Neutrophil-Lymphocyte Ratio May Predict the Degree of Coronary Collateral Circulation.

Abstract

We have intentionally read the article ‘‘The Relationship Between Neutrophil-to-Lymphocyte Ratio and Coronary Collateral Circulation’’ by Uysal et al. In that well-presented study, the authors aimed to determine the relationship between neutrophil-to-lymphocyte ratio (NLR) and development of coronary collateral circulation (CCC) in patients with stable coronary artery disease (CAD). They demonstrated an independent association between levels of NLR and development of CCC in patients with stable CAD. Coronary collateral circulation is an adaptive response to myocardial ischemia. Well-developed collaterals are associated with reduced mortality in patients with stable CAD and reduced infarct size in patients with acute myocardial infarction. In the present study, coronary collaterals were graded according to the Cohen-Rentrop method, grade 0, no filling of any collateral vessels; grade 1, filling of side branches of the artery to be perfused by collateral vessels without visualization of epicardial segment; grade 2, partial filling of the epicardial artery by collateral vessels; and grade 3, complete filling of the epicardial artery by a collateral vessels. In this study, patients with grades 0 to 1 and patients with grades 2 to 3 were classified as poor CCC and good CCC, respectively. However, although in some previous studies CCC was graded according to the Cohen-Rentrop method, classifications were applied differently. In this context, Refiker et al classified the study group as impaired CC development (group 1, Rentrop grades 0-1-2) and adequate CC development (group 2, Rentrop grade 3). And Duran et al accepted Rentrop grade 0 as absence of CC vessels and they accepted Rentrop grade 1 as presence of CC vessels. A subgroup analysis of Rentrop grading system according to each of the 4 groups might affect the results of the study. It would be better if the authors had added subgroup analysis according to Cohen-Rentrop method grading system, respectively. A complete blood count is a routine, easy, and cheap examination technique. As a simple and noninvasive marker, NLR, in part of blood count, is a recently emerged better reflector of inflammation and endothelial dysfunction which have been evaluated widely in several cardiovascular diseases. However, NLR can be affected by age, obesity, smoking, cardiovascular disease, malignancies, diabetes mellitus, hypertension, and inflammatory disease. Some recent studies have also presented that elevated NLR is linked with peripheral artery disease and stroke, all of which are related to atherosclerosis on the basis of inflammation. It can also be affected by thyroid and rheumatic diseases, hepatic diseases, and medications such as antihypertensive therapy. We believe that these findings will elucidate further studies about NLR as a surrogate marker of prognosis in patients with STEMI. The role of inflammatory markers in cardiovascular diseases has been extensively evaluated, and a consistent relationship between various inflammatory markers and cardiovascular diseases has been established in the past. In addition to NLR, high-sensitivity C-reactive protein, red cell distribution width, g-glutamyl transferase, and uric acid are also used as assessment markers in patients and clinical practice. The NLR together with other serum inflammatory markers is used as a significant clinical indicator, used as an inflammatory marker, and used in prediction of stress in human body.