Association Between Left Anterior Descending Artery Length with Coronary Artery Dominance: An Angiographic Study

Introduction: Although left anterior descending (LAD) artery supplies a large portion of the myocardium, the amount of blood supply provided by LAD is depended on the length of the LAD. The aim of the current study was to evaluate the association between coronary artery dominance and LAD anatomic types in patients with normal epicardial coronary arteries. Methods: This retrospective study was conducted at a tertiary teaching hospital on a total of 252 patients with normal coronary artery angiographic findings between April 2018 to March 2019. Patient’s medical records were utilized to collect demographic and catheterization data, as well as their clinical characteristics. Qualitative and quantitative catheterization data, including the anatomical type of LAD, dominance, LAD slow flow phenomenon, LAD ectasia, and Muscle Bridge were obtained from the angiographic examination. The three anatomical LAD types, including type I (LAD terminating before the apex), type II (LAD reached the apex), and type III (LAD wrapping around the apex) were compared in the left and right dominant coronary artery patients. Results: The mean age of patients was 58.06±10.89 years (age range: 27-79 years). The slow flow phenomenon was more significantly observed in patients with type C LAD (P=0.015); however, there was no significant difference between LAD types regarding LAD Muscle Bridge (P=0.099) and ectasia (P=0.810). In total, 54.8% and 45.2% of the patients had right and left dominant coronary artery systems, respectively. Moreover, there was a statistically significant association between wrap-around LAD and left coronary artery dominance (P<0.001). Conclusion: The type C LAD is more prevalent in patients with left dominant coronary artery.