CTI ablation using CMAC achieved 97% block success without touch-up, with transient AV block in 57% fully resolving, and low coronary artery spasm incidence.
Does pulsed field ablation using an over-the-wire circular multielectrode array catheter effectively and safely achieve cavotricuspid isthmus block in patients undergoing atrial fibrillation ablation?
Pulsed field ablation for the cavotricuspid isthmus using a circular multielectrode array catheter is highly effective and safe, achieving a 97% block rate without the need for touch-up ablation.
Absolute Event Rate: 0% vs 0%
Abstract Background Pulsed field ablation (PFA) is an ablation technique with minimal impact on non-cardiac tissues, and various types of PFA catheters are available for atrial fibrillation (AF) ablation. The efficacy of the over-the-wire circular multielectrode array catheter (CMAC) for AF has been reported (1); however, no studies have been published on its use for cavo-tricuspid isthmus (CTI) ablation. Purpose The purpose of this study is to evaluate the efficacy and safety of CTI ablation using CMAC. Methods A total of 110 consecutive patients (69 ± 11 years old, 75 males, 30 paroxysmal AF) who underwent prevention of atrial flutter recurrence or empirical CTI ablation using CMAC during AF ablation at our institution were included. In all cases, after pulmonary veins isolation, a guidewire was placed in the right ventricular apex, and ablation was performed using up to the fourth electrode of the CMAC, ensuring that all electrodes were in contact with the CTI under atrial pacing from proximal coronary sinus. All applications using the CMAC were delivered synchronized to the R wave. In all cases, differential pacing and activation mapping were performed using an additional 10-pole electrode catheter to confirm bidirectional block of CTI. The study evaluated the CTI block achievement rate, the number of applications required to achieve the block, the incidence and predictors of conduction gaps, and complications particularly coronary artery spasm and the impact on atrioventricular conduction during ablation retrospectively. Results All patients underwent ablation with the adjunctive use of the Ensite system. Ultimately, CTI block was achieved without the need for touch-up ablation in 107 patients (97%), with a median of 5 applications (interquartile range: 4–8). Among them, 70 patients (64%) achieved block within two applications. In 29 cases, conduction gaps remained after four applications or block initially achieved recurred. Patients who achieved CTI block within four applications had significantly higher minimum and mean peak frequency values (PF) measured by CMAC in the 10 beats preceding successful ablation compared to those who did not (Minimum PF: 164 ± 49 vs. 138 ± 49, p=0.021; Mean PF: 224 ± 52 vs. 199 ± 50, p=0.033). During CTI ablation using CMAC, transient 1- or 2-degree atrioventricular block occurred in 59 patients (57%), but all cases recovered. In one case, ST-segment elevation was observed in the inferior leads 7 minutes after ablation, and coronary angiography revealed right coronary artery spasm, which resolved with isosorbide administration. No other complications were observed. Conclusions CTI ablation using the CMAC demonstrated a high success rate without touch – up ablation, with no adverse effects on atrioventricular conduction and a low incidence of coronary artery spasm. PF measured by CMAC were suggested as potential predictors of successful CTI block.
Inaba et al. (Sat,) reported a other. CTI ablation using CMAC achieved 97% block success without touch-up, with transient AV block in 57% fully resolving, and low coronary artery spasm incidence.