Prognostic value of coronary collaterals in patients with acute coronary syndromes

Background The presence of good coronary collateral circulation (CCC) can protect and preserve myocardium from ischemia, increase myocardial contractility, and reduce adverse clinical events. However, its impact on mortality is still a topic of debate, particularly in acute coronary syndrome (ACS). The aim of this study was to investigate the association of CCC with cardiac risk factors and in-hospital mortality in patients hospitalized with a diagnosis of ACS. Methods The study population included 2286 patients with ACS who underwent coronary angiography and were found to have at least 90% significant lesion in at least one major coronary artery. The CCC was graded according to the Rentrop classification. The patients were classified into a poor CCC group (Rentrop grades 0-1, n = 1859) or a good CCC group (Rentrop grades 2-3, n = 427). Results Patients with good CCC had more high-risk patient characteristics such as older age, higher rate of Killip class of at least 2 at admission, lower left ventricular ejection fraction, and impaired renal functions compared with the patients with poor CCC. In multivariate analysis, the presence of good CCC [odds ratio (OR): 2.000; 95% confidence interval: 1.116-3.585; P = 0.020], left ventricular class of at least 2 at admission (OR: 3.609; P < 0.001), age of at least 65 years (OR: 2.975; P = 0.003), and hemoglobin (OR: 0.797; P = 0.003) were independent predictors of in-hospital mortality. Conclusion In contrast to previous studies, our study did not confirm a beneficial role of good CCC in patients with ACS; the presence of good CCC was even independently associated with increased in-hospital mortality in the multivariate analysis. Copyright (C) 2017 Wolters Kluwer Health, Inc. All rights reserved.