A score system to predict no‐reflow in primary percutaneous coronary intervention: The PIANO Score

Abstract Background Angiographic no‐reflow is associated with poor outcomes in patients with ST‐segment elevation myocardial infarction (STEMI). We sought to develop and validate a score system to predict angiographic no‐reflow in primary percutaneous coronary intervention (PCI). Methods ST‐segment elevation myocardial infarction patients undergoing primary PCI were consecutively enrolled and were randomly divided into the training and validation set. Angiographic no‐reflow was defined as thrombolysis in myocardial infarction (TIMI) flow grade 0 to 2 after PCI. In the training set, independent predictors were identified by logistic regression analysis, and a score system (PredIction of Angiographic NO‐reflow, the PIANO score) was constructed based on the β‐coefficient of each variable. The established model was evaluated for discrimination and calibration. Results Angiographic no‐reflow occurred in 362 (17.8%) of 2036 patients. Age ≥70 years, absence of pre‐infarction angina, total ischaemic time ≥4 h, left anterior descending as culprit artery, pre‐PCI TIMI flow grade ≤1 and pre‐PCI TIMI thrombus score ≥4 were independent predictors of angiographic no‐reflow. The PIANO score ranged from 0 to 14 points, yielding a concordance index of 0.857 (95% confidence interval: 0.833 to 0.880), with good calibration. In the high‐risk (≥8 points) group, the probability of angiographic no‐reflow phenomenon was 38.7%, while it was only 4.8% in the low‐risk (<8 points) group. The score system performed well in the validation set. Conclusions We establish and validate a score system based on six clinical variables to predict angiographic no‐reflow in STEMI patients undergoing primary PCI, which may help choose the optimal individual treatment strategy.