Messika-Zeitoun David, Aubry Marie-Christine, Detaint Delphine, Bielak Lawrence F, Peyser Patricia A, Sheedy Patrick F, Turner Stephen T, Breen Jerome F, Scott Christopher, Tajik A Jamil, Enriquez-Sarano Maurice
Division of Cardiovascular Diseases and Internal Medicine, Mayo Clinic and Mayo Foundation, Rochester, Minn 55905, USA.
Circulation. 2004 Jul 20;110(3):356-62. doi: 10.1161/01.CIR.0000135469.82545.D0. Epub 2004 Jul 12.
Electron-beam computed tomography (EBCT) is used to measure coronary calcification but not for aortic valve calcification (AVC). Its accuracy, association with aortic stenosis (AS) severity, and diagnostic and prognostic value with respect to AVC are unknown.
In 30 explanted aortic valves, the AVC score by EBCT (1125+/-1294 Agatston units [AU]) showed a strong linear correlation (r=0.96, P<0.0001) with valvular calcium weight (653+/-748 mg) by pathology that allowed estimation of calcium weight as AVC score/1.7, with a small standard error of the estimate (53 mg). In 100 consecutive clinical patients, we measured AVC by EBCT and AS severity by echocardiographic aortic valve area (AVA). The AVC score was 1316+/-1749 AU (range 0 to 7226 AU). Intraobserver and interobserver variabilities were excellent (4+/-4% and 4+/-10%, respectively). AVC and AVA were strongly associated (r=0.79, P<0.0001) but had a curvilinear relationship that suggested that AVC and AVA provide complementary information. AVC score > or =1100 AU provided 93% sensitivity and 82% specificity for diagnosis of severe AS (AVA <1 cm2), with a receiver operator characteristic curve area of 0.89. AVC assessment by echocardiography was often more severe than by EBCT (P<0.0001). During follow-up, 22 patients either died, developed heart failure, or required surgery. With adjustment for age, sex, symptoms, ejection fraction, and AVA, the AVC score was independently predictive of event-free survival (risk ratio 1.06 per 100-AU increment [1.02 to 1.10], P<0.001), even after adjustment for echocardiographic calcifications.
AVC is accurately and reproducibly measured by EBCT and shows a strong association and diagnostic value for severe AS. The curvilinear relationship between AVC and AVA suggests these measures are complementary, and indeed, AVC provides independent outcome information. Thus, AVC is an important measurement in the evaluation of patients with AS.
电子束计算机断层扫描（EBCT）用于测量冠状动脉钙化，但不用于主动脉瓣钙化（AVC）。其准确性、与主动脉瓣狭窄（AS）严重程度的相关性以及对AVC的诊断和预后价值尚不清楚。
在30个离体主动脉瓣中，EBCT测得的AVC评分（1125±1294阿加斯顿单位[AU]）与病理学测得的瓣膜钙重量（653±748毫克）呈强线性相关（r = 0.96，P<0.0001），据此可将钙重量估算为AVC评分/1.7，估算的标准误差较小（53毫克）。在100例连续临床患者中，我们通过EBCT测量AVC，并通过超声心动图测量主动脉瓣面积（AVA）评估AS严重程度。AVC评分为1316±1749 AU（范围0至7226 AU）。观察者内和观察者间的变异性都很好（分别为4±4%和4±10%）。AVC与AVA密切相关（r = 0.79，P<0.0001），但呈曲线关系，提示AVC和AVA提供互补信息。AVC评分≥1100 AU对重度AS（AVA<1平方厘米）诊断的敏感性为93%，特异性为82%，受试者工作特征曲线面积为0.89。超声心动图评估的AVC通常比EBCT评估的更严重（P<0.0001）。随访期间，22例患者死亡、发生心力衰竭或需要手术。在调整年龄、性别、症状、射血分数和AVA后，AVC评分可独立预测无事件生存率（每增加100 AU的风险比为1.06[1.02至1.10]，P<0.001），即使在调整超声心动图钙化后也是如此。
EBCT能准确且可重复地测量AVC，对重度AS显示出强相关性和诊断价值。AVC与AVA之间的曲线关系提示这些测量方法具有互补性，实际上，AVC提供独立的预后信息。因此，AVC是评估AS患者的一项重要测量指标。
