Preprocedural systemic inflammatory response index and monocyte to lymphocyte ratio as a predictor of coronary slow phenomenon

Aim: To evaluate the potential of the systemic inflammation response index (SIRI) and the monocyte-to-lymphocyte ratio (MLR) as biomarkers for the coronary slow flow (CSF). Materials and Methods: The study included 235 participants, comprising 128 patients diagnosed with CSF and 107 individuals with normal coronary flow. SIRI and MLR were calculated for all participants, and coronary flow velocities were assessed using the TIMI frame count method. Results: CSF patients had higher SIRI (p=0.011) and MLR (p=0.039) versus controls. ROC analysis revealed MLR had 63.2% sensitivity, 50% specificity (AUC=0.577), while SIRI showed 29.6% sensitivity, 89.6% specificity (AUC=0.597). Conclusion: Elevated SIRI and MLR are independently associated with CSF, offering simple, cost-effective pre-coronary angiography (CAG) biomarkers. Though predictive accuracy is moderate, they may serve as tools for pre-CAG assessment in identifying CSF.