Prognostic Value of Coronary Artery Calcium in a Multi-Ethnic Asian Cohort

Objective: Coronary artery calcium (CAC) is associated with the presence of coronary atherosclerotic plaque and is a prognostic factor of cardiovascular events.CAC varies among ethnic groups in patients of the same age and gender.Studies on the prognostic value of CAC in a multi-ethnic Asian population have yet to be performed.We aim to study the association of CAC and ethnicity, all-cause mortality, and acute myocardial infarction (AMI). Materials and Methods:This is a retrospective study with a multi-ethnic cohort aged 35-84 years from a single tertiary institution between 2007-2017.The individuals were all clinically referred for cardiac CT calcium scanning.CAC was determined by Toshiba Aquilion One 320 Multi-detector Row CT (Toshiba Medical System).Results: This study had 65% males at an average age of 55 years.In our multivariable analysis of 16561 individuals, CAC is generally higher in the Malay than Chinese ethnic group [odds ratio (OR)=1.30,95% confidence interval (CI)=1.10-1.55]and did not differ among Indians and Chinese (p=0.400).Increasing CAC was associated with higher all-cause mortality (OR=1.27,95% CI=1.17-1.36)and AMI (OR=1.50,95% CI=1.35-1.66)after adjusting for known cardiovascular risk factors.Incorporation of CAC into a model with known cardiovascular risk variables enhanced prediction of all-cause mortality [area under the curve (AUC)= 0.78] and AMI (AUC=0.85). Conclusion:This study is the largest performed in a multi-ethnic Asian cohort.Malay ethnicity seems to confer a higher likelihood of coronary calcification compared to the Chinese and Indians.CAC was associated with higher all-cause mortality and AMI and complemented traditional cardiovascular risk factors in risk prediction, confirming its applicability in a multi-ethnic Asian population.