Intermediate-Risk Chronic Stable Angina: Neutrophil-Lymphocyte Ratio and Fibrinogen Levels Improved Predicting Angiographically-Detected Coronary Artery Disease

BACKGROUND Coronary heart disease (CHD) is the leading cause of death worldwide. Research indicates that coronary atherosclerosis is the most frequent cause of CHD. Evidence is scarce concerning the clinical efficacy of fibrinogen or neutrophil-lymphocyte ratio (NLR) measurement in risk-stratifying patients with chronic stable angina. OBJECTIVES To examine the independent and incremental prognostic value of fibrinogen and neutrophil-lymphocyte ratio (NLR) for angiographically-detected coronary artery disease (CAD). PATIENTS AND METHODS In this cross-sectional study, angiography was performed for 183 Iranian patients with chronic stable angina with exercise ECG-determined intermediate risk. Generalized estimated equations were used to obtain the odd ratio (OR) of CAD for a 1-unit increase in log-NLR and a 1-SD increase in plasma fibrinogen. Models were adjusted for established CAD risk factors. Integrated discriminatory improvement index (IDI) and net reclassification improvement index (NRI) were used as measures of predictive ability for CAD, combined with traditional risk factors by NLR and fibrinogen. RESULTS The mean age of the participants was 57.5, with 51.9% being male. Only 12% of participants had angiographically-determined patent coronary arteries. The number of participants with one, two, and three-vessel stenosis were 76, 31, 31, respectively, while 45 did not have stenosed vessels. NLR and fibrinogen levels were significantly higher in patients with stenosis in two (2.4 and 512 mg.dL-1) or three (2.6 and 517 mg.dL-1) coronary arteries, as compared to the group of patients with no significant involvement (2 and 430 mg.dL-1) (all P < 0.01). Patients with a higher NLR and a higher fibrinogen levels were more likely to have higher grades of CAD. OR log-NLR = 1.36 (95% CI: 1.05 - 1.94) and OR Z-Fibrinogen = 1.61 (95% CI: 1.18 - 2.22). When NLR and fibrinogen were added to the traditional risk factors separately, the NRIs were 0.170 (0.023 - 0.324) and 0.380 (0.214 - 0.543), respectively. The NRI was 0.460 (0.303 - 0.620) when both NLR and fibrinogen added to traditional risk factors simultaneously. CONCLUSIONS NLR and fibrinogen predicted CAD, independent of traditional CAD risk factors. Both measures (whether separately or together) substantially enhanced the predictive performance of traditional risk factors for identifying patients with CAD.