Aim of the studyAtherosclerosis represents active inflammation in which leukocytes play significant role. Coronary collateral development is a response to myocardial ischaemia. In this study we aimed to investigate the association of the leukocytes with coronary collateral development in patients with non ST-elevated acute coronary syndromes (NST-ACS).Material and methodsA total of 251 consecutive patients were hospitalized in our hospital with a diagnosis of NST-ACS. The blood samples were collected 1-hour after admission to the hospital and peripheral leukocytes (neutrophils, monocytes and lymphocytes) were examined. All patients underwent coronary angiography. The coronary collateral vessels (CCV) are graded according to the Rentrop scoring system.ResultsGroup 1 consisted of 146 patients with Rentrop 0 and Group 2 consisted of 105 patients with Rentrop 1, 2 and 3. The presence of CCV was significantly associated with neutrophil count, lymphocyte count, monocyte count and neutrophil-lymphocyte ratio (NLR). In subgroup analyses, higher NLR was significantly associated with good CCV development in patients with NST-ACS.ConclusionsHigher neutrophil count, monocyte count and NLR and lower lymphocyte count on admission, were associated with the presence of CCV in patients with NST-ACS. High NLR may predict good collateral development in patients with NST-ACS.