Department of Radiology and Radiological Science, Division of Cardiovascular Imaging, Medical University of South Carolina, 25 Courtenay Dr, Ashley River Tower, Charleston, SC 29425-2260.
Department of Diagnostic and Interventional Radiology, University Hospital Augsburg, Augsburg, Germany.
AJR Am J Roentgenol. 2022 Mar;218(3):444-452. doi: 10.2214/AJR.21.26775. Epub 2021 Oct 13.
Cardiac CTA is required for preprocedural workup before transcatheter aortic valve replacement (TAVR) and can be used to assess functional parameters of the left atrium (LA). We aimed to evaluate the utility of functional and volumetric LA parameters derived from cardiac CTA to predict mortality in patients with severe aortic stenosis (AS) undergoing TAVR. This retrospective study included 175 patients with severe AS (92 men, 83 women; median age, 79.0 years) who underwent cardiac CTA for clinical pre-TAVR assessment. A postdoctoral research fellow calculated maximum and minimum LA volumes using biplane area-length measurements; these values were indexed to body surface area, and maximum and minimum LA volume index (LAVI and LAVI, respectively) values were calculated. The LA emptying fraction (LAEF) was automatically calculated. All-cause mortality within a 24-month follow-up period after TAVR was recorded. To identify parameters predictive of mortality, Cox regression analysis was performed, and results were summarized by hazard ratio (HR) and 95% CI. The Harrell C-index was used to assess model performance. A radiology resident repeated the measurements in a random sample of 20% ( = 35) of the cases, and interobserver agreement was computed using the intraclass correlation coefficient (ICC). Thirty-eight deaths (21.7%) were recorded within a median follow-up of 21 months. LAVI (HR, 1.02 [95% CI, 1.01-1.04]; = .01), LAVI (HR, 1.02 [95% CI, 1.01-1.04]; < .001), and LAEF (HR, 0.97 [95% CI, 0.95-0.99]; = .002) were predictive of mortality in univariable analysis. After adjusting for clinical parameters, only LAEF (HR, 0.97 [95% CI, 0.94-0.99]; = .02) independently predicted mortality. The C-index of the Society of Thoracic Surgeons Predicted Risk of Mortality (STS-PROM) significantly increased from 0.636 to 0.683, 0.694, and 0.700 when incorporating into the model LAVI, LAVI, and LAEF, respectively. The ICC for maximum and minimum LA volumes and LAEF ranged from 0.94 to 0.99. LAEF derived from preprocedural cardiac CTA independently predicts mortality in patients with severe AS undergoing TAVR. Cardiac CTA-derived LA function, evaluated during pre-TAVR workup, can be used to assess preprocedural risk and may improve risk stratification in post-TAVR surveillance.
在经导管主动脉瓣置换术（TAVR）前的术前检查中需要进行心脏 CT 血管造影（cardiac CTA），并可用于评估左心房（LA）的功能参数。我们旨在评估从心脏 CTA 得出的左心房功能和容积参数在预测接受 TAVR 的严重主动脉瓣狭窄（AS）患者死亡率方面的作用。这项回顾性研究纳入了 175 名接受 TAVR 临床前评估的严重 AS 患者（92 名男性，83 名女性；中位年龄为 79.0 岁）。一名博士后研究员使用双平面面积长度测量法计算最大和最小左心房容积；这些值与体表面积成比例，计算出最大和最小左心房容积指数（LAVI 和 LAVI）值。左心房排空分数（LAEF）自动计算。记录 TAVR 后 24 个月内的全因死亡率。为了确定预测死亡率的参数，进行了 Cox 回归分析，并通过危险比（HR）和 95%置信区间（CI）进行总结。使用 Harrell C 指数评估模型性能。一名放射科住院医师在 20%（n=35）的随机样本中重复测量，使用组内相关系数（ICC）计算观察者间一致性。在中位随访 21 个月时记录了 38 例死亡（21.7%）。LAVI（HR，1.02[95%CI，1.01-1.04]；=0.01）、LAVI（HR，1.02[95%CI，1.01-1.04]；<0.001）和 LAEF（HR，0.97[95%CI，0.95-0.99]；=0.002）在单变量分析中预测死亡率。在校正临床参数后，只有 LAEF（HR，0.97[95%CI，0.94-0.99]；=0.02）独立预测死亡率。纳入模型的 LAVI、LAVI 和 LAEF 后，胸外科医生协会预测死亡率风险（STS-PROM）的 C 指数分别从 0.636 增加到 0.683、0.694 和 0.700。最大和最小左心房容积和 LAEF 的 ICC 值范围为 0.94 至 0.99。从 TAVR 术前心脏 CTA 得出的 LAEF 可独立预测严重 AS 患者的死亡率。在 TAVR 术前检查期间评估的心脏 CTA 衍生的 LA 功能可用于评估术前风险，并可能改善 TAVR 后监测中的风险分层。
