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We intended to investigate the pattern of myocardial perfusion defects (PDs) in cases of acute coronary syndrome visualized by non-gated high-pitch Contrast-enhanced computed tomography angiography (CTA) in patients admitted to emergency department (ED) for suspected aortic dissection.
From April 2013 to October 2016, 899 patients underwent high-pitch aortic CTA for suspected aortic dissection at ER. Thirty-eight patients who were finally diagnosed as acute coronary syndrome (ACS) and received subsequent coronary catheterization within one month were recruited. The study subjects were grouped into ST-elevation myocardial infarct (STEMI) in 9, Non-ST-elevation myocardial infarct (NSTEMI) in 18, and unstable angina (UA) in 11, based on the clinical diagnosis.
Visual patterns of PDs were classified to transmural, non-transmural, and subendocardial.
Quantitative categorizations of PD based on thickness were grouped to more or less than 50% involvement. The infarct/ischemia related artery (IRA) was confirmed via coronary angiography. The PD severity score was calculated by diseased segment (17 segments adapted from AHA) multiplying the severity (PD thickness: 3 for transmural, 2 for >50%, 1 for <50% and 0 for normal).
PD was identified in 32 of the 38 patients with ACS. The predominant pattern of PDs was transmural in STEMI (89%), non-transmural in NSTEMI (61%), and subendocardial in UA (45%). The sensitivity and specificity of PD for predicting IRA were 91% and 100%. Besides, the sensitivity and specificity of more than 50% thickness of PD involvement for detecting MI were 85% and 91%. A significant difference exists in waiting time for catheterization (p<0.00001) and PD severity score (p<0.001) between these three groups.
In patients with ACS, myocardial PDs detected on non-gated high-pitch aortic CTA provides high sensitivity and specificity with IRA related territory. Furthermore, PD with more than 50% thickness involvement contributes well sensitivity and specificity for myocardial infarct detection especially in patients with ACS.