Department of Emergency Medicine, Hospital of the University of Pennsylvania, Philadelphia, USA.
Acad Emerg Med. 2011 Oct;18(10):1065-71. doi: 10.1111/j.1553-2712.2011.01173.x.
Coronary angiography calcium score (CACS) is included for patients who receive coronary computed tomography angiography (CTA) as part of diagnostic testing for low-risk chest pain. Both tests add radiation exposure, and it is unclear whether the combination provides more information than either test alone. The objective was to asses if CACS = 0 determines freedom from coronary artery disease (CAD) and whether the addition of CACS to coronary CT angiography provides additional risk stratification information or helps predict 30-day cardiovascular outcomes.
This was a secondary analysis of a prospective cohort study at an urban university hospital emergency department (ED), of patients with symptoms suggestive of potential acute coronary syndrome (ACS) and low Thrombolysis in Myocardial Infarction (TIMI) risk scores who received coronary CTA. Data collected included demographics and medical history. The main outcome was CAD, defined as the presence of a maximal stenosis >50% on coronary CTA, stratified by CACS results. The secondary outcome was cardiovascular events including death, myocardial infarction, or revascularization at 30 days. Data were analyzed with standard descriptive techniques and relative risks (RR) with 95% confidence intervals (CIs).
A total of 1,049 patients were enrolled (median age = 48.1 years; interquartile range [IQR] = 42.4 to 53.3 years); 55% were female, and 63% were black or African American. Of these, 17 of 795 (2.1%) with CACS of 0 had CAD, 16 of 169 patients (9.5%) with CACS of 0.1 to 99 had CAD, 53.3% (32 of 60) with CACS between 100 and 399 had CAD, and 10 of 23 (43.5%) with CACS ≥ 400 had CAD. There was a higher likelihood of significant CAD with increased CACS. Patients who had a calcium score of 0 but still had CAD were more likely to be young (50 years old or less; RR = 1.73, 95% CI = 1.01 to 2.96). For the secondary outcome, there were 15 cardiovascular events within 30 days: one patient with CACS = 0 and no CAD (1 of 733; 0.1%), one patient with CACS > 0 and no CAD (1 of 182; 0.5%), four patients with CACS = 0 and CAD (4 of 17; 23.5%), and nine patients with CACS > 0 and CAD (9 of 58; 15.5%), with a net reclassification index of -0.001 (p = 0.32).
In the study sample, elevated CACS was associated with a higher likelihood of underlying CAD on coronary CTA, but the addition of CACS to coronary CTA did not help predict 30-day cardiovascular events.
冠状动脉 CT 血管造影（CTA）中的冠状动脉钙评分（CACS）适用于接受低危胸痛诊断性检查的患者。这两种检查都增加了辐射暴露，尚不清楚联合使用是否比单独使用任何一种检查提供更多信息。本研究旨在评估 CACS=0 是否能排除冠状动脉疾病（CAD），以及 CACS 联合冠状动脉 CTA 是否能提供更多的风险分层信息或有助于预测 30 天心血管结局。
这是一项对城市大学医院急诊科疑似潜在急性冠脉综合征（ACS）且血栓形成溶栓治疗（TIMI）风险评分低的患者进行前瞻性队列研究的二次分析，这些患者接受了冠状动脉 CTA。收集的数据包括人口统计学和病史。主要结局是 CAD，定义为冠状动脉 CTA 上最大狭窄程度＞50%，根据 CACS 结果进行分层。次要结局是 30 天内的心血管事件，包括死亡、心肌梗死或血运重建。采用标准描述性技术和相对风险（RR）及其 95%置信区间（CI）进行数据分析。
共纳入 1049 例患者（中位年龄 48.1 岁；四分位间距[IQR]为 42.4 至 53.3 岁）；55%为女性，63%为黑种人或非裔美国人。其中，795 例 CACS 为 0 的患者中有 17 例（2.1%）存在 CAD，169 例 CACS 为 0.1 至 99 的患者中有 16 例（9.5%）存在 CAD，CACS 为 100 至 399 的患者中有 53.3%（32 例）存在 CAD，CACS≥400 的患者中有 10 例（43.5%）存在 CAD。CACS 升高与 CAD 的可能性增大相关。CACS 为 0 但仍存在 CAD 的患者更可能年轻（50 岁或以下；RR=1.73，95%CI=1.01 至 2.96）。对于次要结局，30 天内发生了 15 例心血管事件：1 例 CACS=0 且无 CAD（733 例中的 1 例；0.1%），1 例 CACS＞0 且无 CAD（182 例中的 1 例；0.5%），4 例 CACS=0 且有 CAD（17 例中的 4 例；23.5%），9 例 CACS＞0 且有 CAD（58 例中的 9 例；15.5%），净重新分类指数为-0.001（p=0.32）。
在研究样本中，升高的 CACS 与冠状动脉 CTA 上潜在 CAD 的可能性增大相关，但 CACS 联合冠状动脉 CTA 并不能帮助预测 30 天心血管事件。
