Background: Conflicting reports exist on the influence of coronary collateral circulation on preservation of left ventricular systolic function. The aim of this study was to assess the effect of coronary collateral circulation on left ventricular systolic function in coronary artery disease.
Methods: Seventy-one consecutive patients having left anterior descending arteries with proximal or near-proximal stenosis of at least 95% (excluding 100%) were included in the study. The coronary collateral circulation to left anterior descending artery was evaluated with regard to its effects on left ventricular systolic function.
Results: Among the 71 patients, 46 patients were found to have a coronary collateral circulation grade of >or=1 (group 1), whereas the remaining 25 patients had coronary collateral circulation grade of 0 (group 2). The mean value of left ventricular function score in group 1 was higher than that of group 2 (3.69+/-2.34 vs. 2.00+/-1.55, P=0.002), whereas the mean value of left ventricular ejection fraction in group 1 was lower than that of group 2 (44.67+/-12.05 vs. 54.32+/-10.22, P=0.001). The value of coronary collateral circulation grade was found to be positively correlated with the value of left ventricular function score (P=0.01, r=0.3), and negatively correlated with the value of left ventricular ejection fraction (P=0.01, r=-0.3).
Conclusion: Coronary collateral circulation to the severely stenotic left anterior descending artery was not found to have an improving effect on left ventricular systolic function. In contrast with the previous studies demonstrating the coronary collateral circulation-associated preservation of left ventricular systolic function, presence of coronary collateral circulation was found to accompany or be associated with impairment of left ventricular systolic function. The grade of coronary collateral circulation was also found to be positively correlated with the severity of left ventricular systolic dysfunction. Further research on larger patient populations based on a long-term follow-up is warranted to investigate this issue.