Relationship of Frontal QRS-T Angle with Coronary Flow Grade and Adverse Events Before Percutaneous Coronary Intervention in Patients with Non-ST-Elevation Myocardial Infarction

Abstract

Objective: Electrocardiography is used in the initial risk assessment of patients with non-ST elevation myocardial infarction. The frontal QRS-T angle is an electrocardiography paramete that may be affected by the alterations in the coronary blood flow. This study aimed to explor the relationship of the frontal QRS-T angle with coronary flow grade and adverse events i non-ST-elevation myocardial infarction patients. Methods: A total of 191 non-ST-elevation myocardial infarction patients were divided int 2 groups based on the thrombolysis in myocardial infarction (TIMI) flow level on coronar angiography before revascularization, namely TIMI 0/1 and TIMI 2/3. The frontal QRS-T angl obtained before revascularization was compared between the groups and its relationship wit adverse events was examined. In-hospital all-cause mortality, repeat target lesion revascular ization, new-onset heart failure, ventricular arrhythmias, and atrial fibrillation were defined a adverse events. Results: Frontal QRS-T angle was wider in the patients with TIMI 0/1 flow compared to th patients with TIMI 2/3 flow (P < 0.001). The frontal QRS-T angle was determined to be predictor of TIMI flow grade 0/1 before revascularization in patients with non-ST-elevatio myocardial infarction (odds ratio: 1.51; 95% CI: 1.30-1.75; P < 0.001). The frontal QRS-angle was a predictor of the adverse events during hospitalization in the patients with non-ST elevation myocardial infarction (odds ratio: 1.11; 95% CI: 1.04-1.19; P = 0.002). The cut-o values of the frontal QRS-T angle for TIMI flow grade and adverse events were determined t be 73.5°, based on receiver operating characteristic curve analysis. Conclusion: Increased frontal QRS-T angle may be a useful electrocardiography parameter fo determining TIMI flow grade and the need for an early invasive strategy in patients with non ST-elevation myocardial infarction.