The great advances in managing patients with coronary artery diseases enable treatment of these patients to be guided by coronary artery angiogram. Such improvement in the angiographic analysis is required to allow more effective application of information that depends on the coronary angiograms for the patients' diagnosis and therapy with ischemic coronary syndromes1. There is great variability in the dimensions of the coronary arteries in the average population2. The study of coronary artery variations, especially the left main coronary artery, can help the clinician plan interventional procedures such as stenting, balloon dilatation, or graft surgery.3 The main left coronary artery (MLCA) is shorter and larger than the right coronary artery 4. Usually, it is the first vessel to show blockages. It has a wide variability in its morphology regarding caliber, length, and the number of branching from the main trunk. These variations should be considered, not as anatomical characteristics only but also in interpreting different clinical events and the corresponding intervention maneuvers. The left coronary artery's mean diameter was reported to range from 3.0 to 6.8mm (4.64 ± 1.03)5. These wide variations are present in different branching patterns. The variation is also due to the effect of ethnicity, gender, age groups, and health condition. There is a lack of reports about the diameters of the left main coronary artery and its branches in the Sudanese population. This study covers this part and also contributes to the worldwide reports in this field. The objective of the study is to determine the angiographic diameters of the main left coronary artery, the left circumflex artery, and the anterior descending artery. It also aims to set a correlation between the diameters of these arteries and other variables like age, sex, surface area, and health problems.

This is a descriptive retrospective study of coronary angiography. The participants were 441 patients of both sexes. All the patients were above 18 years old and all without congenital heart diseases. Those patients were visitors of 3 Heart Centres in Khartoum State, Sudan. In each patient, a catheter was inserted, and dye was injected into coronary arteries, and X-Ray images were taken from different angles. Measurements of the diameters of the left coronary artery, the left circumflex artery, and the anterior descending artery were taken by 2 independent readers, with negligible variability. Ethical approval was obtained from the Heart centers, and history of personal data and health status was collected from the records. Mean, and standard deviation was calculated for each reading. ANOVA, Mann–Whitney U, and t-Tests were used to calculate the correlations (p-value of .05 or less was considered significant).

This study provided insight into the diameters of the left coronary artery (LCA) and its main branches in 441 cases. Measurements were collected from Coronary angiography, supported by personal and clinical data where relevant. The left coronary artery (LCA) diameter in this study was found in the range between 2.90 to 4.90mm, with an average of 3.96 mm for Sudanese. The (LCA) average lumen diameter of the (LCA) was reported 4.4± 0.4mm in an American study6, 3.8±0.8 mm in an African study 5, and 4.64 ± 1.03 mm in an Indian study3. The diameters of the left circumflex artery (CIR) and anterior interventricular (descending) artery (AI) in Sudanese were found to be 2.74 and 2.78 on average, respectively. This could be compared to an American report of 3.6±0.73. And 7±0.5 respectively7. The size of coronary vessels is influenced by factors such as age, sex, body weight, body surface area, weight of the heart, and ethnicity/race8.However, it was reported that there was no correlation between the length of the LCA and its diameter; it also showed no correlation between the diameter of the LCA and its angle of division9. In our study, most of the factors such as ethnicity, gender, age, and health conditions have a significant effect on the variations of the diameters of the three arteries, with p-value less than .05. Exceptions were the sex effect on (LCA) and (CIR), BMI effect on (CIR), and coronary diseases effect on (CIR), which seemed to have less significant effects. In 1992 a study from South Africa 5 reported no statistically significant difference between sexes (p= 0.696). This was true for Sudanese in our study regarding the (LCA) and (CIR), but could not be applied to the (LI). However, another study from New England, only one year later from that of South Africa, stated that the mean luminal diameters of the coronary arteries were larger among men than among women10. The definition of the severity of coronary arterial narrowing depends on proper knowledge of the range of the average size of the coronary arterial tree11. It has been reported that patients with small vessels are at a higher risk of having an adverse outcome following coronary stent placement due to a higher incidence of re-stenosis 12. In coronary artery bypass surgery, the most important factor in predicting the success of the operation is the size of the vessel to which the bypass is anastomosed 13

Hypertension in our study has a highly positive effect on the diameter of the left coronary artery. It may be on all coronary circulation, although a previous study on multivariate analysis demonstrated that hypertension has less effect 14. The BMI and obesity likewise may have effects on coronary vessels variable with body effort and level of stress, but, despite increased technical difficulty caused by obesity, it is not an independent risk factor 15. The effect of coronary artery disease on the diameter of the main left coronary artery. It may be on the other coronary vessels could be explained by the significant changes in resting and reactive hyperemic coronary flows and resting pressure gradients occurred as the length of a given degree of narrowing of the artery was increased 16.

Measurements of the diameters of the Left Coronary Artery (LCA), the left circumflex artery, and the anterior descending artery revealed much variations among the Sudanese population. The variations are due to age, gender, BMI, coronary artery disease, smoking habits, and hypertension.