Abstract Background Pressure-guided cryoablation (PGC) is a contrast-free technique used to isolate Pulmonary Veins (PV) in order to treat atrial fibrillation (AF). In this technique the main goal is to achieve a wedge curve to assure adequate vein occlusion(1). As the wedge curve is not always clear, we hypothesize that the wedge pressures (systolic, diastolic and mean) could be useful as reliable surrogate markers. Purpose The aim of this study is to evaluate wedge pressures in individual vein occlusions in a cohort of patients referred for PV isolation using PGC. Methods Between February 2022 and October 2023, 23 patients (7 female, 13 paroxysmal AF) underwent PV isolation using PGC protocol. No REDOs were included. The procedure was intended to obtain PV isolation with one shot of 240 seconds. All patients underwent computed tomography angiography or MRI of LA and PV. A 28-mm Cryoballoon and a Intracardiac echo were used in all the procedures. Invasive radial arterial and LA pressures were registered. We analysed all the shots per vein and compared data between successful and unsuccessful isolation. Multivariate statistical analysis was performed, being the PV isolation the main outcome. Results There were realized 125 applications in 92 veins, being isolated 100% of them. One vein (left superior) was isolated after application in inferior ipsilateral vein, so it was considered successful as there was no need of additional applications. Eleven applications were performed as a bonus, so they were not considered for the isolated-non isolated analysis. Wedge curve was obtained in 112/119 applications (the 7 applications with not adequate wedge curve were 3 in right superior and 4 in right inferior pulmonary veins). In 5 applications the graphic curve was not reliable, but the pressure values were registered. There were significative differences in nadir temperature, systolic, diastolic and mean vein pressures, and the presence of a wedge curve. In the multivariate analysis, the nadir temperature (OR 0.79 CI95% 0.70–0.90) and the diastolic vein pressure at occlusion (OR 1.16 CI95% 1.01–1.36) were the only independent predictor factors of PV isolation. Conclusion With these results, we conclude that the monitoring of diastolic PV pressure during applications and the nadir temperature are the best markers to predict a successful isolation in the PGC.Figure 1.Pressure waveformTable 1.Application characteristics