Predicting no-reflow phenomenon prior to primary percutaneous coronary intervention using a novel probability risk score derived from clinical and angiographic parameters.

OBJECTIVE: We aimed to create a clinically usable probability risk score for prediction of no-reflow (NRF) phenomenon prior to primary percutaneous coronary intervention (PPCI). PATIENTS AND METHODS: This single-center and retrospective study included 1254 patients with acute ST-segment elevation myocardial infarction (STEMI) who underwent PPCI. Patients were randomly assigned into two groups in the ratio 2:1, the derivation dataset (n=840) and validation dataset (n=414). Independent predictors of NRF were identified and combined to create a prediction model using univariate and multivariate regression analysis in the derivation dataset. The risk score was tested and validated by calculating area under the receiver operating characteristic (ROC) curves in the derivation and validation datasets, respectively. RESULTS: Five significant, independent predictors of NRF were identified: age ≥ 65 years (odds ratio [OR]: 2.473, 95% confidence interval [CI]: 0.389-1.484, p < 0.01), heart rate ≥ 89 bpm (odds ratio [OR]: 1.622, 95% confidence interval [CI]: 0.024-0.945, p < 0.05), Killip class ≥ II (odds ratio [OR]: 1.914, 95% confidence interval [CI]: 0.024-1.306, p < 0.01), total ischemic time ≥ 268 min (odds ratio [OR]: 2.652, 95% confidence interval [CI]: 0.493-1.565, p < 0.01), and thrombus burden G≥4 (odds ratio [OR]: 8.351, 95% confidence interval [CI]: 0.344-15.901, p < 0.01). The risk score was created combining these predictors with assigned points. The overall score ranged from 0 to 17 points. The optimal cutoff value of the risk score was 11 points (area under curve [AUC]: 0.772, 95% confidence interval [CI]: 0.729-0.815, sensitivity 71.21%, specificity 70.34%, positive predictive value 30.92%, negative predictive value 92.91%, p < 0.001). The ROC curve for the validation group showed good discriminant power. CONCLUSIONS: We developed a novel risk score based on five clinical and angiographic parameters, which might be a useful clinical tool for prediction of NRF in STEMI patients prior to PPCI with an acceptable accuracy.