Department of Cardiothoracic Surgery, Rutgers Health, New Brunswick, New Jersey.
Division of Cardiology, University of Washington, Seattle, Washington.
J Am Coll Cardiol. 2019 Feb 5;73(4):427-440. doi: 10.1016/j.jacc.2018.11.031.
Given conflicting findings of previous studies, much remains to be understood regarding a volume-outcomes relationship (VOR) in transcatheter aortic valve replacement (TAVR).
The purpose of this study was: 1) to determine if, after the initial learning curve (LC), a VOR for balloon-expandable (BE) TAVR persisted; and 2) to determine if LCs and VORs differed across different device generations.
Data collected by the TVT registry for BE valve implants from November 2011 through January 2017 were included in this analysis (n = 61,949). Primary outcomes included 30-day all-cause mortality, stroke, and major vascular complications. For each center, all implants were ordered chronologically according to case sequence number (CS#). To determine where the learning curve terminated (LCT), a grid search analysis was applied across a range of CS# from 10 to 300 by increments of 1. After LCT, the VOR was assessed by examining case volume/month by center. This analysis was performed separately for: 1) all BE valve types; 2) Sapien 3 (S3) only; and 3) S3 in BE valve naïve sites.
In experience with all commercially available BE valve types, there was an initial LC that terminates around case #201. After the initial LC, a volume-outcomes relationship was no longer evident. In analysis limited to S3, there was no demonstrable LC or VOR. Likewise, there was no demonstrable LC or VOR with S3 for BE valve naïve sites.
After a case experience of 200 cases, there was LCT; subsequent to initial learning, a VOR was no longer evident. In the S3-only analysis, there was no LC or no demonstrable VOR. With current-generation BE-TAVR, centers should expect to achieve consistently excellent outcomes even during early case experience.
先前的研究结果相互矛盾，经导管主动脉瓣置换术（TAVR）的容量-结果关系（VOR）仍有许多未解之谜。
本研究旨在：1）确定在初始学习曲线（LC）之后，球囊扩张（BE）TAVR 是否存在 VOR；2）确定不同器械代际之间的 LC 和 VOR 是否存在差异。
该分析纳入了 2011 年 11 月至 2017 年 1 月 TVT 注册研究中 BE 瓣膜植入的数据（n=61949）。主要结局包括 30 天全因死亡率、卒中和主要血管并发症。对于每个中心，所有植入物均根据病例序号（CS#）按时间顺序排列。为了确定学习曲线的终点（LCT），应用网格搜索分析，CS#范围从 10 到 300，增量为 1。在 LCT 之后，通过检查中心的每月病例量/月来评估 VOR。该分析分别针对：1）所有 BE 瓣膜类型；2）Sapien 3（S3）；3）BE 瓣膜初治部位的 S3 进行。
在所有市售的 BE 瓣膜类型的经验中，存在一个初始 LC，终止于病例#201 左右。在初始 LC 之后，不再存在 VOR。在仅分析 S3 的情况下，没有明显的 LC 或 VOR。同样，在 BE 瓣膜初治部位，S3 也没有明显的 LC 或 VOR。
在经历 200 例病例后，达到了 LCT；在初始学习之后，不再存在 VOR。在仅分析 S3 的情况下，没有 LC 或没有明显的 VOR。在使用当前代的 BE-TAVR 时，即使在早期病例经验中，中心也应该期望获得始终出色的结果。
