ABSTRACT
Spontaneous coronary artery dissection (SCAD) is a nonatherosclerotic cause of myocardial infarction in young and middle-aged women that has gained increasing awareness in recent years. Its diagnosis presents a challenge. Invasive coronary angiography is the primary imaging modality for diagnosing SCAD; however, it carries risk in these patients, who have an increased predisposition to complications. Advances in CT technology enable robust noninvasive evaluation of the coronary arteries at low radiation doses and have been increasingly utilized for the diagnosis or resolution of SCAD, in hemodynamically stable patients or when diagnosis of SCAD is uncertain at invasive angiography, particularly in proximal vessels. However, criteria for the diagnosis of SCAD with use of coronary CT angiography (CCTA) have not been currently established, and sensitivity and specificity for diagnosis have not yet been defined. The appearance of SCAD at CCTA can be subtle and can be missed, especially in distal small-caliber coronary arteries; hence utilization of other noninvasive imaging multimodalities may help solve this diagnostic challenge. Accurate and prompt diagnosis is vital, as management of SCAD differs significantly from that of traditional atherosclerotic acute coronary syndromes, with conservative management preferred for the majority of SCAD patients, and invasive treatment reserved for those with ongoing or recurrent ischemia, heart failure, or hemodynamic compromise. The goal of this review is twofold: (a) to discuss the potential role of CCTA in the diagnosis of SCAD, and (b) to discuss the role of multimodality imaging that may improve diagnostic yield, guide management, and enable subsequent surveillance. An invited commentary by Ordovas is available online. Online supplemental material is available for this article. ©RSNA, 2021.
Subject(s)
Coronary Vessel Anomalies , Vascular Diseases , Coronary Angiography , Coronary Vessel Anomalies/diagnostic imaging , Dissection , Female , Humans , Middle Aged , Risk Factors , Vascular Diseases/diagnostic imagingABSTRACT
BACKGROUND: The presence of calcified plaque in coronary arteries can be quantified by using 0.5-mm isotropic reconstructions from 320-row CT without increased radiation dose. Little is known about reclassification of patients with non-zero Agatston scores and quantitative measures of calcified plaque using 0.5-mm reconstructions. OBJECTIVE: The aim was to compare proportions of zero vs. non-zero Agatston scores (subclinical atherosclerosis) in 0.5-mm isotropic reconstructions vs. standard 3.0-mm and CT angiography (CTA) scans on 320-row CT. METHODS: Prospectively, we quantified calcified plaque in coronary arteries in 104 patients by using non-contrast-enhanced scans with 0.5 and 3.0 mm. Coronary calcium assessment was determined by 2 observers. Clinically indicated CTA was also performed; coronary calcium assessment findings were compared with CTA. Ranked Wilcoxon test and χ2 test were performed for comparison. Reproducibility for proportion of zero vs non-zero was assessed by κ statistics. RESULTS: Median Agatston score (41.9 [interquartile range (IQR), 3.7-213.6] vs. 5.2 [IQR, 0.0-128.5]), calcium volume (53.6 mm3 [IQR, 8.1-202.3] vs. 5.1 mm(3) [IQR, 0.0-96.8],), and lesion number (10.0 [IQR, 3.5-18.5] vs. 1.0 [IQR, 0.0-6.0]) were significantly higher on 0.5-mm reconstruction (P < .0001) than on 3.0-mm reconstruction. More patients with subclinical atherosclerosis were detected on 0.5 mm than on 3.0 mm and CTA scans (76.9% vs. 53.8% vs. 54.8%; P < .0001). The κ values for inter-rater agreement were 0.94 and 0.52 on 3.0- and 0.5-mm data sets, respectively. However, when Agatston scores < 10 were excluded from analysis, the κ value rose to 0.83. CONCLUSION: Isotropic 0.5-mm reconstruction detected 23.1% and 22.1% more patients with subclinical atherosclerosis than standard 3.0-mm scans and CTA, which may be more sensitive for the detection of subclinical atherosclerosis; its potential clinical utility needs to be validated in large, prospective studies.
