Early Pulmonary Vein Conduction Recovery after Catheter Ablation of Atrial Fibrillation

Acute and long-term outcomes of pulmonary vein isolation and left atrial substrate modification for non-paroxysmal atrial fibrillation: a non-randomized trial

Background

The long-term success rate of nonparoxysmal atrial fibrillation (AF) treated with pulmonary vein isolation (PVI) alone is not ideal. This may indicate atrial fibrosis as a major cause of recurrence. Therefore, the aim of this study is to investigate the efficacy of left atrial substrate modification (LASM) by targeting low-voltage area.

Methods

A total of 157 consecutive patients with drug-refractory nonparoxysmal AF who underwent radiofrequency ablation during hospitalization in the Third People's Hospital of Chengdu from April 2017 to August 2021 were prospectively included. Stepwise ablation was performed in two different orders: LASM first (n=53) and PVI first (n=104) group. All patients underwent ablation during AF, and the procedural endpoint was AF termination during ablation. In the LASM first group, LASM was performed first and if AF was terminated, PVI was not performed. Similarly, in the PVI first groups, LASM was performed if AF was not terminated. The primary outcome were AF termination and freedom from AF. The secondary outcome was adverse events. Cox regression analysis was used to define predictors of AF termination, and Kaplan-Meier analysis was used to assess differences between groups in AF freedom.

Results

The baseline characteristics of the two groups were similar. At a median follow-up of 16 months, the 112 patients (39 in LASM first group and 73 in PVI first group) with AF termination had a higher success rate than the 45 patients who had no AF termination (78.6% vs. 57.8%; P<0.01). The AF termination rate (24/53, 45.3% vs. 12/104, 11.5%; P<0.01) and AF freedom (20/24, 83.3% vs. 7/12, 58.3%; P=0.13) by LASM alone was higher than PVI alone. There were 3 cases of heart failure and 1 case of stroke (4/53) in the LASM first group, and 1 case of pericardial tamponade, 5 cases of heart failure and 1 case of stroke (7/104) in the LASM first group (7.5% vs. 6.7%; P>0.05).

Conclusions

LASM provides higher immediate success and a slightly better long-term success rate compared to PVI. Patients who terminated AF were more likely to have AF freedom than those who did not. AF termination during procedure may improve symptoms and reduce hospitalization.

Incidence of early pulmonary vein reconnections using different energy sources for pulmonary vein isolation: Multielectrode phased radiofrequency vs second-generation cryoballoon

OBJECTIVE

To determine and compare the incidence of early recurrence of conduction after pulmonary vein isolation (PVI) using two different ablation technologies: phased radiofrequency by a multipolar ablation catheter (PVAC) and cryo-ablation by a second-generation cryoballoon (CB).

METHODS AND RESULTS

Two hundred patients (pts) with atrial fibrillation underwent PVI with PVAC (Group 1) or CB (Group 2), with 100 pts in each group. The incidence of PV reconnection (PVR) for each vein was examined in both groups at least 30 minutes after successful PVI. There were no significant clinical differences between both groups. Total procedure-, fluoroscopy-, and left atrial (LA) dwell time were significantly shorter in Group 2 pts (P < .0001). Early PVR was recorded in 69/388 (18%) isolated PVs or left common trunks (CTs) in Group 1 compared with 25/386 (7%) in Group 2 (P < .0001). Forty-three pts in Group1 were found to have PVR compared with 22 pts in Group 2 (P = .0015). Group 1 pts with CTs showed significantly more PVR than pts of Group 2 (P = .047). In both groups, CTs and CT branches were found to reconnect significantly more frequent compared with all other veins.

CONCLUSION

Both PVAC and CB are effective to achieve PVI. Early PVR is observed with the significantly lower frequency with second-generation CB compared with PVAC, contributing to shorter procedure-, fluoroscopy, and LA dwell times. CTs and CT branches exhibit the highest incidence of PVR for both devices.

High-density mapping and ablation of concealed low-voltage activity within pulmonary vein antra results in improved freedom from atrial fibrillation compared to pulmonary vein isolation alone

BACKGROUND

Despite advancements, the goal of durable pulmonary vein isolation (PVI) in all patients undergoing ablation for atrial fibrillation (AF) remains elusive. New high-density mapping (HDM) allows detection of concealed low-voltage signals (CLVSs) that persist after PVI and may represent vulnerabilities in the lesion set.

OBJECTIVE

The purpose of this study was to determine the incidence of CLVSs after PVI and the effect of CLVS ablation on outcomes.

METHODS

We conducted a case control study comparing 150 patients undergoing HDM-guided PVI and subsequent CLVS mapping and ablation (39 redo, 111 de novo) against 452 historical controls undergoing traditional PVI alone. PVI was similarly performed and confirmed in both groups.

RESULTS

Baseline characteristics were similar, except left atrial size was larger in the HDM-guided group. Acute PVI was achieved in nearly all patients in both groups. In the HDM group, 31 of 150 patients exhibited CLVS after luminal PVI, and all were subsequently eliminated. During mean follow-up of 320 days, after controlling for baseline characteristics, the HDM-guided group exhibited a hazard ratio of 0.19 in freedom from AF (P <.001). De novo patients exhibited a hazard ratio of 0.44 relative to redo patients in the HDM-guided group. Both subgroups exhibited significantly lower event rates compared to controls in log-rank analysis (P <.001).

CONCLUSION

CLVSs are commonly identified with HDM after PVI, likely representing vulnerabilities in antral lesion sets. Ablation of these targets seems to significantly improve freedom from AF compared to PVI alone.