Derived neutrophil-to-lymphocyte ratio as a predictor of no-reflow in ST-elevation myocardial infarction

AIMS: The no-reflow (NR) phenomenon is a serious complication of primary percutaneous coronary intervention (PCI) in ST-elevation myocardial infarction (STEMI), often reflecting distal embolization and microvascular obstruction, and representing a substrate for periprocedural (type 4a) myocardial infarction. NR has been linked to worse prognosis, including higher short- and long-term mortality. Inflammation is a key contributor to NR development. This study aimed to evaluate the relationship between the derived neutrophil-to-lymphocyte ratio (dNLR) and NR in STEMI patients undergoing PCI, and to assess its predictive value. METHODS: This retrospective, single-center observational study included consecutive STEMI patients undergoing primary PCI between May 2024 and May 2025. Patients were grouped based on post-procedural TIMI flow grade. Demographic, clinical, and laboratory parameters were compared. Regression and ROC analyses were performed. RESULTS: = 55). The NR group had significantly higher dNLR, C-reactive protein (CRP), glucose, creatinine, and troponin levels, along with lower left ventricular ejection fraction (LVEF). dNLR, diabetes mellitus, CRP and LVEF were independent predictors of NR. CONCLUSION: dNLR is a simple, cost-effective marker that may help identify patients at high risk of no-reflow in STEMI. Further prospective studies are warranted.