INTRODUCTION Balloon-expandable (BE) and self-expandable (SE) prostheses are the main types of devices currently used in transcatheter aortic valve implantation (TAVI). Despite the different designs, clinical practice guidelines do not make any specific recommendation on the selection of one device over the other. Most operators are trained in using both BE and SE prostheses, but operator experience with each of the two designs might influence patient outcomes. The aim of this study was to compare the immediate and mid-term clinical outcomes during the learning curve in BE versus SE TAVI. METHODS The transfemoral TAVI procedures performed in a single center between July 2017 and March 2021 were grouped according to the type of implanted prosthesis. The procedures in each group were ordered according to the case sequence number. For each patient, a minimum follow-up time of 12 months was required for inclusion in the analysis. The outcomes of the BE TAVI procedures were compared with the outcomes of the SE TAVI procedures. Clinical endpoints were defined according to the Valve Academic Research Consortium 3 (VARC-3). RESULTS The median follow-up time was 28 months. Each device group included 128 patients. In the BE group, case sequence number predicted mid-term all-cause mortality at an optimal cutoff value ≤58 procedures (AUC 0.730; 95% CI: 0.644-0.805; p < 0.001), while in the SE group, the cutoff value was ≤85 procedures (AUC 0.625; 95% CI: 0.535-0.710; p = 0.04). A direct comparison of the AUC showed that case sequence number was equally adequate in predicting mid-term mortality, irrespective of prosthesis type (p = 0.11). A low case sequence number was associated with an increased rate of VARC-3 major cardiac and vascular complications (OR 0.98 95% CI: 0.96-0.99; p = 0.03) in the BE device group, and with an increased rate of post-TAVI aortic regurgitation ≥ grade II (OR 0.98; 95% CI: 0.97-0.99; p = 0.03) in the SE device group. CONCLUSIONS In transfemoral TAVI, case sequence number influenced mid-term mortality irrespective of prosthesis type, but the learning curve was longer in the case of SE devices.

中文翻译：

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学习曲线对球囊扩张与自扩张经股经导管主动脉瓣植入临床结果的影响。

简介 球囊扩张式 (BE) 和自扩张式 (SE) 假体是目前经导管主动脉瓣植入 (TAVI) 中使用的主要装置类型。尽管设计不同，但临床实践指南并未就选择一种设备而不是另一种设备提出任何具体建议。大多数操作员都接受过使用 BE 和 SE 假肢的培训，但操作员对这两种设计的经验可能会影响患者的治疗效果。本研究的目的是比较 BE 与 SE TAVI 学习曲线期间的近期和中期临床结果。方法 2017 年 7 月至 2021 年 3 月期间在单一中心进行的经股动脉 TAVI 手术根据植入假体的类型进行分组。每组的程序按照病例序列号排序。对于每位患者，至少需要 12 个月的随访时间才能纳入分析。BE TAVI 手术的结果与 SE TAVI 手术的结果进行了比较。临床终点根据 Valve 学术研究联盟 3 (VARC-3) 定义。结果 中位随访时间为 28 个月。每个设备组包括 128 名患者。在BE组中，病例序列号以最佳临界值≤58次手术预测中期全因死亡率（AUC 0.730；95% CI：0.644-0.805；p < 0.001），而在SE组中，临界值则为≤85 例手术（AUC 0.625；95% CI：0.535-0.710；p = 0.04）。AUC 的直接比较表明，无论假体类型如何，病例序列号同样足以预测中期死亡率（p = 0.11）。在 BE 装置组中，低病例序列号与 VARC-3 主要心脏和血管并发症发生率增加相关（OR 0.98 95% CI：0.96-0.99；p = 0.03），并且与 TAVI 后发生率增加相关SE 装置组主动脉瓣反流≥ II 级（OR 0.98；95% CI：0.97-0.99；p = 0.03）。结论 在经股 TAVI 中，无论假体类型如何，病例序列号都会影响中期死亡率，但 SE 装置的学习曲线更长。