Substrate Versus Trigger Ablation for Paroxysmal Atrial Fibrillation
- Conditions
- Atrial Fibrillation
- Interventions
- Procedure: FIRM AblationProcedure: Conventional AF ablation with PVI
- Registration Number
- NCT02169037
- Lead Sponsor
- University of California, San Diego
- Brief Summary
This is a prospective randomized study to assess the safety and efficacy of FIRM (Focal Impulse and Rotor Modulation)-guided ablation for the treatment of symptomatic atrial fibrillation (AF). The study hypothesis is that the efficacy of AF elimination at 1 year will be higher by ablating patient-specific AF-sustaining rotors and focal sources by Focal Impulse and Rotor Modulation (FIRM) compared to conventional ablation alone (wide-area PV isolation).
- Detailed Description
Pulmonary vein isolation (PVI) is a standard of care therapy for atrial fibrillation (AF). However, it produces suboptimal results, with a single procedure success of 45-55%, and multiple procedure success rates of 65-75% in recent randomized trials. The rationale of PVI is to eliminate triggers from the Pulmonary veins. An alternative strategy is to eliminate the substrates that sustain AF after it has been triggered, as applied to other arrhythmias. However, the relevance of AF substrates - at least in persistent AF - has been questioned with the recent STAR-AF-II trial, in which ablating at additional lines or complex atrial electrograms (CFAE) did not improve the success of PVI alone (Verma et al., 2015) - although success remained at \~50% for a single procedure. Because of STAR-AF2, the PVI limb in this trial will be PVI alone (wide area circumferential ablation) with no additional lesions.
Focal Impulse and Rotor Modulation (FIRM) is a novel approach to eliminate specific electrical substrates for AF, demonstrated in studies from many laboratories to take the form of localized electrical circuits. These rotors and focal sources lie in patient-specific locations, often away from typical PVI ablation sites and in right atrium, and ablating them has substantially improved the single procedure success rate of PVI in several multi center non-randomized trials (Narayan, J Am Coll Cardiol. 2012; Miller, J Cardiovasc Electrophysiol. 2014).
There is therefore equipoise in the literature between PVI alone, with a long-history but suboptimal results, and FIRM only, that is newer with potentially greater efficacy but without randomized trial data.
This study will test both strategies in a randomized controlled fashion.
Recruitment & Eligibility
- Status
- UNKNOWN
- Sex
- All
- Target Recruitment
- 120
Not provided
Not provided
Study & Design
- Study Type
- INTERVENTIONAL
- Study Design
- PARALLEL
- Arm && Interventions
Group Intervention Description FIRM ablation FIRM Ablation These patients will be treated by ablation of patient-specific rotors and focal sources (FIRM) alone. Conventional AF ablation with PVI Conventional AF ablation with PVI These patients will treated by conventional AF ablation by pulmonary vein isolation (PVI) alone.
- Primary Outcome Measures
Name Time Method Long term success 12 months Freedom from AF recurrence during 12 months after the initial AF ablation procedure, after an initial 3 month blanking (healing and stabilization) period
- Secondary Outcome Measures
Name Time Method Long-term freedom from AF/AT 12 months Freedom from AF and atrial tachycardia (AT) during 12 months after the initial AF ablation procedure, after an initial 3 month blanking (healing and stabilization) period. Atrial tachycardias (AT) include those arising from atrial regions where ablation was performed (such as left atrial tachycardia) as well as from regions where ablation was not performed (such as typical cavotricuspid isthmus dependent atrial flutter).
Total ablation time 1 day Time from first ablation lesion to the last lesion. Total ablation time will be recorded in all patients, measured as the cumulative application of energy from the first ablation lesion to the last lesion. These values will be compared between the FIRM-guided and conventional ablation groups. If ablation for AT/atrial flutter is pursued, this ablation time will be documented separately.
Quality of life (QOL) 12 months Quantitative EuroQol EQ5D scores post-ablation will be compared to those pre-ablation at all time points separately and together (ANOVA).
Adverse events 12 months Adverse events will be adjudicated by an independent Data and Safety Monitoring Board, who will determine whether they are or are not related to the procedure. The number and type of adverse events will be compared between FIRM-guided and conventional ablation groups.
Consistency of Sources At Repeat Ablation 2 years Any patient with a recurrence who consents to restudy will have an assessment of whether rotors and focal sources lie at the same locations as they did at original study.
Trial Locations
- Locations (2)
VA San Diego Medical Center
🇺🇸San Diego, California, United States
Stanford University
🇺🇸Palo Alto, California, United States