Prediction of no-reflow and major adverse cardiovascular events with a new scoring system in STEMI patients

Background: No-reflow is associated with a poor prognosis in STEMI patients. There are many factors and mechanisms that contribute to the development of no-reflow, including age, reperfusion time, a high thrombus burden, Killip class, long stent use, ejection fraction ≤40, and a high Syntax score. In this study, we aimed to evaluate the parameters associated with no-reflow prediction by creating a new scoring system. Methods: The study included 515 consecutive STEMI patients who underwent PCI; 632 STEMI patients who had undergone PCI in another center were included in the external validation of the scoring system. The correlations between 1-year major adverse cardiac events and low/high risk score were assessed. Results: In this study, seven independent variables were used to build a risk score for predicting no-reflow. The predictors of no-reflow are age, EF ≤40, SS ≥22, stent length ≥20, thrombus grade ≥4, Killip class ≥3, and pain-balloon time ≥4 h. In the derivation group, the optimal threshold score for predicting no-reflow was >10, with a 75% sensitivity and 77.7% specificity (Area under the curve (AUC) = 0.809, 95%CI: 0.772-0.842, P < 0.001). In the validation group, AUC was 0.793 (95%CI: 0.760-0.824, P < 0.001). Conclusion: This new score, which can be calculated in STEMI patients before PCI and used to predict no-reflow in STEMI patients, may help physicians to estimate the development of no-reflow in the pre-PCI period.