, invites further investigation with more data analysis.