Use of neutrophil/lymphocyte ratio as a marker in patients with suspicious diaphragmatic attenuation artifact

Objective: This study aimed to evaluate whether neutrophil/lymphocyte (N/L) ratio assists in the diagnosis of coronary artery disease (CAD) in patients with suspected diaphragmatic attenuation artifact (DAA) on myocardial perfusion SPECT (MP-SPECT).Material and Methods: A total of 255 patients undergoing coronary angiography between 2015-2020 due to unclear DAA of the inferior wall on MP-SPECT were included in this retrospective study. Patients were divided into two groups (CAD and non-CAD) according to angiographic images. Significant CAD was defined as ≥50% stenosis of coronary arteries feeding the inferior wall. White blood cell count, biochemical parameters, and risk factors for CAD were compared between the two groups.Results: There was no statistically significant difference between the two groups in terms of age (p = 0.055), gender (p = 0.482), and body mass index (p = 0.305). N/L ratio (OR = 1.397 p = 0.002 95% Cl = 1.128-1.732) and left ventricle ejection fraction (OR = 0.896 p = 0.023 95% Cl = 0.815-0.985) were independent risk factors for CAD in multivariate binary logistic regression analysis. Receiver Operating Characteristic (ROC) curve analysis showed that a cut-off value of ≥2 for N/L ratio predicted the presence of CAD (sensitivity=63.5%, specificity=60.7%, AUC=0.668, 95% CI=0.596 – 0.740, p<0.001).Conclusion: N/L ratio is a simple and accessible test and may increase the diagnostic accuracy of MP-SPECT for CAD in patients with suspicious diaphragmatic attenuation on MP-SPECT.