Marked Discordance Between Coronary Artery Calcium Score and Framingham Risk Score in Middle Eastern and Veteran American Populations

Background: Conventionally, the Framingham Risk Score (FRS) was used as a tool to risk stratify individuals for cardiovascular (CV) events and death. More recently, the coronary artery calcium score (CACS) has been used as a complimentary method for the assessment of CV risk. This study’s objective is to quantify the magnitude of marked discordance (MD) between FRS and CACS. The subjects were from two different ethnic groups, namely, a Middle Eastern population and a veteran American population. Methods: This is a retrospective observational cohort study of 499 consecutive patients who underwent multidetector cardiac computerized tomography (MDCT) at King Fahd Armed Forces Hospital (KFAFH), Jeddah, Saudi Arabia and Veterans Affairs Loma Linda Health Care System (VALLHCS). CACS was measured using the Agatston method. FRS was calculated by chart review. MD was defined as a CACS of <100 with a high risk FRS or a CACS of >400 with low risk FRS. Patients had CACS between 100 and 400 were excluded from the analysis. Results: A total of 499 patient CT studies were reviewed with 450 meeting study criteria,130 patients from the VALLHCS (63 ± 12, 95% males) and 320 from KFAFH (27% males). MD was found in 308 (68%) of the total number enrolled. In the American population, of the 62 patients with a CACS <100, 3% (2 patients) only had discordantly high FRS and of the 69 patients with a CACS >400, 20 patients (29%) had a discordantly low FRS. In the Middle Eastern population, of the 290 patients with a CACS <100, 281 patients (96.9%) had discordantly high FRS and of the 30 patients with a CACS >400, only 5 patients (16.7%) had a discordantly low FRS. Conclusion: The majority of MD in the Middle Eastern population had a high FRS with a low CACS. In contradistinction, the American veterans with MD had a high CACS and a low FRS.