Abstract
Background
In a recent trial, cryoballoon (CB) ablation was non-inferior to radiofrequency ablation regarding effectiveness in atrial fibrillation (AF). Ablation index (AI) provides a more accurate estimation of ablation quality using three variables: power delivered with time, contact force and catheter stability. The additional benefit of AI-guided ablation versus CB ablation is unknown.
Objective
To compare AI-guided ablation and CB ablation for first pulmonary vein isolation (PVI) in patients with AF.
Methods
We assessed 141 patients (62±12 years old, 76 men and 126 paroxysmal AF) with drug refractory symptomatic AF submitted to AI-guided PVI or second-generation CB catheter. Endpoint was AF/AT/AFL recurrence after a 3-month blanking period with a minimum follow-up of 6 months. Cox regression was used to assess the relationship between type of ablation and AF recurrence.
Results
Fifty-seven patients underwent AI-guided PVI and 84 patients underwent CB ablation. The baseline characteristics are described in table 1. Procedure duration was significantly higher in AI group (150 vs 111 min, P<0.001) although requiring significant less fluoroscopy time (5 min vs 20 min; P<0.001). There was a transient phrenic nerve palsy in CB group and a cardiac tamponade in AI group. During a mean follow-up of 10±3 months there were 23 recurrences (27%) in CB group vs 7 recurrences (12%) in AI group (log rank 0.042) (Fig B). When adjusted for CHA2DS2-VASc score, left atrium diameter (mm) and type of AF (Cox regression), there was lower arrhythmia recurrence in AI group (HR 0.42; 95% CI 0.18–0.99; p=0.047).
Table 1. Baseline characteristics
Conclusion
In this analysis, AI-guided ablation was associated with lower arrhythmia recurrence when compared with CB ablation. This hypothesis should be further evaluated in a prospective randomized trial.
Incidence and characteristics of phrenic nerve palsy following pulmonary vein isolation with the second-generation as compared with the first-generation cryoballoon in 360 consecutive patients
