Additional cryoapplications at the pulmonary vein antrum using a 28-mm second-generation cryoballoon: a pilot study of extra-pulmonary vein ablation.

Isolation areas post-28-mm cryoballoon pulmonary vein isolation (CB-PVI) are smaller than post-radiofrequency PV antrum isolation at the left superior PV (LSPV) antrum and recurrent atrial fibrillation (AF) can originate from this area. This pilot study evaluated the impact of additional extra-PV CB applications at the LSPV antrum following conventional CB-PVI. Eighteen paroxysmal AF patients underwent CB-PVI with single 3-min freeze techniques. Following the CB-PVI, 2-min CB applications were added once or twice at the LSPV antrum. Before and after extra-PV ablation, left atrial (LA) 3-D electroanatomical maps were created. Seventy-two total PVs were successfully isolated with 4.2 ± 0.4 applications/patient with 28-mm CBs. The mean LA posterior wall (LAPW) and non-isolated LAPW areas were 14.9 ± 3.6 and 6.9 ± 2.8 cm, respectively. After 1.6 ± 0.5 mean extra-PV applications, the upper non-isolated LAPW area significantly decreased from 3.3 ± 1.8 to 2.5 ± 1.8 cm (p < 0.001). The lowest esophageal temperatures during the extra-PV ablation were 27 °C. The total procedure and fluoroscopic times were 72.8 ± 13.1 and 15.2 ± 5.9 min, respectively. Silent gastric hypomotility was detected in 2/9 patients 1 day later, and mild PV stenosis was observed in 4/72 PVs 3 months later, but did not progress. At 12-month after single procedures, 16 (88.9%) patients were free from recurrent AF off antiarrhythmic drugs. A median of 8.0 [6.0-10.0] months later, PV reconnections were detected in 3/12 (25.0%) PVs. The non-isolated LAPW area was significantly larger in the chronic than acute phase (14.3 ± 5.2 cm, p = 0.016). This pilot study suggested the potential feasibility of additional LSPV antral cryoapplications following a conventional CB-PVI. The strategy warrants further study in more patients.