Quantifying the impact of using Coronary Artery Calcium Score for risk categorization instead of Framingham Score or European Heart SCORE in lipid lowering algorithms in a Middle Eastern population

Hussain A Isma'eel; Mohamad M Almedawar; Bernard Harbieh; Wissam Alajaji; Laila Al-Shaar; Mukbil Hourani; Fadi El-Merhi; Samir Alam; Antoine Abchee

doi:10.1016/j.jsha.2015.05.004

Quantifying the impact of using Coronary Artery Calcium Score for risk categorization instead of Framingham Score or European Heart SCORE in lipid lowering algorithms in a Middle Eastern population

J Saudi Heart Assoc. 2015 Oct;27(4):234-43. doi: 10.1016/j.jsha.2015.05.004. Epub 2015 May 23.

Authors

Hussain A Isma'eel¹, Mohamad M Almedawar¹, Bernard Harbieh¹, Wissam Alajaji¹, Laila Al-Shaar², Mukbil Hourani³, Fadi El-Merhi⁴, Samir Alam¹, Antoine Abchee¹

Affiliations

¹ Department of Internal Medicine, American University of Beirut Medical Center, Beirut, Lebanon ; Vascular Medicine Program, American University of Beirut Medical Center, Beirut, Lebanon.
² Vascular Medicine Program, American University of Beirut Medical Center, Beirut, Lebanon.
³ Department of Radiology, American University of Beirut Medical Center, Beirut, Lebanon.
⁴ Vascular Medicine Program, American University of Beirut Medical Center, Beirut, Lebanon ; Department of Radiology, American University of Beirut Medical Center, Beirut, Lebanon.

Abstract

Background: The use of the Coronary Artery Calcium Score (CACS) for risk categorization instead of the Framingham Risk Score (FRS) or European Heart SCORE (EHS) to improve classification of individuals is well documented. However, the impact of reclassifying individuals using CACS on initiating lipid lowering therapy is not well understood. We aimed to determine the percentage of individuals not requiring lipid lowering therapy as per the FRS and EHS models but are found to require it using CACS and vice versa; and to determine the level of agreement between CACS, FRS and EHS based models.

Methods: Data was collected for 500 consecutive patients who had already undergone CACS. However, only 242 patients met the inclusion criteria and were included in the analysis. Risk stratification comparisons were conducted according to CACS, FRS, and EHS, and the agreement (Kappa) between them was calculated.

Results: In accordance with the models, 79.7% to 81.5% of high-risk individuals were down-classified by CACS, while 6.8% to 7.6% of individuals at intermediate risk were up-classified to high risk by CACS, with slight to moderate agreement. Moreover, CACS recommended treatment to 5.7% and 5.8% of subjects untreated according to European and Canadian guidelines, respectively; whereas 75.2% to 81.2% of those treated in line with the guidelines would not be treated based on CACS.

Conclusion: In this simulation, using CACS for risk categorization warrants lipid lowering treatment for 5-6% and spares 70-80% from treatment in accordance with the guidelines. Current strong evidence from double randomized clinical trials is in support of guideline recommendations. Our results call for a prospective trial to explore the benefits/risks of a CACS-based approach before any recommendations can be made.

Keywords: Canadian Cardiology Society guidelines; Coronary Artery Calcium Score; European Society of Cardiology guidelines; Lipid lowering therapy; Reclassification; Risk categorization.