A Novel Temperature-Controlled Radiofrequency Catheter Ablation System Used to Treat Patients With Paroxysmal Atrial Fibrillation

Abstract

Objectives: DIAMOND-AF (DiamondTemp™ Ablation System for the Treatment of Paroxysmal Atrial Fibrillation) was a prospective, multicenter, noninferiority, randomized trial that compared the safety and effectiveness of the DTA system versus those of a force-sensing RF ablation system (control) for the treatment of patients with drug-refractory, recurrent, symptomatic paroxysmal atrial fibrillation (AF).

Background: Irrigated radiofrequency (RF) ablation catheters lose tissue temperature acuity, which is vital in assessing lesion formation. DiamondTemp Ablation (DTA) was designed to re-establish accurate tissue temperature measurements during ablation.

Methods: A total of 482 patients with paroxysmal AF were randomized (239 DTA, 243 control) to undergo pulmonary vein isolation and were followed up at 23 sites. Patients were screened for disease progression, cardiac characteristics, and prior interventions. Primary endpoints were effectiveness (freedom from atrial arrhythmia recurrence) and safety (composite of procedure- and device-related serious adverse events).

Results: The primary safety event rate was 3.3% in the DTA group versus 6.6% in the control group (p < 0.001 vs. 6.5% noninferiority margin). Primary effectiveness was met in 79.1% of DTA subjects and 75.7% of control subjects (p < 0.001 vs. -12.5% noninferiority margin). Secondary endpoint analysis found that off-drug effectiveness favored DTA compared with the control (142 [59.4%] vs. 120 [49.4%], respectively; p = 0.03). Total RF time and individual RF ablation duration were significantly shorter with less saline infused through the DTA catheter (p < 0.001). Both arms saw clinically meaningful improvements in quality of life at 12 months.

Conclusions: Safety and efficacy of the DTA system proved noninferior to force-sensing RF ablation in a paroxysmal AF population. Efficiencies were observed using DTA with shorter total RF times, individual RF ablation durations, and less saline infusion. (DiamondTemp™ Ablation System for the Treatment of Paroxysmal Atrial Fibrillation; NCT03334630).

Keywords: DiamondTemp; atrial fibrillation; catheter ablation; contact force; radiofrequency.

Conflict of interest statement

Funding Support And Author Disclosures This study was sponsored by Epix Therapeutics, Inc., which was acquired by Medtronic, Inc. in March 2019. Dr. Kautzner has received consultancy services from Biosense Webster, Medtronic, and Merit Medical; and has received speaker honoraria from Abbott, Biosense Webster, Biotronik, and Medtronic. Dr. Albenque has received consultancy services from Biosense Webster and Abbott. Dr. Natale has received consultancy services from Biosense Webster, Boston Scientific, Medtronic, Biotronik, Abbott, and Baylis. Dr. Maddox has received consultancy services from Abbott, ACT, Biosense Webster, Boston Scientific, and Medtronic; and has received speaker honoraria fees from Biosense Webster and Boston Scientific. Dr. Cuoco has received consultancy services from Medtronic. Mr. Getman and Ms. Liu are employed by and are stockholders of Medtronic. Dr. Dukkipati has received research grants from Biosense Webster. Dr. Colley reports no relationships with industry beyond that of the funding in support of this study from Epix Therapeutics. Dr. Al-Ahmad has received honoraria from Abbott, Biosense Webster, Boston Scientific, and Medtronic. Dr. Sidney has provided consultancy services for Janssen (J&J), Abbott, and Boston Scientific. Dr. McElderry has provided consultancy and has financial interest in Farapulse; and has provided consultancy and research in Medtronic/EPIX, Biosense Webster, and Boston Scientific. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose.

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