Objectives

To determine whether calcifications of the coronary arteries (coronary artery calcium 0 to 4 score), or extending the assessment also to cardiac valves and thoracic aorta (overall calcium 0 to 8 score), as seen on computed tomography for attenuation correction during stress-scintigraphy (SPECT-CT), are associated with total mortality and non-fatal myocardial infarction. We aimed to assess whether these calcifications added to the prognostic value of SPECT imaging.

Background

The presence/amount of calcium in the coronary arteries, but also in the heart valves and aorta, has been associated with cardiovascular (CV) and all-cause mortality. This information can be obtained during SPECT-CT examinations, where low resolution CT images are co-registered for attenuation correction of myocardial perfusion, but then discarded.

Methods

Clinical data were collected on 353 consecutive patients submitted to stress SPECT-CT between Sept 2010 and Oct 2012, for suspected coronary artery disease (CAD). Follow-up data on outcomes were collected retrospectively.

Results

Mean age was 72 and 58% were male. Mean follow-up was 6.4 years, during which 48 subjects died (15 from CV causes) and 10 had non-fatal myocardial infarction (MI). Reversible perfusion defects were detected in 55 patients (15.6%), 39 of whom (11%) had >mild defects. The presence of a calcium score > 1 in the attenuation correction images was the strongest univariate predictor of all-cause death or MI (hazard ratio 7.21, p < .001). On multivariate analysis, controlling for age, gender and myocardial perfusion defects an overall calcium score > 2 remained a predictor of all-cause death or non-fatal MI (hazard ratio 4.12, p < .001).

Conclusions

Visual assessment of coronary or overall coronary, cardiac and aortic calcium in the CT images used for attenuation correction during SPECT-CT is feasible and reproducible. It was strongly associated with all-cause death and MI, even after controlling for clinical variables and myocardial perfusion data. This simple visual calcium assessment does not add additional costs or radiation, and may significantly improve risk-assessment of patients with suspected CAD undergoing SPECT-CT.

Condensed abstract

Calcium in the coronary arteries, heart valves and aorta has been associated with worse prognosis. We sought to determine whether assessment of such calcifications on computed tomography images (co-registered for myocardial perfusion attenuation correction and then discarded) are independently associated with long-term outcome on top of available data.

We enrolled 353 consecutive patients, referred for suspected coronary artery disease. An overall calcium score > 1 in the attenuation correction images was the strongest univariate (hazard ratio 7.21, p < .001) and multivariate predictor of all-cause death or non-fatal MI (hazard ratio 4.12, p < .001), even after controlling for clinical variables and myocardial perfusion data.

中文翻译：

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视觉评估冠状动脉和心脏钙在闪烁显像术期间的灌注数据优于预测不良结果的灌注数据。

目标

确定是否在计算机断层扫描上观察到冠状动脉钙化（冠状动脉钙化0到4分），还是将评估扩展到心脏瓣膜和胸主动脉（总钙0到8分），以进行应力闪烁成像的衰减校正（SPECT-CT）与总死亡率和非致命性心肌梗死有关。我们旨在评估这些钙化是否增加了SPECT成像的预后价值。

背景

冠状动脉以及心脏瓣膜和主动脉中钙的存在/含量与心血管疾病（CV）和全因死亡率相关。此信息可以在SPECT-CT检查期间获得，在该检查中，低分辨率CT图像被共同配准用于心肌灌注的衰减校正，但随后被丢弃。

方法

收集了2010年9月至2012年10月之间因压力性SPECT-CT而被怀疑患有冠状动脉疾病（CAD）的353例患者的临床数据。回顾性收集有关结果的随访数据。

结果

平均年龄为72岁，男性占58％。平均随访时间为6.4年，在此期间有48名患者死亡（15名由于CV原因），其中10名患有非致命性心肌梗塞（MI）。在55例患者（15.6％）中检测到可逆的灌注缺陷，其中39例（11％）具有轻度缺陷。衰减校正图像中的钙得分> 1是全因死亡或心肌梗死的最强单变量预测因子（危险比7.21，p  <.001）。在多变量分析中，控制年龄，性别和心肌灌注缺陷，总钙得分> 2仍是全因死亡或非致命性MI的预测指标（危险比4.12，p  <0.001）。

结论

在SPECT-CT期间用于衰减校正的CT图像中，对冠状​​动脉或总体冠状动脉，心脏和主动脉钙的视觉评估是可行且可重现的。即使控制了临床变量和心肌灌注数据，它也与全因死亡和心肌梗死密切相关。这种简单的视觉钙评估不会增加额外的成本或放射线，并且可以显着提高对疑似CAD患者进行SPECT-CT的风险评估。

浓缩摘要

冠状动脉，心脏瓣膜和主动脉中的钙与不良预后相关。我们试图确定在计算机断层扫描图像（共同注册用于心肌灌注衰减校正，然后丢弃）上对此类钙化的评估是否与可获得的数据之上的长期结果独立相关。

我们招募了353名连续的患者，因怀疑冠心病而转诊。衰减校正图像中的总钙得分> 1是最强的单变量（危险比7.21，p  <.001），也是全因死亡或非致命性MI的多变量预测因子（危险比4.12，p <.001），甚至在控制临床变量和心肌灌注数据后。