Background: Angiotensin II induces various growth factors such as vascular endothelial growth factor, platelet-derived growth factor, and fibroblast growth factor, and recent studies suggest that the expression of these growth factors promotes collateral growth. We hypothesized that the blockage of angiotensin II production by ACE inhibitors might interfere with collateral development in patients with coronary occlusion.
Methods: The study group consisted of 187 patients (114 males, mean ages, 62 +/- 11 years) who had chronic (> 1 month) coronary occlusion (TIMI flow grade < or = 1) in one of 3 epicardial coronary arteries. Collaterals were graded using the Rentrop classification, and the patients were divided into 2 groups according to having good (grade 2 and 3) or poor (grade 0 and 1) collaterals (n = 127 and 60, respectively). Clinical and angiographic characteristics were compared in the 2 groups.
Results: ACE inhibitor use (52% versus 35%, P = 0.04) and the prevalence of diabetes mellitus (DM) (43% versus 27%, P = 0.02) was higher in patients with poor collaterals. Patients with poor collaterals had a higher frequency of circumflex artery (Cx) occlusion, worse wall motion, and lower ejection fraction. In multivariate analysis, ACE inhibitor use (OR: 2.4; 95% CI = 1.23-4.68, P = 0.01) and the occlusion of Cx (OR: 3.3, 95% CI; 1.33-8.12, P = 0.01) were found to be independent predictors for poor collateral development, whereas there was a trend for DM as a predictor for poor collaterals (OR: 1.9, 95% CI = 0.97-3.8, P = 0.06).
Conclusion: The findings suggest that ACE inhibitor therapy may contribute to poor collateral development in patients with coronary occlusion.