Pulsed-field noninferior to thermal ablation in treating paroxysmal atrial fibrillation

1. In this randomized noninferiority trial, pulsed-field ablation was noninferior to thermal ablation in the treatment of patients with drug-refractory paroxysmal atrial fibrillation. 

2. Both pulsed field ablation and thermal ablation had comparative rates of device- and procedure-related serious adverse events.

Evidence Rating Level: 1 (Excellent)

Study Rundown: Catheter ablation is an increasingly used, effective treatment for drug-resistant atrial fibrillation. Conventional techniques include the use of radiofrequency or cryothermal energy to isolate the pulmonary veins, an important source of arrhythmogenic foci. Recent studies have shown that pulsed field ablation, a newer approach that utilizes microsecond high-voltage electrical fields, may limit damage to the tissues outside the myocardium, which is often seen with the aforementioned thermal ablation methods. This study aimed to compare the efficacy and safety of pulsed-field ablation to conventional thermal ablation in the treatment of paroxysmal atrial fibrillation. Overall, it demonstrated that pulsed field ablation was noninferior to thermal ablation with respect to the primary efficacy endpoint of freedom from a composite of initial procedure failure, documented atrial tachyarrhythmia following a three-month blanking period, antiarrhythmic use, repeat ablation, or cardioversion. Moreover, it showed that both techniques had similar rates of device- and procedure-related serious adverse events. This study utilized a single pulsed field ablation system to treat patients with paroxysmal atrial fibrillation, and thus, the applicability of its results to other pulsed field catheters or to patients with non-paroxysmal atrial fibrillation is limited.

Click to read the study in NEJM

Relevant Reading: Hope, Hype, and Reality of Pulsed Field Ablation for Atrial Fibrillation

In-Depth [randomized controlled trial]: The ADVENT trial is a randomized, single-blind, noninferiority trial that aimed to compare the efficacy of pulsed-field ablation to thermal ablation in the treatment of drug-resistant paroxysmal atrial fibrillation. Patients 75 years of age or younger with symptomatic paroxysmal atrial fibrillation refractory to at least one antiarrhythmic medication were randomly assigned in a 1:1 ratio to undergo pulsed field ablation or thermal ablation. Following the procedure, patients were followed for one year with scheduled telephone calls and in-office visits and permitted to take antiarrhythmics during the three-month blanking period. The primary efficacy endpoint was defined as freedom from a composite of failure of the procedure to achieve pulmonary vein isolation, documented atrial tachyarrhythmia lasting 30 seconds or longer following the blanking period, antiarrhythmic use or cardioversion following the blanking period, or repeat ablation within one year, with a prespecified noninferiority margin of 15%. The primary safety outcome was defined as a composite of device- and procedure-related serious adverse events including death, pulmonary vein stenosis, and atrioesophageal fistula, among others, with a noninferiority margin of 8%. After one year, the estimated probability of treatment success was 73.3% and 71.3% for pulsed-field ablation and thermal ablation, respectively. The estimated incidence of device- or procedure-related serious adverse events was 2.1% and 1.5% for pulsed-field ablation and thermal ablation, respectively, suggesting that pulsed field ablation was noninferior to thermal ablation with respect to the aforementioned safety outcome. In summary, this study demonstrated that pulsed field ablation was noninferior to conventional thermal ablation in the treatment of drug-resistant paroxysmal atrial fibrillation.

Image: PD

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