Neutrophil Percentage to Albumin Ratio as a Predictor for Coronary Slow Flow Phenomenon in Patients with Myocardial Ischemia with No Obstructive Coronary Arteries.

Background: Accumulating evidences suggest that low-grade inflammatory response plays a key role in the pathophysiology of coronary slow flow phenomenon (CSFP). As a new hematological inflammatory indicator, the neutrophil percentage to albumin ratio (NPAR) and its role in the occurrence and development of CSFP remains unclear. In this study, we aimed to investigate the predictive value of NPAR in the presence of CSFP in patients with myocardial ischemia and no obstructive coronary arteries (INOCA).

Methods: In total, 1323 individuals with INOCA were included in this study. 85 patients developed CSFP were included in the CSFP group. 1:2 age-and sex-matched patients were selected from the absence of CSFP, with normal blood flow, as the control group. Clinical characteristics, laboratory parameters, and angiographic findings were compared between groups. NPAR was also calculated to explore its relationship with CSFP.

Results: NPAR was significantly higher in the CSFP patients than in the controls (19.3±2.5 vs 16.7±1.8, p<0.001). The NPAR increased with the number of coronary arteries involved in CSFP. Multivariate logistic regression analysis showed that an elevated NPAR level was an independent predictor of CSFP (OR 1.915, 95% CI 1.612-2.275, P < 0.001). The ROC curve showed that when NPAR was > 17.39, the sensitivity and specificity were 90.6% and 78.8%, respectively, and the area under the ROC curve (AUC) was 0.860 (95% CI: 0.811-0.909, P < 0.001). The AUC of neutrophil percentage was 0.845 (95% CI: 0.794-0.897, p < 0.001), and that of albumin was 0.808 (95% CI: 0.753-0.864, p < 0.001).

Conclusion: Elevated NPAR levels are an independent predictor of CSFP in patients with INOCA. NPAR could improve the predictive value of CSFP compared with neutrophil percentage or albumin ratio alone.