Department of Imaging Science, University of Rochester Medical Center, Rochester, NY.
J Thorac Imaging. 2020 Sep;35(5):309-316. doi: 10.1097/RTI.0000000000000433.
Identify a measurable parameter from test bolus of computed tomography angiography that can differentiate aortic stenosis patients with normal systolic function from those with heart failure and reduced ejection fraction (HFrEF).
This retrospective study included patients (undergoing evaluation for transcatheter aortic valve replacement) who had retrospective electrocardiogram-gated cardiac computed tomography angiography using test bolus. The measured variables were time to peak contrast enhancement in the pulmonary artery (PAtime), in the ascending (AsAotime) and descending aorta (DsAotime). From these, the pulmonary transit time (PTT: difference between time to peak enhancement in the ascending aorta to peak enhancement in the main pulmonary artery), aortic transit time (ATT: difference between time to peak enhancement in the descending aorta to time to peak enhancement in the ascending aorta) and DsAotime-PAtime were also calculated. Biventricular volumes and function were calculated.The subjects were classified on the basis of ventricular ejection fractions: normal (EF>50%), midrange (EF 40% to 50%), and HF patients with reduced EF (EF<40%). Continuous variables were compared between all groups using ordinary 1-way analysis of variance, while sex was compared using the Fisher exact test. The unpaired t tests were used to compare between the normal and HF groups. Receiver operating characteristic analysis was used in predicting decreased cardiac function (EF<40% vs. EF>50%).
AsAotime and PTT were significant predictors of low biventricular EF when controlling for sex and body mass index (AsAotime: odds ratio=0.74 [95% confidence interval=0.61-0.91], P=0.005; PTT: odds ratio=0.64 95% confidence interval=0.46-0.88], P=0.006). A threshold of 23 seconds for AsAotime resulted in 72.1% sensitivity and 71.4% specificity, and 79.1% sensitivity and 64.3% specificity for DsAotime.
The time to peak contrast enhancement from the test bolus images correlates with cardiac function. Decreased biventricular systolic dysfunction can be predicted if the time to peak contrast enhancement is >23 seconds in the ascending or descending aorta.
确定 CT 血管造影测试团注中可区分射血分数正常的主动脉瓣狭窄患者与心力衰竭和射血分数降低（HFrEF）患者的可测量参数。
本回顾性研究纳入了（接受经导管主动脉瓣置换术评估）进行回顾性心电图门控心脏 CT 血管造影的患者，使用测试团注。测量的变量包括肺动脉峰值增强时间（PAtime）、升主动脉（AsAotime）和降主动脉（DsAotime）的峰值增强时间。由此还计算了肺动脉传输时间（PTT：升主动脉峰值增强时间与主肺动脉峰值增强时间之间的差异）、主动脉传输时间（ATT：降主动脉峰值增强时间与升主动脉峰值增强时间之间的差异）和 DsAotime-PAtime。还计算了双心室容积和功能。根据心室射血分数将受试者分为正常（EF>50%）、中值（EF 40%至 50%）和射血分数降低的心力衰竭患者（EF<40%）。使用普通单因素方差分析比较所有组之间的连续变量，而性别使用 Fisher 确切检验进行比较。使用配对 t 检验比较正常组和 HF 组之间的差异。使用接受者操作特征分析预测心功能降低（EF<40%与 EF>50%）。
控制性别和体重指数后，AsAotime 和 PTT 是低双心室 EF 的显著预测因子（AsAotime：优势比=0.74 [95%置信区间=0.61-0.91]，P=0.005；PTT：优势比=0.64 [95%置信区间=0.46-0.88]，P=0.006）。AsAotime 的阈值为 23 秒时，敏感性为 72.1%，特异性为 71.4%，DsAotime 的敏感性为 79.1%，特异性为 64.3%。
测试团注图像的峰值对比增强时间与心功能相关。如果升主动脉或降主动脉的峰值对比增强时间>23 秒，则可预测双心室收缩功能障碍降低。
