Reply to Tannous et al.

Abstract

We thank Tannous et al. [1] for their valuable comments on our review [2]. We agree that pacemaker implantation is an important complication of surgical ablation of atrial fibrillation (AF). As we cited, a recent systematic review on minimally invasive radiofrequency ablation of AF found a rate of pacemaker implantation of 1.4%, which was considerably lower than the 6.9% presented by Tannous et al. and other authors [3]. This difference is likely related to the setting of AF ablation (lone intervention versus concomitant surgery, respectively). Indeed, a recent retrospective analysis of the predictors and risk of pacemaker implantation after the Cox-Maze procedure found concomitant procedures to be associated with a non-significantly higher risk than lone interventions (15 vs 6%, P = 0.060, at 1 year). Age was the single independent predictor of pacemaker implantation [4]. In concomitant AF ablation, associated cardiac diseases and procedures might influence the pacemaker implantation rate by inducing conduction or sinus-node disturbances. In our experience of concomitant AF ablation, pacemaker implantation was the most common complication. Nearly 15% of the patients (n = 170) required definitive pacemaker implantation following radiofrequency ablation (unpublished data). Patients undergoing bi-atrial ablation procedures had a significantly higher risk of postoperative pacemaker implantation (P < 0.001), which was in line with prior reports [3, 5]. Worku et al. compared several energy modalities and lesion sets, and suggested that microwave energy and right atrial ablation lines increased risk of postprocedural pacemaker implantation. Their findings were recently corroborated by Pecha et al., who identified bi-atrial ablation as the single independent predictor of pacemaker implantation. This is though not consensual as Kim et al. [6] suggested that bi-atrial cryoablation reduced AF recurrence without increasing postoperative complications, namely pacemaker implantation, when compared with procedures restricted to the left atrium. Pacemaker implantation was required only for a minor fraction of patients undergoing bi-atrial procedures (1.8%). Of note, Pecha et al. [3] found cryoablation to be associated with a marginally lower rate of pacemaker implantation in comparison with radiofrequency energy. In conclusion, pacemaker implantation is recognized as one of the main complications of AF ablation. Concomitant procedures and bi-atrial lesion sets seem to increase this risk, but further evidence on the independent predictors is eagerly warranted.