First-in-human concomitant nanosecond pulsed field ablation of atrial fibrillation
B Maesen, G Dunnington, A Driessen, L Aerts, T Mandigers, N Ad, B Van PutteAbstract
Background
In the past few years pulsed field ablation (PFA) has rapidly evolved as an alternative energy source in catheter-based ablation given its efficacy and safety profile. However, the use of PFA in surgical ablation of atrial fibrillation (AF) in concomitant cardiac surgical procedures has never been studied in humans. Nanosecond PFA (nsPFA) is a novel, nonthermal energy modality that ablates cells by initiating regulated cell death. A preclinical study with the nsPFA clamp showed 100% transmural lesions in a porcine model.
Purpose
This first-in-human feasibility trial studied the safety and efficacy of nsPFA application using bipolar surgical ablation clamps (see Figure) to perform posterior wall (PWI) and pulmonary vein isolation (PVI) for AF treatment during concomitant cardiac surgical procedures.
Methods
In AF patients undergoing cardiac surgery, left and right PVI and roof and floor lesions (box lesion) were performed (see Figure). Following elaborated animal experimentation, 2 different doses of nsPFA were tested during this feasibility study: a "low" dose and "high" dose, with variations in electric field intensity and duration of the ablation application. Acute bidirectional block of all PVs and the box was tested. Confirmation of long-term PV and box isolation was evaluated with transvenous electroanatomical mapping (EAM) at 60-120 days. During follow-up, 24-hour holter monitoring was performed at 6 and 12 months. The primary and secondary safety endpoint was defined as the rate of acute major adverse events (MAEs) and events within 30 days postoperatively.
Results
Across 3 centers in the Netherlands, 43 AF patients (paroxysmal 56%, persistent 21%, long-standing Persistent 23%) have been included. Patient demographics are summarized in Table. The average total ablation time was 43.4±25s with an average number of applications of 13.9±6. To date, EAM was completed in 27 patients (7 low dose, 20 high dose). Acute bidirectional block of PVI and PWI was 100% for the high dose cohort. EAM in the high dose patients (20/27) showed persistent PVI in 94% (75/80) per vein and 80% (16/20) per patient. For PVI + PWI, EAM showed persistent isolation in 75% (15/20, see Figure for example). In the closed box group, EAM showed persistent isolation in 87% (13/15). At 6m follow-up, 88% (22/25) were free from ATA. No device-related SAEs and no esophageal tissue or phrenic nerve damage were reported
Conclusion
In this first-in-human feasibility trial using the nsPFA surgical clamp was found to be safe with no device related complications. This is the first study to include electro-anatomical mapping in concomitant surgical ablation as part of the primary efficacy endpoint. The study demonstrated durable isolation of the left atrial "box" lesion set for the high dose protocol. The reproducibility and ultrafast ablation times have the potential to reduce pump and cross-clamp time in concomitant surgical ablation procedures.Table Patient DemographicsSurgical ablation, EAM and nsPFA clamp