[Impact factors of in-stent restenosis following successful stent implantation for acquired severe pulmonary vein stenosis post atrial fibrillation ablation].

To investigate the influencing factors of in-stent restenosis (ISR) following successful stent implantation in patients with ablation-associated severe pulmonary vein stenosis (PVS) who undergo atrial fibrillation ablation. Data of patients who underwent pulmonary vein angiography to confirm PVS after radiofrequency ablation for atrial fibrillation (AF) and received pulmonary vein stenting at Shanghai Chest Hospital from March 2010 to December 2017 were retrospectively analysed. All patients were followed up for a long period of time (pulmonary vein contract-enhanced CT within 6 to 12 months after operation was performed, and pulmonary angiography was performed if CT indicated stenosis>50%). The incidence of ISR was recorded. According to angiography, the patients were divided into ISR group and non-ISR group. The clinical and intraoperative imaging characteristics and interventional data were compared between the two groups. Logistic regression was used to analyse the influencing factors of ISR. A total of 47 patients ((47.1±12.2) years old) were enrolled in this study, including 28 males(59.6%). There were 19 cases in ISR group and 28 cases in non-ISR group. Compared with the non-ISR group, the ISR group received more pulmonary vein isolation ((2.8±0.9) vs. (1.8±1.3), 0.02), and the interval between last ablation and stenting was longer ((19.4±9.6) vs. (13.0±12.4), 0.03). The incidence of ISR in patients with stent diameter≤8 mm was significantly higher than those with stent diameter8 mm (33.3%(20/60) vs. 8.1%(3/37), 0.01). Logistic regression analysis found that the number of radiofrequency ablation1 (2.1, 95 1.3-3.9, 0.02), and the time from the last ablation to stent placement12 months (1.5, 95 1.1-2.5, 0.03), reference diameter of stenosed distal vessel (0.7, 95 0.5-0.9, 0.04), post procedural minimal luminal diameter (0.4, 95 0.2-0.8, 0.02) and stent diameter (0.6, 95 0.3-0.9, 0.03) were independent factors of ISR. The greater number of radiofrequency ablations and the longer time from the last ablation to stent placement increase the risk of ISR. The larger reference diameter of the stenosed distal vessel, stent diameter and post procedural minimal luminal diameter are the protective factors of ISR.