Exercise Electrocardiography Testing in Patients with Calcific Non-obstructive Coronary Lesions at Cardiac Multislice Computed Tomography

Background: Non-obstructive coronary artery disease (NoCAD), cardiac syndrome X (CSX), conduit vessel endothelial dysfunction and microvascular angina are all terms used to describe patients that have chest pain yet no obstructive coronary artery disease on coronary angiography. Objectives: the purpose of this study was to evaluate exercise ECG (Ex-ECG) test in patients with subclinical atherosclerosis who were diagnosed by multi-slice computed tomography (MSCT) coronary angiography to have nonobstructive lesions. Patients and Methods: 100 patients were recruited in the current study (their age ranged from 30 – 66 years), they were classified into three groups: group (A) 30 patients with non-calcific normal coronaries by MSCT, group (B) 35 patients with non-calcific non-obstructive lesions (zero calcium score) by MSCT and group (C) 35 patients with calcific non-obstructive lesions (calcium score < 400 HU) by MSCT. Results: There was statistically highly significant difference between the three groups as regard results of exercise ECG test (P value=0.001). Positive exercise ECG test results occurred with calcific and mixed plaques in group (C) more than soft plaque in group (B), and there is significant difference between two groups with (P-value = 0.001). Positive exercise ECG test results in group (C) occurred more frequently with higher calcium score ranged from (59 – 362) HU. Conclusions: MSCT angiography and calcium scoring system can provide valuable results which is helpful in avoiding an extra unnecessary invasive coronary angiography in patients for whom exercise ECG test results seemed to be positive or for whom high cardiovascular mortality risk from ischemia is not present.