Background

Aortic valve calcification (AVC) quantification is computed from multidetector computed tomography (MDCT). The aim of this study was to test the hypothesis that three-dimensional (3D) transthoracic echocardiography can be used to provide a bedside method to assess AVC.

Methods

The study included 94 patients (mean age, 78 ± 12 years; mean aortic valve [AV] area, 1.0 ± 0.6 cm²) referred for MDCT and echocardiography for AV assessment. Apical 3D full-volume data sets focused on the AV region were acquired during transthoracic echocardiography, and a region-growing algorithm was applied offline to compute 3D transthoracic echocardiographic AVC (AVC-3DEcho). AVC-3DEcho was compared with AVC by MDCT and with calcium weight in the subgroup of patients referred for surgery, with explanted AVs analyzed by a pathologist (n = 22).

Results

In the explanted valve group, AVC-3DEcho score exhibited fair correlations with MDCT score (r = 0.85, P < .001), calcium load (r = 0.81, P < .001), and peak AV velocity (r = 0.64, P < .001). In the overall population, AVC-3DEcho score correlated modestly with MDCT score (r = 0.61, P < .001) but had similar accuracy to identify severe aortic stenosis (area under the curve = 0.94). AVC-3DEcho > 1,054 mm³ identified severe aortic stenosis with specificity of 100% and sensitivity of 76%. In addition, AVC-3DEcho was associated with the presence of significant paravalvular regurgitation after transcatheter aortic valve implantation. Finally, intraobserver and interobserver variability for AVC-3DEcho score was 4.2% and 8.9%, respectively.

Conclusions

AVC-3DEcho correlated with calcium weight obtained from pathologic analysis and MDCT. These data suggest that a bedside method for quantifying AV calcification with ultrasound is feasible.

中文翻译：

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三维超声心动图定量主动脉瓣钙化的新方法

背景

主动脉瓣钙化（AVC）量化是从多探测器计算机断层扫描（MDCT）计算得出的。本研究的目的是检验以下假设：三维（3D）经胸超声心动图可用于提供床旁评估AVC的方法。

方法

该研究包括94名患者（平均年龄78±12岁；平均主动脉瓣[AV]面积1.0±0.6 cm ²）接受MDCT和超声心动图检查，以进行AV评估。经胸超声心动图期间获取集中在AV区域的顶端3D全量数据集，并离线应用区域增长算法来计算3D经胸超声心动图AVC（AVC-3DEcho）。通过MDCT将AVC-3DEcho与AVC进行了比较，并对接受手术治疗的患者亚组中的钙重量进行了比较，并由病理学家对外植性AV进行了分析（n  = 22）。

结果

在外植瓣膜组中，AVC-3DEcho评分与MDCT评分（r  = 0.85，P  <.001），钙负荷（r  = 0.81，P  <.001）和AV峰值速度（r  = 0.64，P）表现出明显的相关性。  <.001）。在总体人群中，AVC-3DEcho评分与MDCT评分的相关性中等（r  = 0.61，P  <.001），但是在识别严重的主动脉狭窄方面具有相似的准确性（曲线下面积= 0.94）。AVC-3DEcho> 1,054毫米³鉴定出严重的主动脉瓣狭窄，特异性为100％，敏感性为76％。此外，经导管主动脉瓣植入后，AVC-3DEcho与明显的瓣周关闭不全有关。最后，AVC-3DEcho评分的观察者内和观察者间变异性分别为4.2％和8.9％。

结论

AVC-3DEcho与通过病理分析和MDCT获得的钙重量相关。这些数据表明，用超声定量房颤钙化的床旁方法是可行的。