Impact of Diagnosis-to-Ablation Time on AF Recurrence: Pronounced the First 3 Years, Irrelevant Thereafter

BACKGROUND

Diagnosis-to-ablation time (DAT) strongly predicts recurrence of atrial fibrillation (AF) after ablation. Whether this association holds with any lower and/or upper limits is unknown.

OBJECTIVES

The goal of this study was to assess the impact of DAT on AF recurrence in search of lower and upper DAT thresholds.

METHODS

A total of 2,000 patients with AF from 2 cohorts of 1,000 patients each (69% male; age 62 ± 10 years) undergoing pulmonary vein isolation (PVI) between 2005-2014 and 2017-2019 were followed up for 3 years.

RESULTS

Clinical success was achieved in 61.7% of patients. Median DAT decreased over time from 36 months (Q1-Q3: 12-72 months) in the first cohort to 12 months (Q1-Q3: 5-48 months) in the second cohort (P < 0.001). A multivariable Cox proportional hazards fitted model of AF recurrence rate in relation to DAT (range: 0-288 months) showed a steep rise in AF recurrence, from 27% to 40% in the first 36 months (d%/dt = 0.36), with a first inflection point at 36 months, and a less steep rise to 45% until 90 months (d%/dt = 0.09), with flattening beyond 90 months (d%/dt = 0.026). Rise in AF recurrence rate in the first 36 months was higher in patients with persistent AF (from 40% to 54%; d%/dt = 0.39) than in patients with paroxysmal AF (19% to 29%; d%/dt = 0.28).

CONCLUSIONS

The association between DAT and AF recurrence has no lower limit ("the shorter the better"), whereas little gain is to be expected beyond 36 months ("the longer the more irrelevant"). Our data advocate for performing PVI as early as possible, certainly within 3 years of AF diagnosis, and even more so in persistent AF.

Personalized assessment of the cumulative complication risk of the atrial fibrillation ablation track: The AF-TRACK calculator

Background

Atrial fibrillation (AF) ablation strategy is associated with a non-negligible risk of complications and often requires repeat procedures (AF ablation track), implying repetitive exposure to procedural risk.

Objective

The purpose of this study was to develop and validate a model to estimate individualized cumulative risk of complications in patients undergoing the AF ablation track (Atrial Fibrillation TRAck Complication risK [AF-TRACK] calculator).

Methods

The model was derived from a multicenter cohort including 3762 AF ablation procedures in 2943 patients. A first regression model was fitted to predict the propensity for repeat ablation. The AF-TRACK calculator computed the risk of AF ablation track complications, considering the propensity for repeat ablation. Internal (cross-validation) and external (independent cohort) validation were assessed for discrimination capacity (area under the curve [AUC]) and goodness of fit (Hosmer-Lemeshow [HL] test).

Results

Complications (N = 111) occurred in 3.7% of patients (2.9% of procedures). Predictors included female sex, heart failure, sleep apnea syndrome, and repeat procedures. The model showed fair discrimination capacity to predict complications (AUC 0.61 [0.55-0.67]) and likelihood of repeat procedure (AUC 0.62 [0.60-0.64]), with good calibration (HL χ² 12.5; P = .13). The model maintained adequate discrimination capacity (AUC 0.67 [0.57-0.77]) and calibration (HL χ² 5.6; P = .23) in the external validation cohort. The validated model was used to create the Web-based AF-TRACK calculator.

Conclusion

The proposed risk model provides individualized estimates of the cumulative risk of complications of undergoing the AF ablation track. The AF-TRACK calculator is a validated, easy-to-use, Web-based clinical tool to calibrate the risk-to-benefit ratio of this treatment strategy.

Influence of the anatomic characteristics of the pulmonary vein ostium, the learning curve, and the use of a steerable sheath on success of pulmonary vein isolation with a novel multielectrode ablation catheter

AIMS

Anatomic variability of the pulmonary vein (PV) ostium may adversely affect isolation rates with the circular fixed-size pulmonary vein ablation catheter (PVAC). We wanted to assess the influence on PV isolation rates of anatomic characteristics of the ostium, increasing experience of four different operators, and additional use of a steerable sheath.

METHODS AND RESULTS

In the first 190 patients (pts) undergoing PVAC ablation, minimum/maximum diameter, area and shape of the PV ostia, and the length of a common ostium were analysed from computed tomography 3D reconstructions of the left atrium and related to isolation rates. In addition, a comparison was drawn between pts at the beginning and after completion (isolation of all PVs in ≥ 85% of pts) of the learning curve, and the effect of a steerable sheath was assessed. Pulmonary vein isolation was achieved with the PVAC alone in 85% of pts and in 94% of veins after a median procedure and ablation time of 154 [interquartile ranges (IQR): 120, 200] and 51 (IQR: 38, 70) min. An increase in isolation rates was observed after the first 60 pts (73 vs. 90% of pts; P< 0.01; 88 vs. 96% of PVs; P< 0.001), coincident with routine use of a steerable sheath. Anatomic characteristics (larger minimum diameter and area) identified unsuccessful isolation only of the left inferior PV at the beginning of the learning curve.

CONCLUSIONS

Pulmonary vein isolation rates using this catheter are high. Anatomic variability of PV ostia modestly affects PV isolation rates. Standard use of a steerable sheath plays a major role in increasing isolation rates and overcoming 'difficult' anatomies.

[Catheter ablation of atrial fibrillation. Pulmonary vein isolation by using a new multipolar ablation catheter]

Catheter ablation of atrial fibrillation (AF) is an established therapeutical option, particularly in treatment of paroxysmal atrial fibrillation. This paper presents the results of using the PVAC multi-electrode ablation catheter (PVAC®, Medtronic Ablation Frontiers, Carlsbad, CA, USA). In 253 patients with paroxysmal or persistant AF, 1051 pulmonary veins were isolated, including ablation of 34 left common ostia and 1 right common ostium. Except one vein, all pulmonary veins in all patients were successfully isolated. In 23 patients with documented typical atrial flutter, the right atrial isthmus was additionally ablated within the same procedure. Follow-up (FU) visits were performed after 1, 3, 6 and 12 months with 12-lead-ECG, 24h-Holter-ECG and 4-days-Holter ECG. Mean FU was 11 ± 7 months with 1.1 interventions per patient (24 redo cases). During FU, 122 of 181 patients with paroxysmal AF (69%) and 23 of 40 patients with persistant AF (58%) were in stable sinus rhythm (SR) after ablation. 159 (62.8%) patients wer under antiarrhythmic drugs after ablation, 214 (84.5%) patients with additional β-blockers. Total procedure time was 71 ± 19 min, and total fluoroscopy time was 16 ± 6 min. In 3 cases (1.2%) procedure-related complications occured. Pulmonary vein isolation by using the PVAC-ablation catheter is a safe and effective method in treatment of paroxysmal and persistant AF.