Comparative Evaluation of the Efficacy and Safety of High-Power Short-Duration Radiofrequency Ablation and Standard Low-Power Ablation in Catheter Treatment of Atrial Fibrillation

Overview

Atrial fibrillation (AF) is the most common cardiac arrhythmia and represents one of the leading causes of cardiovascular morbidity and mortality. According to current data, AF is associated with approximately 20% of all ischemic strokes, while the risk of stroke in patients with this arrhythmia is increased fivefold. Ischemic stroke in patients with AF is characterized by a more severe clinical course, more frequently results in death, is associated with significant disability, and carries a higher risk of recurrence compared with strokes of other etiologies. Consequently, the risk of death in patients with AF-associated stroke is doubled, while the economic costs of treatment increase by an average of 1.5 times. The aim of the present study is to perform a comparative evaluation of the efficacy of two interventional treatment strategies for atrial fibrillation: very high-power short-duration radiofrequency ablation (90 W) and conventional low-power radiofrequency ablation (35-45 W) for pulmonary vein isolation using the "CLOSE protocol" approach with a non-fluoroscopic navigation system. The efficacy of the interventions will be assessed both in the early postoperative period and during long-term follow-up over 12 months.

Detailed description

The study is designed to involve highly specialized centers with substantial clinical experience in the interventional treatment of atrial fibrillation (at least 300 procedures annually) and equipment enabling both conventional low-power radiofrequency ablation (35-45 W) and very high-power short-duration ablation (vHPSD) using the QMODE Plus mode (90 W) for pulmonary vein isolation performed according to the "CLOSE protocol" strategy with non-fluoroscopic navigation systems. The study population will include patients with paroxysmal and persistent forms of atrial fibrillation.

This randomized open-label controlled trial will be conducted with allocation of patients into two groups according to the interventional treatment strategy applied. In the first group, pulmonary vein isolation will be performed using conventional low-power settings (35-45 W), whereas in the second group, pulmonary vein isolation will be carried out using very high-power short-duration ablation (vHPSD) with 90 W energy delivery. Patient randomization will be performed using the sealed-envelope method with a restricted block randomization scheme (block size of 10 patients, with equal allocation of 5 patients to each group). The study is expected to be completed after enrollment of 196 patients.

Interventions

• Procedure Technique of radiofrequency ablation using very high-power short-duration ablation parameters
  Radiofrequency ablation is performed in QMODE Plus mode (90 W, 4 s per application) with esophageal temperature monitoring (not exceeding 38.5 °C), using a steerable introducer and a contact force of 5-15 g.
• Procedure Technique of radiofrequency ablation using low-power settings
  Radiofrequency ablation is performed at a power of 35 W and an application duration of 10-15 s with monitoring of the ablation index (400-550 depending on the anatomical zone), esophageal temperature (not exceeding 38.5 °C), and a contact force of 5-15 g.

Primary outcome measures

• Recurrence of AF [Time frame: From the date of ablation until the date of recurrent atrial fibrillation, assessed up to 12 months]

Secondary outcome measures (4)

• Hospital mortality [Time frame: From the date of ablation until the date of death, assessed up to 5 days]
• Non-lethal events [Time frame: From the date of ablation to the date of any of the listed events, assessed up to 5 days]
• Long-term mortality [Time frame: From the date of ablation until the date of death, assessed up to 12 months]
• Cerebral events [Time frame: From the date of ablation until the date of the event, assessed up to 12 months]

Eligibility criteria

Inclusion criteria

• Age over 18 years old;
• Atrial fibrillation resistant to antiarrhythmic therapy;
• Paroxysmal form of atrial fibrillation;
• Persistent form of atrial fibrillation;
• The patient's consent to participate in the study.

Exclusion criteria

Exclusion criteria

• Age under 18 and over 80 years old;
• The presence of another cardiac pathology requiring surgical treatment;
• Congenital heart defects;
• Previous "open" cardiac surgery;
• Bone marrow diseases;
• Pathology of the blood coagulation system;
• The left ventricular ejection fraction is less than 40%;
• Moderate to severe renal insufficiency (creatinine clearance <50 ml/min);
• Drug-resistant hypertension (despite hypotensive therapy);
• Organically altered mitral valve;
• There are reasons to assume that the patient will not show up for subsequent visits (control points of the study) for various reasons;
• The patient's participation in another clinical trial.

Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.

Healthy volunteers: No

Study design

Allocation

Randomized

Model

Parallel assignment

Masking

Single blind

Primary purpose

Treatment

Study locations

Russia · 1 center

• Bakulev National Medical Research Center for Cardiovascular Surgery — Moscow

Identifiers

NCT: NCT07728539 · #2.29.05.2025

Primary sources (government registries)

• ClinicalTrials.gov (US NIH)

View this study on ClinicalTrials.gov ↗