Determining the level of agreement for atherosclerotic cardiovascular disease risk stratification between coronary artery calcium score and traditional cardiovascular risk models

• Published in: Cardiovascular Journal of Africa Vol. 29; no. supp1; pp. 4 - 5
• Main Author: Kuria, Menge Issa
• Format: Journal Article
• Language: English
• Published: Clinics Cardive Publishing 26.04.2018
• ISSN: 1995-1892; 1680-0745

Introduction: Estimation of the risk of future cardiovascular (CV) events is an important step in the management of cardiovascular diseases. A number of CV risk tools are currently available for use such as the Framingham Risk Score (FRS), the American College of Cardiology/American Heart Association (ACC/AHA) pooled cohort equations and the World Health Organization /International Society of Hypertension (WHO/ISH) prediction charts. Unfortunately, none of the current available risk tools is based on Kenyan data or has been validated in Kenyans. This study therefore sought to compare the accuracy of FRS and ACC/AHA in a Kenyan population. The risk estimates derived using these algorithms were correlated with coronary artery calcium score (CACS), a well-established reliable predictor of future risk of CV events. Objective: To determine the level of agreement between coronary calcium score and traditional cardiovascular risk models for coronary artery disease risk stratification in a multi-ethnic population at a tertiary institution in Kenya.  Design: A cross-sectional study Methods: Data was collected retrospectively from the medical records of 200 patients referred to the Radiology department for a CT coronary artery calcium score. However, only 190 patients met the inclusion criteria were included in the analysis. Risk stratification comparisons were done according to CACS, FRS, ACC/AHA and WHO/ISH and the agreement (Kappa) and correlation (spearman rho) between them were calculated. Statistical significance was set at p 0.191) between CACS and the clinical CVD risk models. In relation to this, 83.6% of the intermediate risk group according to FRS were down-classified by CACS while 9.1% of the same cohort were up-classified to high risk by CACS. Conclusion: The poor agreement between CACS and the clinical CVD risk scores suggests that the clinical CVD risk tools currently used in our Kenyan population might be incorrectly stratifying risk in patients. A prospective study is needed to help improve risk predictions and set appropriate population-wide thresholds that are necessary to facilitate better clinical decision making.