Cardiovascular Division, Department of Medicine University of Minnesota Medical School Minneapolis MN.
Department of Medicine University of Minnesota Medical School Minneapolis MN.
J Am Heart Assoc. 2023 Aug 15;12(16):e029973. doi: 10.1161/JAHA.123.029973. Epub 2023 Aug 10.
Background A total of 40% of patients with severe aortic stenosis (AS) have low-gradient AS, raising uncertainty about AS severity. Aortic valve calcification, measured by computed tomography (CT), is guideline-endorsed to aid in such cases. The performance of different CT-derived aortic valve areas (AVAs) is less well studied. Methods and Results Consecutive adult patients with presumed moderate and severe AS based on echocardiography (AVA measured by continuity equation on echocardiography <1.5 cm) who underwent cardiac CT were identified retrospectively. AVAs, measured by direct planimetry on CT (AVA) and by a hybrid approach (AVA measured in a hybrid manner with echocardiography and CT [AVA]), were measured. Sex-specific aortic valve calcification thresholds (≥1200 Agatston units in women and ≥2000 Agatston units in men) were applied to adjudicate severe or nonsevere AS. A total of 215 patients (38.0% women; mean±SD age, 78±8 years) were included: normal flow, 59.5%; and low flow, 40.5%. Among the different thresholds for AVA and AVA, diagnostic performance was the best for AVA <1.2 cm (sensitivity, 85%; specificity, 26%; and accuracy, 72%), with no significant difference by flow status. The percentage of patients with correctly classified AS severity (correctly classified severe AS+correctly classified moderate AS) was as follows; AVA measured by continuity equation on echocardiography <1.0 cm, 77%; AVA <1.2 cm, 73%; AVA <1.0 cm, 58%; AVA <1.2 cm, 59%; and AVA <1.0 cm, 45%. AVA cut points of 1.52 cm for normal flow and 1.56 cm for low flow, provided 95% specificity for excluding severe AS. Conclusions CT-derived AVAs have poor discrimination for AS severity. Using an AVA <1.2-cm threshold to define severe AS can produce significant error. Larger AVA thresholds improve specificity.
背景 共有 40%的严重主动脉瓣狭窄（AS）患者存在低梯度 AS，这增加了对 AS 严重程度判断的不确定性。通过计算机断层扫描（CT）测量的主动脉瓣钙化是指导此类病例的标准。不同 CT 衍生的主动脉瓣口面积（AVA）的性能研究较少。 方法和结果 回顾性地确定了连续的成人患者，这些患者根据超声心动图（AVA 通过超声心动图的连续方程测量<1.5cm）被认为是中度和重度 AS，并进行了心脏 CT。通过 CT 直接测量的 AVA（AVA）和混合方法（通过超声心动图和 CT 混合测量的 AVA [AVA]）测量 AVA。应用性别特异性主动脉瓣钙化阈值（女性≥1200 个 Agatston 单位，男性≥2000 个 Agatston 单位）判断严重或非严重 AS。共纳入 215 例患者（38.0%为女性；平均年龄 78±8 岁）：正常血流 59.5%；低血流 40.5%。在不同的 AVA 和 AVA 阈值中，AVA<1.2cm 的诊断性能最佳（敏感性为 85%，特异性为 26%，准确性为 72%），且不受血流状态的影响。正确分类 AS 严重程度的患者百分比（正确分类严重 AS+正确分类中度 AS）如下；超声心动图连续方程测量的 AVA<1.0cm，77%；AVA<1.2cm，73%；AVA<1.0cm，58%；AVA<1.2cm，59%；AVA<1.0cm，45%。对于正常血流，AVA 截断值为 1.52cm，对于低血流，AVA 截断值为 1.56cm，特异性为 95%，可排除严重 AS。 结论 CT 衍生的 AVAs 对 AS 严重程度的区分能力较差。使用 AVA<1.2cm 阈值来定义严重 AS 可能会产生重大错误。较大的 AVA 阈值可提高特异性。
