Primary results of the Spanish Cryoballoon Ablation Registry: acute and long-term outcomes of the RECABA study

Abstract

Cryoablation is safe and effective for the treatment of atrial fibrillation (AF) in controlled clinical trials, but contemporary real-world usage and outcomes are limited. The Report of the Spanish Cryoballoon Ablation Registry (RECABA) was designed to evaluate acute and 12-month outcomes of cryoballoon ablation for the treatment of AF in Spain. Patients from 27 Spanish centers were prospectively enrolled. Patients were treated with cryoballoon ablation and managed according to standard of care protocols at each center. The primary endpoint was ≥ 30 s freedom from AF at 12-month after a 3-month blanking period. Secondary endpoints included a description of patient characteristics, cryoablation procedural strategy and safety, and predictors of efficacy. In total, 1742 patients (71.4% PAF, 68.8% male, mean age 58.02 ± 10.40 years, 76.1% overweight or obese, CHA₂DS₂-VASc index 1.40 ± 1.28) were enrolled. Patients received 7.2 ± 2.67 cryo-applications. PV potentials could be detected in 61% of the PVs during ablation, with a mean time to block of 52.9 ± 37.02 s. Acute PVI was observed in 97% of PVs with 75.8% isolated with the first cryo-application. Mean procedural time was 113 ± 41 min. Acute complications occurred in 4.4% of the cases. With follow-up in 1628 patients, AF-free survival was 78.5% (PAF: 80.6% vs PersAF 73.3%; p < 0.001). Left atrium enlargement, female sex, non-PAF, and early recurrence were independent predictors of AF recurrence (p < 0.05). RECABA provides detailed insight into current dosing practices and demonstrates cryoablation is safe and effective in real-world use.ClinicalTrials.gov number: NCT02785991.

Figure 1

Visual representation of RECABA protocol.

Figure 2

Histograms of the distribution of frequencies: total cryotherapy time (A), total procedural time (B), time-to-effect (C), temperature at PVI (D), minimal temperature during application (E), time per-application (F). SD standard deviation.

Figure 3

Kaplan–Meier survival curves for AF recurrence at 12-months for all patients (A). Comparison between PAF versus perAF (B).

Figure 4

Kaplan–Meier survival curves for AF recurrence at 12-months. Analysis of different predictive factors for AF recurrence.

Figure 5

AF recurrence and no-recurrence at 12-months of follow-up (absolute number of patients) by center experience. Centers were divided into four quartiles of expertise with a fixed range of 55 patients in each quartile, increasing in the level of experience. There was not statistical difference regarding either overall recurrence at 12-month follow-up or the rate of adverse events. Procedure characteristics were different between quartiles (Table S2).

Figure 6

Flow-chart showing AF recurrence data according to type of AF, AAD at discharge and AAD usage at the final follow-up for the entire population. (see text for details).