Evaluating differences in diameter size of coronary arteries in Asian-Indians vs Caucasians using CT Angiogram Amgad Makaryus, Vidhi Patel, Rajiv Jauhar, Michael Qiu, Darius Jonasch, Saba Shariyar, John Makaryus, Ayneet Singh, Ali Abraham, Rolando Gomez, and Renee Pekmezaris
Background
Methods
People of South Asian descent have a higher rate of coronary artery disease with an earlier onset and worse outcomes than people of Caucasian descent. Previous studies by this group found evidence of smaller coronary artery diameters in Asian-Indian patients undergoing coronary angiography, and this study aims to corroborate these findings with a broader sample and updated imaging techniques.
We will identify Caucasian and Asian-Indian patients undergoing coronary CT angiography (CCTA) at NS Manhasset, NSUH, Lenox Hill & Southside, hospital between 09/01/15 and 08/31/20. Measurements of the proximal left main, left anterior descending, left circumflex, and the right coronary arteries will be taken. Demographics and conventional risk factors that could influence coronary size will also be assessed, including cholesterol levels, diabetes HbA1C, Lipoprotein A, hypertension, smoking, and diabetes.
Hypothesis We hypothesize that compared to Caucasian patients, the coronary arteries of Asian-Indian patients will have significantly smaller mean diameters even after correction for body surface area.
Previous Results
Study Design: Problems and Solutions The inclusion of an individual in the Asian-Indian cohort will require contacting the patient to confirm their ethnicity, but the individuals being contacted will be identified based on their name and the categorization of their race in the EMR. Depending on the accuracy of records, individuals may be overlooked. The population of individuals undergoing CCTA is less likely to have pathology than those being catheterized; however, there are likely subpopulations of patients imaged for different reasons. With a suitably large patient population, ideally, we will be able to control for these factors. With a large number of images to process, an efficient and replicable process for measurement will be necessary
Future Directions Representative images of coronary CT angiography (left) and standard angiography (right)
Considering the limitations of our previous study, changing to an assessment of CCTA images confers a number of advantages. First, the patients being imaged are less likely to be experiencing an acute coronary event as CCTA is more often used in screening; in this study of physiology, CCTA will provide a healthier and larger patient population. We will move from an evaluation of a few dozen patients to at several hundred. Calculating artery diameters from standard angiography requires assumptions about the image projection that may not be correct, while the 3D data of CCTA requires fewer assumptions. The trade in loss of resolution from CA to CCTA is not significant. CA is a lumenogram, while CCTA allows an evaluation of plaques which would change luminal diameter.
Besides future retrospective analysis on the data we will acquire, possible future questions include: • Can more specific demographic descriptors be determined for patient comparison? • Are there markers for differences in coronary artery size? • Within a patient population, do people of different ages maintain coronary physiology?
Resources Makaryus, A. N., Jauhar, R., Tortez, L. M., & Pekmezaris, R. (2017). Comparison of the Diameters of the Major Epicardial Coronary Arteries by Angiogram in Asian-Indians Versus European Americans. The American Journal of Cardiology, 120(6), 924-926. doi:10.1016/j.amjcard.2017.06.018 Makaryus A, Dhama B, Raince J, Raince A, Garyali S, Labana S, Kaplan B, Park C, Jauhar R. Coronary artery diameter as a risk factor for acute coronary syndromes in AsianIndians. Am J Cardiol 2005;96:778-780. Sharma R, Bhairappa S, Prasad SR, Manjunath CN. Clinical characteristics, angiographic profile and in hospital mortality in acute coronary syndrome patients in south Indian population. Heart India 2014;2:65-69.