The Influence of Morphological Characteristics of lesions on the Development of Collateral Circulation in Angina Pectoris

Background:It is well known that collateral circulation has important roles in ischemic heart di- sease. It reduce ventricular remodeling and infarct size to improve ventricular function and survival. Extents and duration of ischemia are critical stimulants of the development of coronary collaterla circulation. We hypothesize that collateral circulation is poor in patients with lesions at branching points because atherosclerosis progress more rapidly not to allow the collateral circulation to develop. Method:We studied total 330 coronary angiography, which have more than 50% stenosis in any coronary artery, normal left ventriculography and no history of myocardial infarction. In each coro- nary angiography, severity, site, proximity, length of lesions were analyzed, classified, and collaterale circulation was graded. We also observed whether the lesions involve branching points or not. Results:While coronary collateral circulation developed well when stenosis was more than 90% in the severity, it was poor when the lesions involve branching points. Collateral circulation tended to be poor in case of eccentric lesions, but it was statistically insignificant. The above findings support our hypothesis of the accelerated atherosclerosis at branching points. Conclusions:The facts that the development of coronary collaterals is poor with lesions in- volving branching points suggest that atherosclerosis is accelerated at these lesions that is chara- cterized by blood stasis, turbulence and lower arterial wall tension.