The Development of Collateral Circulation in Patients with Total Occlusion of Coronary Artery and its Clinical Significance

Lee, Sang Hyun

Abstract

BACKGROUND AND OBJECTIVES: Coronary collateral circulation is known to have beneficial effects in patients with angina pectoris and myocardial infarction. The purpose of this study is to determine the predictors of collateral vessels development, the pathways of collateral circulation and the changes in collateral flow after coronary intervention and its functional significance in patients with total occlusion.
MATERIALS AND METHODS
One hundred thirty five patients who underwent coronary angiogram between Jan '97 and Dec '97 in Chonnam University Hospital (out of 3,264 cases) had total occlusion of one coronary artery were classified into two groups: angina pectoris (Group I:50 M, 19 F, 62.4+/-11.0 years) and acute myocardial infarction (Group II: 47 M, 19 F, 62.0+/-9.5 years).
RESULTS
Among 135 patients, 123 patients had collateral circulation. Collaterals were more frequently observed and better developed (grade 2 or 3) in Group I than Group II. Proximal and ostial lesions were associated with well developed collaterals. Collateral circulation was more frequently observed and well developed in proportion to the duration of angina in Group I. In 123 patients with collateral circulation, 247 collateral circulations were observed. Right coronary artery (RCA) and Left circumflex coronary artery (LCX) were more frequent recipient arteries than left anterior descending coronary artery (LAD)(RCA:2.20+/-1.02, LCX:1.88+/-0.94, LAD:1.29+/-0.8 respectively, RCA vs. LAD:p<0.001, LCX vs. LAD:p=0.014). Coronary interventions were performed in 50 out of 135 patients, collateral flow of Group II decreased much more than Group I after intervention (Group I: 5/14, Group II: 24/36, p=0.046). The wall motion score was lower in patients with well developed than poorly developed collaterals (20.7+/-4.91 vs. 23.7+/-6.22, p=0.015).
CONCLUSION
Proximal or ostial lesion and duration of angina are major predictive factors for the development of collateral circulation. Collateral circulation is associated with preserved myocardial contractility.After coronary intervention in patients with acute myocardial infarction, recruitment of preexisting collaterals may be more important mechanism rather than neoangiogenesis.