Abstract
We read with great interest the article “Relation of neutrophil to lymphocyte ratio with the presence and severity of stable coronary artery disease” by Kaya et al. 1 They aimed to investigate the relationship between the severity of coronary atherosclerosis assessed by SYNTAX score (SS) and the neutrophil-to-lymphocyte (N/L) ratio in patients with stable coronary artery disease (CAD) as a novel, simple, and reli-able indicator of inflammation. They concluded that the there exists relation between N/L ratio and the severity and complexity of CAD assessed by SS in stable patients with CAD who underwent coronary angiography. To our knowledge, the present study is the first report evaluating the relationship of N/L ratio with the severity and complexity of CAD by SS in patients with stable CAD. They suggested that N/L ratio appears to be a promising marker that might be used more commonly in the follow-up of patients with CAD in the near future. Thanks to the authors for their contribution.
The SS is used for grading coronary complexity based on angiographic visual assessment. The severity of the coronary atherosclerosis in clinical practice has been recommended. Many studies have reported that elevated SS (ie, increased coronary complexity) is associated with higher rates of long-term major adverse cardiovascular events and revascularization after percutaneous coronary intervention or coronary artery bypass graft. 2
A complete blood count is an easy examination technique that gives us information about the patient’s formed blood contents such as the red and white cells, the platelets, the count and dimensions of the subgroups of cells and parameters such as the distribution weights and mean platelet volume. 3 As we know, bacterial infections and steroid usage can increase neutrophil counts, when especially viral infections may cause increase in lymphocyte counts. In recent years, N/L ratio has been proposed as a surrogate marker for endothelial dysfunction and inflammation in distinct populations and has prognostic and predictive values. 4,5 Although white blood cells are in normal range, subtypes of white blood cells may predict cardiovascular mortality. However, sometimes acute conditions like bacterial or viral infections or drug treatments might affect the neutrophil and lymphocyte counts, and so the ratio of these 2 parameters might be changed. The acute disease situation may overlap the chronic ongoing inflammation.
Pentraxin 3 (PTX3) is a recent candidate immunoinflammatory marker that has been reported to be associated with cardiometabolic risk factors and to predict adverse outcomes in individuals with cardiovascular disease. The PTX3, a novel inflammatory marker, plays a major role in vascular microinflammation and endothelial dysfunction, which are listed among the causes of cardiovascular morbidity and mortality and are found associated with the prognosis of cardiovascular outcomes. 6 Furthermore, PTX3 was more closely associated with the complexity and the severity of CAD than high-sensitivity CRP and was found to be an independent predictor for high SS. 7 For this reason, if further studies evaluate the PTX3 level in patients with CAD, it may contribute to the literature.
Additionally, they used modification of diet in renal disease (MDRD) formula for glomerular filtration rate (GFR). However, MDRD formula may measure higher GFR in younger age groups in comparison with the Cockcroft-Gault equation, but it can measure lower GFR in older individuals compared to the Cockcroft-Gault equation. 8 For this reason, it may be useful, and the result of the study may be different if the authors had used Cockcroft-Gault equation due to these factors.
We believe that these findings will elucidate further studies about N/L ratio as a surrogate marker of endothelial dysfunction and inflammation in patients with CAD. Finally, N/L ratio itself without other inflammatory markers may not give information to clinicians about the chronic endothelial inflammatory condition of the patient. So, we think that it should be evaluated together with other serum inflammatory markers.