Rajesh Kabra, Matthew McKillop, Aaditya Vora, Saumil Oza, Devi G Nair, Dilip Mathew, Douglas Darden, Dhanunjaya R Lakkireddy, STAR Apollo Study Investigators
In recurrent persistent AF after prior PVI, STAR Apollo-guided redo ablation was feasible and safe, added a modest mapping step, and was associated with sinus rhythm and symptom improvement in most patients at 12 months. Designed as a feasibility and safety study, and being single-arm, these data cannot establish the incremental efficacy of STAR guidance; the encouraging rhythm outcomes are hypothesis-generating and support a randomized comparison with PV re-isolation alone.
BACKGROUND: Redo ablation for persistent atrial fibrillation (AF) that recurs after pulmonary vein isolation (PVI) has limited durable success, and adjunctive substrate strategies have not consistently improved outcomes. The STAR Apollo™ Mapping System (Rhythm AI Ltd) is an FDA-cleared technology that applies stochastic trajectory analysis of ranked signals to identify repetitive patterns of activation (RPAs) and early sites of activation (ESAs) that may indicate regions sustaining AF.
OBJECTIVE: To examine the procedural feasibility and safety, and to describe the 12-month rhythm outcomes, of STAR Apollo-guided redo ablation in patients with recurrent persistent AF after prior PVI.
METHODS: In this prospective, multicenter, observational study, patients with persistent AF recurring after one prior PVI (prior extra-pulmonary-vein ablation excluded) underwent pulmonary vein re-isolation, STAR Apollo mapping, and operator-directed adjunctive ablation. Because STAR mapping requires ongoing AF, the analysis was confined to the 50 patients (of 64 enrolled) in whom a STAR map was obtained; the 14 without a STAR map, because they were not in AF at the procedure, were excluded. Procedural parameters, safety, and rhythm at the 3-, 6-, and 12-month visits were recorded.
RESULTS: All 50 patients had one prior PVI and recurrent persistent AF; they were 68.8 ± 8.7 years of age, 35 (70.0%) male, with body-mass index 31.3 ± 5.5 kg/m2. Pulmonary vein reconnection was found and re-isolated in 46/50 (92.0%). The system identified a median of 3 (2-3) ESAs per patient, and STAR mapping added a median of 16 (13-21) minutes to a median total procedure of 125 (91-166) minutes. Sinus rhythm was restored without cardioversion in 23/50 (46.0%; AF terminated during ablation in 19/50 [38.0%] and spontaneously in 4/50 [8.0%]); 26/50 (52.0%) required cardioversion and 1/50 (2.0%) was not restored in the laboratory. Adjunctive lines included a roof line in 30/50 (60.0%) and a mitral isthmus line in 11/50 (22.0%). A procedural complication occurred in 1/50 (2.0%) (pericardial effusion). Among 40 patients assessed at 12 months, 33 (82.5%) were in sinus rhythm and symptom class improved to EHRA I in 23/30 (76.7%). By Kaplan-Meier estimation (single procedure; recurrence, repeat ablation or cardioversion counted as failure), freedom from AF was 95.3% (95% CI 82.5-98.8) at 6 months and 75.3% (95% CI 59.0-85.9) at 12 months.
CONCLUSION: In recurrent persistent AF after prior PVI, STAR Apollo-guided redo ablation was feasible and safe, added a modest mapping step, and was associated with sinus rhythm and symptom improvement in most patients at 12 months. Designed as a feasibility and safety study, and being single-arm, these data cannot establish the incremental efficacy of STAR guidance; the encouraging rhythm outcomes are hypothesis-generating and support a randomized comparison with PV re-isolation alone.