Predictive role of Frontal QRS-T angle and Selvester QRS Score in determining angiographic slow flow phenomenon following percutaneous coronary intervention in patients with Non-ST elevation myocardial infarction

Aim: Slow flow (SF) that develops after percutaneous coronary intervention (PCI) is significantly associated with poor prognosis in Non-ST elevation myocardial infarction (Non-STEMI) patients. Increased Selvester QRS score and Frontal QRS-T angle [f(QRS-T)] are related to adverse cardiovascular outcomes. We aimed to investigate the predictive role of the Selvester QRS score and f(QRS-T) for the development of post-PCI SF in patients with Non-STEMI.

Method and results: In a retrospective study, 210 patients with Non-STEMI were divided into two groups as SF (29) and Non-SF (181) according to their TIMI coronary flow grade. For all patients the Selvester QRS score and f(QRS-T) were calculated from automatic electrocardiography (ECG) reports. The mean age of the study population was 63 (55-75) years and 102 (68.6%) of patients were male. The Selvester QRS score and f(QRS-T) were higher in the SF group than in the Non-SF group [(5[3-8], 3[2-5]); (67° [42°-88°], 39° [24°-59°]), respectively, all p <0.01]. In a logistic regression analysis, the Selvester QRS score (OR = 4,862; 95% (CI) = 1,131-20,904, p =0.03) and f(QRS-T) (OR = 5,489; 95% (CI)= 11,433-21,034, p =0.01) were found independent predictors of post-PCI SF in Non-STEMI patients. Receiver operating characteristic (ROC) analysis was performed to assess the diagnostic values of the Selvester QRS score [86% sensitivity; 44% specificity; cut off 2; (AUC, 0.693)] and f(QRS-T) [62% sensitivity; 73% specificity; cut off 58°; (AUC, 0.778)].

Conclusion: The Selvester QRS score and f(QRS-T), both easy-to-calculate ECG parameters, are predictors of post-PCI SF in Non-STEMI patients.