PO-695-08 PULMONARY VEIN ISOLATION (PVI) AND POSTERIOR WALL ISOLATION (PWI) FOR ATRIAL FIBRILLATION USING POINT-BY-POINT PULSED ELECTRIC FIELDS: SPACE AF ACUTE RESULTS

Abstract

Pulsed electrical field (PEF) has been used for pulmonary vein isolation (PVI). The CENTAURI System enables PEF ablation via standard contact force ablation catheters. The point-by-point clinical workflow may enable treatment beyond PVI, including posterior wall isolation (PWI). SPACE AF study is evaluating feasibility and safety of PVI with PWI using PEF in patients with high burden paroxysmal and persistent AF. CENTUARI PEF System (Galaxy Medical) and a focal contact force sensing catheter (ThermoCool ST, Biosense Webster) were used for PEF ablation for wide antral PVI with PWI. Operators chose one of three doses (19A, 22A, 25A) with contact force of >5g. Primary efficacy outcome was entrance/exit block of all pulmonary veins (PVs) after a 20-minute wait. Composite safety endpoint comprised of pre-specified adverse events including microbubble formation on intracardiac echo (ICE), ST-segment changes, phrenic nerve palsy, esophageal temperature rises, NIH stroke scale (NIHSS) changes, PV stenosis, and silent cerebral lesions after PEF ablation. CT of the PVs will be done at 3 months. Cranial MRI was done at 24 hours in a subset of patients. Secondary endpoint includes recurrence of AF post-ablation at 6 and 12 months with serial Holter monitoring. SPACE AF will report on 30 patients. Thus far, 12 patients (58% Male, age 55.8±10.5 years) have been treated. Acute PVI and PWI was achieved in all 12 patients (100%). An average of 113.8±12.1 applications were delivered per patient. Energy settings were 32% at 22A and 68% at 25A. There were no ST-segment changes, microbubble formations, phrenic nerve injuries, or esophageal temperature rises during PEF ablation. There were no changes to NIHSS pre- vs. post-procedure. Three (3) patients have participated in the cranial MRI sub-study, and all had negative DWI and FLAIR post-procedure. No patients experienced procedure- or device-related AEs at 30 days. PV anatomy will be assessed at 90 days. Long-term AF recurrence outcomes will be assessed at 6-month and 12-month follow-up via 48-hour Holter. Cardiac ablation using PEF delivered through standard focal catheters is safe and acutely successful when performing PWI after PVI. Further results on additional patients and AF recurrence will be presented.