Hybrid approach for the treatment of long-standing persistent atrial fibrillation: electrophysiological findings and clinical results.

OBJECTIVES The sequential, staged hybrid approach has recently emerged as a novel strategy for the treatment of long-standing persistent atrial fibrillation (AF); nevertheless, the potential modifications in terms of electrophysiological findings and their correlation with mid-term results have not been fully elucidated so far. METHODS Forty-five patients with long-standing persistent AF underwent a hybrid procedure combining surgical closed-chest posterior left atrium (LA) and pulmonary veins (PV) isolation (box lesion) first, followed by transcatheter evaluation at least 1 month afterwards. Electrophysiological findings and their correlation with rhythm outcomes were assessed at different time points, i.e. following the surgical ablation (T1), during (T2) and at the end (T3) of the transcatheter evaluation and at 28-month follow-up (T4). RESULTS At T1, exit and entrance blocks were achieved in 100 and 91.1% (41 of 45) of patients, respectively. At T2, the percentage of conduction block was unchanged, while at T3 also entrance block was achieved in all instances. In terms of electrophysiological findings (at T2), PV reconnection occurred in 6.7% (3 of 45) of patients, fractionated electrograms were targeted in 44.4% (20 of 45) while right atrium isthmus lesion was performed in 24.4% (11 of 45) of patients. Sinus rhythm was restored in 75.6% (34 of 45) at T1, at T2 (with AF induction) in 68.9% (31 of 45), at T3 in 93.3% (42 of 45) and at T4 in 88.9% (40 of 45) of patients, respectively. In those patients with a bidirectional block at T1, sinus rhythm restoration steadily improved from 78 (32 of 41) at T1 to 82.9 (34 of 41) at T2 and finally 92.6% (38 of 41) at T4. CONCLUSION Complete posterior LA and PV isolation with the box lesion in a staged hybrid approach is associated with incremental benefits in terms of sinus rhythm maintenance in patients with long-standing persistent AF.