Relationship between plasma apelin level and coronary collateral circulation

Objective: The presence or absence of coronary collaterals is of vital importance during acute ischemia. Angiogenesis play an important role in coronary collateral vessel formation. In previous studies it is shown that apelin is a potential angiogenetic factor. But in these studies there is no data about apelin and coronary collateral circulation relationship. In our study our aim is to investigate the relationship between plasma apelin level and coronary collateral circulation in patients with coronary artery disease. Methods: One hundred and thirty two patients with stable angina pectoris who were performed coronary angiography and in which more than %90 obstruction detected in the proximal or medial segments of coronary arteries are included to our study (34 females, 98 men; average age: 63,5 ± 10,3 years). Coronary collateral degree was graded according to the Rentrop-Cohen classification. Patients with grade 2 or 3 collateral degree were included in the good collateral group (64 patients) and and the patients with grade 0 or 1 collateral degree were included in the poor collateral group (68 patients). Results: The plasma apelin level was significantly higher in the good collateral group (0.69±0.2 ng/dl vs 0.59±0.2 ng/dl, p<0.001). The serum nitric oxide (NO) level were similar between two groups (10.3±11.0 uM vs 10.2±9.6 uM, p=0,893). Patients who have extended stabile angina pectoris for 2 months or longer and current smoking were higher in the good collateral group. This finding was statistically significant for stabile angina pectoris (%79.7 vs %45.6 p<0.001), but not for current smoking (%46.2 vs %29.1 p=0.069). In multivariate analysis stabile angina pectoris (OR 4.072; CI %95 1.178-14.070; p=0.026), smoking (OR 4.442; CI %95 1.114-17.709; p=0,035) and plasma apelin level (OR 5.582; CI %95 1.517-20.545; p=0,01) were independent predictors of well-developed coronary collaterals. Conclusions: To best of our knowledge our study is the first investigation that shows higher plasma apelin level is related to better coronary collateral development. Demonstration of favorable affects of apelin on good collateral development may lead to include apeline in the antiischemic and prognostic treatment strategies which increases collateral development.