Pulmonary vein (PV) narrowing after atrial fibrillation (AF) ablation is a significant complication, with thermal ablation methods like radiofrequency (RF) and cryoballoon (CB) associated with more PV narrowing than pulsed field ablation (PFA). This study compared PFA with thermal ablation in a randomized trial (ADVENT) to assess PV narrowing. PFA, a non-thermal ablation method, was found to result in significantly less PV narrowing compared to thermal ablation. The study included 607 patients with paroxysmal AF, of whom 259 received PFA and 255 received thermal ablation. PV diameter and cross-sectional area were measured at baseline and 3 months post-procedure. PFA showed a smaller reduction in PV cross-sectional area (-0.9%) compared to thermal ablation (-12%), with the RF subgroup showing the most significant reduction. PFA was associated with less fibrosis and better tissue preservation, leading to less PV narrowing. The results suggest that PFA is a more favorable ablation method for minimizing PV narrowing, with potential clinical benefits in reducing long-term complications. The study highlights the qualitative differences in the effects of PFA and thermal ablation on PV tissue, supporting the use of PFA as a preferred method for AF ablation.Pulmonary vein (PV) narrowing after atrial fibrillation (AF) ablation is a significant complication, with thermal ablation methods like radiofrequency (RF) and cryoballoon (CB) associated with more PV narrowing than pulsed field ablation (PFA). This study compared PFA with thermal ablation in a randomized trial (ADVENT) to assess PV narrowing. PFA, a non-thermal ablation method, was found to result in significantly less PV narrowing compared to thermal ablation. The study included 607 patients with paroxysmal AF, of whom 259 received PFA and 255 received thermal ablation. PV diameter and cross-sectional area were measured at baseline and 3 months post-procedure. PFA showed a smaller reduction in PV cross-sectional area (-0.9%) compared to thermal ablation (-12%), with the RF subgroup showing the most significant reduction. PFA was associated with less fibrosis and better tissue preservation, leading to less PV narrowing. The results suggest that PFA is a more favorable ablation method for minimizing PV narrowing, with potential clinical benefits in reducing long-term complications. The study highlights the qualitative differences in the effects of PFA and thermal ablation on PV tissue, supporting the use of PFA as a preferred method for AF ablation.