Study of estimation of coronary artery calcium by multi-slice spiral CT scan in post myocardial infarction cases

Abstract

Background: Strong relationship has been demonstrated between the presence of occlusive CAD and coronary artery calcification (CAC) detected at autopsy, fluoroscopy and computed tomography (CT scan). CT scan quantifies the relative burden of CAC deposits as a marker of atherosclerosis. Study explored utility of multi-slice spiral CT scan for detection of CAC in post myocardial infarction cases.Methods: Fifty-one post myocardial infarction cases were enrolled in the study. Detailed clinical history was recorded in every case regarding age, sex, history of risk factors for CAD like systemic hypertension, diabetes mellitus, smoking and family history of CAD. Every case was evaluated for fasting and postprandial blood sugar and fasting lipid profile. Body mass index (BMI) was also calculated. Coronary artery calcium was estimated in each patient by multi -slice spiral CT scan. Conventional angiography was also undertaken in 18 patients. Co-relation of coronary calcium with different age groups, sex, risk factors, electrocardiography and angiography was drawn.Results: Out of 51 cases scanned, 40 cases (78.4%) had detectable CAC. In 30 cases (58.8%), CAC score ranged from 1 to 100 (mild score); 6 cases (11.8%) had score between 101-400 (moderate score) while in 4 cases (7.8%) CAC score was more than 400 (severe score %). For detection of angiographically detectable disease, the sensitivity of multi-slice CT was 100% and the specificity was 33.3%.Conclusions: CAC is a valid measure of atherosclerotic plaque burden and is recommended as a screening tool for demonstrating significant atherosclerosis in susceptible subjects.