The Diagnostic Value Of Coronary Computed Tomographic Angiography In Detection Of Myocardial Ischemia In The Patients With Coronary Heart Disease Risk Equivalents

Objective:To evaluate the performance of coronary computed tomographic angiography(CCTA) in the patients with coronary heart disease risk equivalents who had no typical symptoms of myocardial ischemia for diagnosis of myocardial ischemia.Methods:The 100 patients with coronary heart disease risk equivalents who had no typical symptoms of myocardial ischemia were collecting continuously.CCTA and MPI were conducted.The degree of coronary stenosis is divided by CCTA into <50%,50% ~69%,≥70%.Corresponding myocardial imaging on MPI is divided into normal perfusion and abnormal perfusion,and the myocardial segments were located at the corresponding coronary vessels. To evaluate the performance of CCTA in the patients with coronary heart disease risk equivalents who had no typical symptoms of myocardial ischemia for diagnosis of myocardial ischemia and the results of MPI will be the gold standard.Results:(1) The results of detection from CCTA: Among the total 400 coronary vessels of100 patients,22 coronary arteries stenosis ≥50%, including 15 anterior descending coronary arteries,2 left circumflex coronary arteries and 5 right coronary arteries.The detection rate of coronary artery stenosis was 5.5%.(2) The results of detection from MPI: Among the total 100 patients,the myocardial segments were located at the corresponding coronary vessels, according to the segmentsof ischemic myocardium,including 16 anterior descending coronary arteries,2 left circumflex coronary arteries and 10 right coronary arteries.(3) Compare the results of detection from CCTA with MPI: Among the total 400 coronary vessels, 10(45.5%)coronary vessels performed perfusion defects on MPI;18 of378(4.8%)coronary arteries,in which coronary stenosis<50%,showed abnormal imaging on MPI.The positive results of CCTA were only 10 cases in accordance with the gold standard, accounting for 2.5% of the total number.But the positive detection rate of MPI was 7.0%, and the difference between the CCTA and MPI is significant(P<0.01).The negative detection rate of MPI was 93.0% and the correct negative detection rate checked out by CCTA was 90.0%,there was no significant difference between the CCTA and MPI.(4) The sensitivity,specificity,positive predictive value and negative predictive value of CCTA in detecting myocardial ischemia was 35.7% 、 96.8% 、 45.5% 、95.2%,respectively. As for the cut-off point of 50%,there was significant difference between the degree of coronary artery stenosis and the risk probabilities of corresponding myocardial ischemia.Conclusion:CCTA is an useful method for exclusion of myocardial ischemia in the patients with coronary heart disease risk equivalents who had no typical symptoms of myocardial ischemia,but with a low diagnostic performance.