Coronary Artery Calcium Score and Framingham Risk Score in Symptomatic Indian Population-Any Correlation with Coronary Artery Disease Severity?

Abstract

Introduction: Coronary Artery Disease (CAD) is the most important reason of morbidity and mortality worldwide. Measurement of coronary calcification with the help of CT-based Coronary Calcium Score (CCS) is a considerable indicator of coronary atherosclerosis and correlates well with the risk for future cardiovascular events. Aim: To evaluate the relationship between CCS and the presence of significant CAD in low to intermediate risk in Indian subjects with cardiac chest pain undergoing CT Coronary Angiography (CTCA). In addition, we sought to identify the additive value of the CCS to the traditional Framingham Risk Score (FRS) in an Indian population. Materials and Methods: Multi-centric prospective study was conducted in subjects referred for CTCA due to cardiac chest pain. Patients were excluded if they had Coronary Artery Bypass Graft (CABG), Percutaneous Transluminal Coronary Angiography (PTCA), previous myocardial infarction and other CTCA contraindications. Scans were performed on a 128-slice MDCT with contemporary protocols. CCS and CAD severity were classified as per Society of Cardiovascular Computed Tomography (SCCT) guidelines. Significant CAD (>70% stenosis of epi-cardial coronary artery or >50% of left main coronary artery). FRS was calculated to predict long term risk of CAD. Results: We enrolled a total of 306 subjects (52±9 years; 59% males). The mean CCS was 79±10 AU. Significant CAD was present in 44 of the 99 subjects (44%) with a CCS=0 who were classified as low risk by FRS and 16 of 20 subjects (80%) who had an intermediate risk FRS and a CCS=0 AU had significant CAD on CTCA. There was no correlation between FRS and presence of significant CAD. Conclusion: Unlike Western countries, low CCS have poor correlation with absence of CAD in this population, whereas in the present study there was no relation between FRS and presence of CAD.

Keywords

• atherosclerosis
• coronary calcification
• stenosis