Hwang Ji-Won, Kim Sung Mok, Park Sung-Ji, Cho Eun Jeong, Lee Sans-Chol, Choe Yeon Hyeon, Park Seung Woo
From the Department of Medicine, Division of Cardiology (J-WH, S-JP, S-CL, SWP); Department of Radiology (SMK, YHC); Cardiovascular Imaging Center, Heart Vascular Stroke Institute, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul (SMK, SJP, S-CL, YHC, SWP); and Division of Cardiology, Department of Medicine, National Cancer Center, Goyang, Korea (EJC).
Medicine (Baltimore). 2016 Mar;95(9):e2906. doi: 10.1097/MD.0000000000002906.
Invasive coronary angiography (ICA) is the recommended assessment for coronary artery disease in patients undergoing elective aortic valve replacement (AVR). Noncontrast computed tomography (CT) is useful for evaluating lung lesions and calcifications at the cannulation site of the ascending aorta. The purpose of this study was to evaluate the role of noncontrast CT in the visual assessment of coronary artery calcification (CAC) in patients undergoing AVR. We retrospectively identified patients with significant aortic stenosis (AS) who were referred for AVR between January 2006 and December 2013. Among these, we included 386 patients (53.6% males, 69.2 ± 8.4 years) who underwent both noncontrast CT and ICA. Significant coronary artery stenosis (CAS) in the ICA was defined as luminal stenosis ≥70%. The 4 main coronary arteries were visually assessed on noncontrast CT and were scored based on the Weston score as follows: 0, no visually detected calcium; 1, a single high-density pixel detected; 3, calcium was dense enough to create a blooming artifact; and 2, calcium in between 1 and 3. Four groups were reclassified by the sum of the Weston scores from each vessel, as follows: noncalcification (0); mild calcification (1-4); moderate calcification (5-8); and severe calcification (9-12). Receiver-operating characteristic (ROC) analysis was generated to identify the cutoff Weston score values for predicting significant CAS. Diagnostic estimates were calculated based on these cutoffs. In the ICA analysis, 62 of the 386 patients (16.1%) had significant CAS. All patients were divided into 4 groups. The noncalcification group had 97 subjects (Weston score 0), the mild degree group had 100 (2.6 ± 1.0), the moderate calcification group had 114 (6.6 ± 1.1), and the severe calcification group had 75 (10.7 ± 1.1). The prevalence of significant CAS in the noncalcification, mild, moderate, and severe groups was 1% (1/97), 5% (5/100), 24% (27/114), and 39% (29/75), respectively. The group with CAS had significantly more CAC than the group without CAS (8.37 ± 2.93 vs 4.01 ± 3.75, P < 0.001). The cutoff value (by Weston score) for predicting significant CAS is ≥5 (sensitivity 90.3%, specificity 59.0%, positive predictive value 29.6%, and negative predictive value 97%). The degree of CAC detected on noncontrast CT can help to predict significant CAS in AS patients who are referred for AVR. For the clinicians, the visual assessment of CAC on noncontrast CT was easy and useful for estimating CAS. Therefore, ICA should be recommended to selective patients based on patients' CAC and Weston scores during the preoperative evaluation for elective AVR.
对于接受择期主动脉瓣置换术（AVR）的患者，侵入性冠状动脉造影（ICA）是推荐用于评估冠状动脉疾病的方法。非增强计算机断层扫描（CT）有助于评估升主动脉插管部位的肺部病变和钙化情况。本研究的目的是评估非增强CT在接受AVR患者的冠状动脉钙化（CAC）视觉评估中的作用。我们回顾性地确定了2006年1月至2013年12月期间因严重主动脉瓣狭窄（AS）而被转诊接受AVR的患者。其中，我们纳入了386例患者（男性占53.6%，年龄69.2±8.4岁），这些患者均接受了非增强CT和ICA检查。ICA中显著冠状动脉狭窄（CAS）定义为管腔狭窄≥70%。在非增强CT上对4条主要冠状动脉进行视觉评估，并根据韦斯顿评分进行评分如下：0分，未视觉检测到钙化；1分，检测到单个高密度像素；3分，钙化密度足以产生光晕伪影；2分，介于1分和3分之间。根据每条血管的韦斯顿评分总和将患者重新分为四组，如下：无钙化（0分）；轻度钙化（1 - 4分）；中度钙化（5 - 8分）；重度钙化（9 - 12分）。生成受试者操作特征（ROC）分析以确定预测显著CAS的临界韦斯顿评分值。基于这些临界值计算诊断估计值。在ICA分析中，386例患者中有62例（16.1%）存在显著CAS。所有患者分为四组。无钙化组有97名受试者（韦斯顿评分为0分），轻度组有100名（2.6±1.0分），中度钙化组有114名（6.6±1.1分），重度钙化组有75名（10.7±1.1分）。无钙化、轻度、中度和重度组中显著CAS的患病率分别为1%（1/97）、5%（5/100）、24%（27/114）和39%（29/75）。有CAS组的CAC明显多于无CAS组（8.37±2.93 vs 4.01±3.75，P<0.001）。预测显著CAS的临界值（按韦斯顿评分）为≥5分（敏感性90.3%，特异性59.0%，阳性预测值29.6%，阴性预测值97%）。在非增强CT上检测到的CAC程度有助于预测被转诊接受AVR的AS患者的显著CAS。对于临床医生而言，在非增强CT上对CAC进行视觉评估对于估计CAS既简单又有用。因此，在择期AVR的术前评估中，应根据患者的CAC和韦斯顿评分向选择性患者推荐ICA。
