Effect of MRI-Guided Fibrosis Ablation vs Conventional Catheter Ablation on Atrial Arrhythmia Recurrence in Patients With Persistent Atrial Fibrillation: The DECAAF II Randomized Clinical Trial

Abstract

Importance: Ablation of persistent atrial fibrillation (AF) remains a challenge. Left atrial fibrosis plays an important role in the pathophysiology of AF and has been associated with poor procedural outcomes.

Objective: To investigate the efficacy and adverse events of targeting atrial fibrosis detected on magnetic resonance imaging (MRI) in reducing atrial arrhythmia recurrence in persistent AF.

Design, setting, and participants: The Efficacy of Delayed Enhancement-MRI-Guided Fibrosis Ablation vs Conventional Catheter Ablation of Atrial Fibrillation trial was an investigator-initiated, multicenter, randomized clinical trial involving 44 academic and nonacademic centers in 10 countries. A total of 843 patients with symptomatic or asymptomatic persistent AF and undergoing AF ablation were enrolled from July 2016 to January 2020, with follow-up through February 19, 2021.

Interventions: Patients with persistent AF were randomly assigned to pulmonary vein isolation (PVI) plus MRI-guided atrial fibrosis ablation (421 patients) or PVI alone (422 patients). Delayed-enhancement MRI was performed in both groups before the ablation procedure to assess baseline atrial fibrosis and at 3 months postablation to assess for ablation scar.

Main outcomes and measures: The primary end point was time to first atrial arrhythmia recurrence after a 90-day blanking period postablation. The primary safety composite outcome was defined by the occurrence of 1 or more of the following events within 30 days postablation: stroke, PV stenosis, bleeding, heart failure, or death.

Results: Among 843 patients who were randomized (mean age 62.7 years; 178 [21.1%] women), 815 (96.9%) completed the 90-day blanking period and contributed to the efficacy analyses. There was no significant difference in atrial arrhythmia recurrence between groups (fibrosis-guided ablation plus PVI patients, 175 [43.0%] vs PVI-only patients, 188 [46.1%]; hazard ratio [HR], 0.95 [95% CI, 0.77-1.17]; P = .63). Patients in the fibrosis-guided ablation plus PVI group experienced a higher rate of safety outcomes (9 [2.2%] vs 0 in PVI group; P = .001). Six patients (1.5%) in the fibrosis-guided ablation plus PVI group had an ischemic stroke compared with none in PVI-only group. Two deaths occurred in the fibrosis-guided ablation plus PVI group, and the first one was possibly related to the procedure.

Conclusions and relevance: Among patients with persistent AF, MRI-guided fibrosis ablation plus PVI, compared with PVI catheter ablation only, resulted in no significant difference in atrial arrhythmia recurrence. Findings do not support the use of MRI-guided fibrosis ablation for the treatment of persistent AF.

Trial registration: ClinicalTrials.gov Identifier: NCT02529319.

Conflict of interest statement

Conflict of Interest Disclosures: Dr Marrouche reported other from Marrek (founder) and from ECG Check (previous shareholder) outside the submitted work; and a patent issued for MRI fibrosis imaging. Dr Wazni reported personal fees (for consulting services) from Biosense Webster and from Boston Scientific during the conduct of the study. Dr Greene reported personal fees from DURECT Corporation, Janssen Pharmaceuticals, and Pfizer Inc; and grants from Boeringer-Inglemeim, AstraZeneca, and CSL outside the submitted work. Dr Dean reported grants from Boston Scientific, Medtronic, Siemens, Biosense, and Abbott during the conduct of the study; and grants from the National Institutes of Health outside the submitted work. Dr Kholmovski reported personal fees and other (share ownership) from Marrek Inc during the conduct of the study and outside the submitted work; grants from Medtronic outside the submitted work; and a patent issued for US 9713436 licensed to Marrek Inc, US 10004425 licensed to Marrek Inc, and US 10726545. Dr Mansour reported personal fees (for consulting services) from Biosense Webster, Boston Scientific, and Medtronic; personal fees (holding equity) from EPD Solutions and New Pace Ltd outside the submitted work. Dr Marchlinski reported personal fees (scientific advisory board) from Abbott Medical, Biosense Webster, and Medtronic outside the submitted work. Dr Wilber reported other (executive committee for clinical trial) from Abbott and Boston Scientific; other (coprimary investigator, clinical trial) from Atricure; grants from Abbott, Atricure, and Biosense; and personal fees from the American College of Cardiology Foundation (editor-in-chief, Journal of the American College of Cardiology editor’s page), Biosense (consulting), and Medtronic (lectures for fellows) outside the submitted work. Dr Jais reported grants from Biosense Webster and Boston Scientific during the conduct of the study; and grants from Acutus and Medtronic outside the submitted work. Dr Sanders reported other (advisory board, research grants to his institution) from Medtronic, Abbott Medical, and Boston Scientific; other (advisory board) from CathRx and Pacemate outside the submitted work; and support by a practitioner fellowship from the National Health and Medical Research Council of Australia. Dr Brachmann reported grants from Medtronic and Biotronik during the conduct of the study; and personal fees from Medtronic outside the submitted work. Dr Bax reported departmental unrestricted research grants from Abbott, Edwards Lifesciences, Medtronic, Biotronik, Boston Scientific, GE Healthcare, Novartis, and Bayer outside the submitted work. Dr Deneke reported grants (education) from Biotronik; and personal fees (speaker) from Abbott and Boston Scientific (scientific committee) outside the submitted work. Dr Calkins reported personal fees from Biosense Webster, Abbott, and Boston Scientific outside the submitted work. No other disclosures were reported.

Figures

Figure 1.. Patient Evaluation and Randomization for a Trial of MRI-Guided Fibrosis Ablation for Atrial Fibrillation

aSubcategories are not mutually exclusive and may not sum because a single patient may have multiple reasons for being excluded, not randomized, or not followed-up after the blanking period. bReasons not approached: attending physician preference (n = 11), site investigator and/or research coordinator resources were inadequate to recruit additional patients (n = 3), and other (n = 83). cReasons magnetic resonance imaging (MRI) was not performed: patient noncompliance or refusal (n = 26), technical difficulties (n = 9), medical condition (n = 5), body habitus (n = 4), glomerular filtration rate too low (n = 3), insufficient time (n = 3), ablation cancelled (n = 1), and unknown (n = 11). dThere were 12 patients randomized to MRI-guided ablation who were ablated using pulmonary vein isolation (PVI) alone, and there was 1 patient randomized to PVI alone who was ablated using MRI-guided ablation. Hence the total number of patients included in safety analyses were 414 – 12 + 1 = 403 for the MRI-guided ablation group and 417 + 12 – 1 = 428 for the PVI-alone group. More than 1 reason could be designated for not receiving ablation. eThe blanking period was defined as 90 days postablation. Patients were not monitored for the primary outcome of atrial arrhythmia recurrence during this period. AF indicates atrial fibrillation.

Figure 2.. Primary Composite of Atrial Arrhythmia Recurrence or Repeat Ablation

The analysis was performed in randomized patients who remained in follow-up after the 90-day blanking period. Follow-up times are expressed in days following the end of the 90 day blanking period. No. at risk indicates the number of patients remaining at risk at the indicated follow-up times without a prior atrial arrhythmia–recurrence event. Cox model hazard ratio, 0.95 (95% CI, 0.77-1.17); log-rank P = .63; median observation time, 273 days (IQR, 51-321 days). MRI indicates magnetic resonance imaging; PVI, pulmonary vein isolation.