Development of a risk score for no-reflow phenomenon after percutaneous coronary interventions in patients with ST-segment elevation myocardial infarction

Background . No-reflow phenomenon during primary percutaneous coronary intervention (PCI) is a significant clinical problem in patients with ST-elevation myocardial infarction (STEMI), and its predictors remain unclear. Aim . To develop a scoring system to predict the risk of no-reflow in patients undergoing PCI for STEMI. Methods . Data were collected from 1280 consecutive patients with STEMI (59.2±11.4 years, 74.2% men, 5.2% no-reflow) who were admitted to the coronary care unit and underwent PCI. Baseline clinical, angiographic and procedural variables were used to develop the risk score in a training dataset (n=888, 70%) which was then validated in a test dataset (n=392, 30%). A credit risk assessment tool was used to construct a precise screening tool for no-reflow. Results . The model comprised age, pain to revascularisation time, neutrophil count, admission plasma glucose level, initial TIMI flow and direct stenting as the only independent predictors of no-reflow. These factors were weighted and used to develop a risk score ranging from 0 to 7. In the training dataset, the optimal threshold score for predicting no-reflow was ≥35, with 69% sensitivity and 81% specificity (area under the curve (AUC) = 0.84, p < 0.001). When these findings were applied to the test dataset, the AUC was 0.75 (p < 0.001), with 70% sensitivity and 80% specificity. Conclusion . The score developed in this study, based on clinical, angiographic and procedural features, can be used with acceptable accuracy to predict no-reflow in STEMI patients treated by PCI. Received 29 August 2019. Revised 25 March 2020. Accepted 16 April 2020. Funding: The study did not have sponsorship. Conflict of interest: Authors declare no conflict of interest.