From Quebec Heart and Lung Institute, Laval University, Quebec City, Canada (O.A.-J.A., R.P., A.R., C.C., T.R.-G., M.d.T., F.C.-P., T.C., M.C., J.-M.P., R.D., D.D., S.M., E.D., J.R.-C.); Department of Medicine, University of Adelaide, Australia; Cleveland Clinic Coordinating Center for Clinical Research, OH (R.P.); and Epidemiology Unit of the Cardiology Department, Vall d'Hebron Hospital, Barcelona, Spain (J.R.M.).
Circulation. 2017 Aug 15;136(7):632-643. doi: 10.1161/CIRCULATIONAHA.116.026349. Epub 2017 Jun 6.
At present, there are no objective data specifically examining the clinical impact of variations in exercise capacity post-transcatheter aortic valve replacement (TAVR). We describe the changes in exercise capacity between baseline and 6 months post-TAVR, and ascertain factors associated with and clinical implications of a lack of improvement in exercise capacity post-TAVR.
A total of 305 patients (mean age, 79±9 years; 44% men; Society of Thoracic Surgeons predicted risk mortality score, 6.7±4.2%) undergoing TAVR completed both baseline and follow-up exercise capacity assessments at 6 months post-TAVR. Exercise capacity was evaluated by the 6-minute walk test (6MWT). Clinical outcomes were compared between patients displaying greater than (n=152; improving group) versus less than (n=153; nonimproving group) the median percentage change in distance walked between baseline and 6-month follow-up examinations. The primary outcome measure was clinical event rates, measured from the 6-month post-TAVR period onward. Further dichotomization according to baseline 6MWT distance (less than versus more than median walking distance, or slow walker versus fast walker) was also assessed.
The mean overall distances walked pre- and post-TAVR (6 months post-TAVR) were 204±119 and 263±116 m, respectively (Δ6MWT=60±106 m), with 219 (72%) patients demonstrating an increase in their walking distance (median percentage increase of the entire population was 20% [interquartile range, 0%-80%]). Factors independently correlated with reduced exercise capacity improvement included a range of baseline clinical characteristics (older age, female sex, chronic obstructive pulmonary disease; <0.05 for all), periprocedural major or life-threatening bleeding (=0.009) and new-onset anemia at 6 months post-TAVR (=0.009). Failure to improve the 6MWT distance by at least 20% was independently associated with all-cause mortality (=0.002) and cardiovascular death or rehospitalization for cardiovascular causes (=0.001). Baseline slow walkers who were able to improve the 6MWT distance presented with significantly better outcomes than nonimprovers (=0.01 for all-cause mortality; =0.001 for cardiovascular end point).
Approximately one-third of patients undergoing TAVR did not improve their exercise capacity postprocedure. The lack of functional improvement post-TAVR was predicted by a mix of baseline and periprocedural factors translating into poorer clinical outcomes. These results suggest that systematically implementing exercise capacity assessment pre- and post-TAVR may help to improve patient risk stratification.
目前，尚无客观数据专门评估经导管主动脉瓣置换术（TAVR）后运动能力的临床影响。我们描述了基线和 TAVR 后 6 个月之间运动能力的变化，并确定了与 TAVR 后运动能力无改善相关的因素及其临床意义。
共 305 例患者（平均年龄 79±9 岁；44%为男性；胸外科医师协会预测死亡率评分 6.7±4.2%）在 TAVR 后 6 个月完成基线和随访时的运动能力评估。运动能力通过 6 分钟步行试验（6MWT）进行评估。比较基线和 6 个月随访检查之间步行距离中位数百分比变化大于（n=152；改善组）和小于（n=153；非改善组）的患者的临床结局。主要观察指标为从 TAVR 后 6 个月开始测量的临床事件发生率。根据基线 6MWT 距离（步行距离低于或高于中位数，或慢行者与快行者）进一步进行二分法评估。
TAVR 前后（TAVR 后 6 个月）的平均总体步行距离分别为 204±119 和 263±116 m（6MWTΔ=60±106 m），219 例（72%）患者的步行距离增加（整个人群的中位百分比增加为 20%[四分位距，0%-80%]）。与运动能力改善减少相关的独立因素包括一系列基线临床特征（年龄较大、女性、慢性阻塞性肺疾病；所有 P<0.05）、围手术期重大或危及生命的出血（=0.009）和 TAVR 后 6 个月新发生的贫血（=0.009）。6MWT 距离至少增加 20%的改善未能独立与全因死亡率（=0.002）和心血管死亡或因心血管原因再住院（=0.001）相关。基线慢行者能够改善 6MWT 距离，其结果明显优于非改善者（全因死亡率：=0.01；心血管终点：=0.001）。
约三分之一接受 TAVR 的患者术后运动能力无改善。TAVR 后缺乏功能改善可预测为基础和围手术期因素的组合，导致临床结局较差。这些结果表明，系统地在 TAVR 前后进行运动能力评估可能有助于改善患者风险分层。
