[Factors related to the poor coronary collateral circulation in patients with coronary artery disease]

To explore the factors related to poor coronary collateral circulation (CCC) and the synergy effects among various factors in patients with coronary artery disease (CAD).

A total of 180 patients with coronary angiography confirmed CAD (at least one major coronary artery stenosis equal to or greater than 95%) were included in this study. Coronary collateral circulation was graded according to the Rentrop scoring system. There were in 54 patients with Rentrop 0 and 1 (poor CCC) and 126 patients with Rentrop 2 and 3 (good CCC). Clinical data including age, weight, gender, history of smoking, and factors that were known to influence the development of collateral s, such as hypertension, diabetes mellitus, fasting blood glucose (FBG), hemoglobin A1c (HbA1c), serum total cholesterol (TC), triglyceride (TG), high density lipoprotein cholesterol (HDL-C), low density lipoprotein cholesterol (LDL-C) and estimate glomerular filtration rate(eGFR) levels were also documented. Multivariate logistic regression was performed to detect possible factors related to CCC.

(1) FBG levels and the incidence of eGFR < 60 ml·min(-1)·1.73 m(-2) were significant higher in Rentrop 0 and 1 group than in Rentrop 2 and 3 group (P = 0.001, P = 0.034, respectively). (2) After adjusting for age, gender, smoking habits, hypertension, diabetes and dyslipidemia, FBG levels (OR = 1.374, P = 0.005) and eGFR levels (OR = 2.412, P = 0.013) remained as independent risk factors for CCC. (3) The ROC curve showed that the optimal cut-off point for FBG to predict poor CCC was 5.8 mmol/L. The area under the ROC curve was 0.656 (P = 0.001). (4) According to FBG and eGFR, patients were further divided into FBG ≥ 5.8 mmol/L and eGFR < 60 ml·min(-1)·1.73 m(-2) group (group A), FBG ≥ 5.8 mmol/L and eGFR ≥ 60 ml·min(-1)·1.73 m(-2) group (group B), FBG < 5.8 mmol/L and eGFR < 60 ml·min(-1)·1.73 m(-2) group (group C), and FBG<5.8mmol/L and eGFR ≥ 60 ml·min(-1)·1.73 m(-2) group (group D). The frequencies of poor CCC of the four groups were 51.7% (15/29) , 36.7% (18/49), 35.5% (11/31) and 12.7% (8/63) respectively (P < 0.001). After adjusting for age, gender, smoking habits, hypertension and dyslipidemia, the risk of poor CCC in group A, B and C patients were 7.494 (95%CI = 1.410-7.551, P = 0.001), 3.921 (95%CI = 1.061-6.910, P = 0.005) and 3.474 (95%CI = 0.160-4.477, P = 0.047) times higher than patients in group D.

Our results show that higher FBG levels and lower eGFR are independent predictors of poor CCC in CAD patients. Higher FBG levels and lower eGFR evoke a synergistic effect on poor CCC in CAD patients.