Related Experiment Video
Updated: May 3, 2026
Robotic Ablation of Atrial Fibrillation
Published on: May 29, 2015
Low-Voltage Myocardium-Guided Ablation Trial of Persistent Atrial Fibrillation
Yan Huo1, Thomas Gaspar1, Robert Schönbauer2
1Department of Electrophysiology, Heart Center, Dresden University of Technology, Dresden, Germany.
Abstract:
BACKGROUND: Clinically effective ablation approaches for patients with persistent atrial fibrillation (AF) are still being debated. So far, ablation targets and strategies beyond pulmonary vein isolation (PVI) have failed to show systematic outcome improvement in randomized controlled clinical trials. METHODS: We conducted a multicenter, randomized trial to determine whether PVI plus individualized substrate ablation of atrial low-voltage myocardium improves outcome in patients with persistent AF. We randomly assigned 324 patients in a 1:1 ratio to receive PVI alone (163 patients; PVI only) or PVI plus substrate modification (161 patients; PVI+SM). The primary study end point was the first recurrence of an atrial arrhythmia longer than 30 seconds after single ablation, with 3 months blanking, using serial 7-day electrocardiogram recordings over 12 months of observation. Patients were also encouraged to receive implantable cardiac monitors. RESULTS: The primary study end point occurred in 75 PVI-only patients (50%) and in 54 PVI+SM patients (35%) (Kaplan–Meier event rate estimates: hazard ratio=0.62, 95% confidence interval [CI]=0.43 to 0.88, log rank P=0.006). Adverse events occurred in three PVI-only patients (1.8%) and in six PVI+SM patients (3.7%) (difference: −1.9 percentage points, 95% CI=−5.5 to 1.7 percentage points). Implant monitoring was used in 242 patients. Among them, 65 PVI-only patients (55%) versus 47 PVI+SM patients (39%) experienced recurrences (difference: 15 percentage points, 95% CI=3 to 28 percentage points). CONCLUSIONS: In this randomized trial, PVI plus individualized ablation of atrial low-voltage myocardium significantly improved outcomes in patients with persistent AF. (ClinicalTrials.gov number, NCT02732626.)
Insights
Adding substrate modification to pulmonary vein isolation (PVI) significantly reduced atrial arrhythmia recurrence in patients with persistent atrial fibrillation (AF). This PVI plus substrate modification strategy offers improved outcomes for AF ablation.
Area of Science:
- Cardiology
- Electrophysiology
- Medical Interventions
Background:
- Current ablation strategies for persistent atrial fibrillation (AF) beyond pulmonary vein isolation (PVI) lack consistent outcome improvement in clinical trials.
- Debate continues regarding optimal ablation targets and techniques for persistent AF.
Purpose of the Study:
- To evaluate if PVI combined with individualized substrate ablation of atrial low-voltage myocardium improves outcomes in persistent AF patients.
- To compare the efficacy of PVI alone versus PVI plus substrate modification (PVI+SM).
Main Methods:
- A multicenter, randomized trial involving 324 patients with persistent AF.
- Patients were assigned to PVI only or PVI+SM groups.
- Primary endpoint: atrial arrhythmia recurrence >30 seconds post-ablation, assessed over 12 months with ECG and implantable monitors.
Main Results:
- PVI+SM group showed significantly lower recurrence rates (35%) compared to PVI only (50%) (HR=0.62, P=0.006).
- Recurrence rates using implant monitoring were 39% for PVI+SM versus 55% for PVI only.
- Adverse events were low and comparable between groups (3.7% vs 1.8%).
Conclusions:
- Individualized substrate ablation of atrial low-voltage myocardium in addition to PVI significantly improves outcomes for persistent AF patients.
- The PVI+SM approach demonstrates superior efficacy in preventing atrial arrhythmia recurrence.
- This strategy represents a potential advancement in the treatment of persistent AF.
