A Risk Score for No Reflow in Patients With ST‐Segment Elevation Myocardial Infarction After Primary Percutaneous Coronary Intervention

ABSTRACT Background Many factors are associated with no‐reflow (NRF) phenomenon in ST‐segment elevation myocardial infarction (STEMI), including plasma glucose, age, and pre–percutaneous coronary intervention (PCI) thrombus score. Initial clinical assessment would benefit from accurate NRF prediction. This study aimed to develop a simple scoring system to predict the risk of NRF in patients undergoing primary PCI with STEMI. Methods Baseline clinical and procedural variables were used for risk score development (the training dataset, n = 912) and validation (the test dataset, n = 864). Independent predictors of NRF from the multivariable model were assigned integer weights based on their coefficients and incorporated into a risk score. The discriminant ability of the score was tested by receiver operating characteristic analysis using the test dataset. Results The final model included 7 significant variables, which were age, pain‐to‐PCI time, neutrophil count, admission plasma glucose level, pre‐PCI thrombus score, collateral circulation, and Killip class. All these variables were then used to build a risk score in terms of the prediction of NRF. Receiver operating characteristic analysis demonstrated good risk prediction with a c statistic of 0.800 (95% confidence interval: 0.772‐0.826) in the test dataset. Conclusions In patients with STEMI treated by primary PCI, incidence of NRF phenomenon may be predicted with an acceptable accuracy based on a 7‐item simplified risk score.