Relation of distribution of coronary blood flow volume to coronary artery dominance.

Coronary artery dominance influences the amount and anatomic location of myocardium that is perfused by the left or right coronary circulation. However, it is unknown whether coronary artery dominance also influences the distribution of coronary blood flow volume. The aim of this study was to evaluate volumetric coronary blood flow in 1,322 vessels from 496 patients in the Prediction of Progression of Coronary Artery Disease and Clinical Outcomes Using Vascular Profiling of Endothelial Shear Stress and Arterial Wall Morphology (PREDICTION) study. Patients were divided into 2 groups (right-dominant and left-dominant or balanced circulation). Coronary blood flow volume was calculated by coronary segment volume measurement using angiography and intravascular ultrasound and the contrast transit time through the segment. Coronary blood flow in the left circumflex coronary artery was significantly higher in left-dominant or balanced circulation than in right-dominant circulation (113 ± 43 vs 72 ± 37 ml/min, p <0.001), whereas flow in the right coronary artery was significantly lower in left-dominant or balanced circulation than in right-dominant circulation (56 ± 40 vs 113 ± 49 ml/min, p = 0.003). There was no significant difference in the left anterior descending coronary artery. In conclusion, coronary artery dominance has an impact on coronary blood flow volume in the left circumflex and right coronary arteries but not in the left anterior descending coronary artery. These findings suggest that the extent of myocardial perfusion area is associated with coronary blood flow volume.