Prevalence and Distribution of Coronary Dominance and Ramus Intermedius in North Indian Population on CT Coronary Angiography- A Cross-sectional Study

Abstract

Introduction: The Computed Tomography (CT) coronary angiography is a non invasive method to evaluate coronary artery stenosis in patients presenting with cardiac symptoms. It can also be used to decide coronary artery dominance which has various clinical implications like relatively higher death rates in left dominant coronary circulation. The most common variation of left coronary artery is ramus intermedius seen in approximately 30% of cases. Aim: To find the type of coronary artery dominance in male and female patients and to look for the prevalence of ramus intermedius in patients undergoing CT angiography for coronary artery disease following cardiac symptoms and to look for predominance based on gender if any. Materials and Methods: This cross-sectional study was done on 161 patients who visited the Department of Radiodiagnosis, Dr Ram Manohar Lohia Institute of Medical Sciences, Lucknow, Uttar Pradesh, India from January 2020 to October 2020 for CT coronary angiography on 64 slice CT scan machine and were evaluated for the type of coronary dominance and the presence or absence of ramus intermedius. Results: Of 161 patients (108 males and 53 females), right, left and co-dominance was present in 77%, 14.9%, and 8%, respectively with no significant difference between the sexes. Ramus intermedius was present in 20.4% cases, it was found to be more in males (16.77%) compared to females (3.73%). significantly more in males (Chi-square=4.0820, p=0.0430), and co-dominance (Chi-square=6.2930, p=0.0430). Conclusion: Right dominance was found to be in a greater number of subjects as compared to left dominance and co- dominance with no significant difference between both the sexes. Ramus intermedius came out as a common variation and is significantly more in co-dominance.