Does second-generation cryoballoon ablation using the current single short freeze strategy produce pulmonary vein stenosis?

Background: Few data are available regarding pulmonary vein (PV) stenosis after second-generation cryoballoon PV isolation (CB2-PVI). Currently, a single short freeze strategy is standard for CB2-PVI owing to enhanced cooling effects. This study aimed to evaluate the incidence of PV stenosis after CB2-PVI with the current standard strategy. Methods: Two hundred seventy-six atrial fibrillation patients underwent CB2-PVI using one 28-mm balloon and single 3-minute freeze strategy. If balloon temperatures reached -60 degrees C or phrenic nerve injury was suspected, freezing was terminated. Enhanced cardiac computed tomography (CT) was obtained before and >3 months after the procedure. Results: Overall, 1067 of 1101 (96.9%) PVs were isolated with cryoballoons, while the remaining 34 PVs required touch-up ablation. The total application number/patient was 5.1 +/- 1.4, and total application time 216 +/- 104, 205 +/- 77, 186 +/- 68, and 246 +/- 142 s for the left superior (LSPV), left inferior (LIPV), right superior (RSPV), and right inferior PVs, respectively. Follow-up CT obtained a median of 5.0 [3.3-7.0] months post-procedure revealed no PVs with moderate or severe stenosis. Asymptomatic mild stenosis was documented in 16 total (1.4%) PVs (5 LSPVs, 5 LIPVs, and 6 RSPVs), but not in right inferior, left common, right middle, or PVs requiring touch-up ablation. Mild stenosis did not progress during the follow-up. Among the potential factors associated with PV stenosis, longer application times were the sole significant factor associated with mild RSPV stenosis. Conclusions: In CB2-PVI with the current single short freeze strategy, the risk of PV stenosis is extremely low, and routine follow-up imaging for evaluation seems not to be necessary. (C) 2018 Published by Elsevier B.V.