Abstract Body (Do not enter title and authors here): Objective: For patients with non-ST segment elevation acute coronary syndrome (NSTE-ACS), the diagnostic efficacy of traditional ECG is not sensitive and specific. Plane QRS-T angle (PQRS-Ta) can be used as a supplement to the current diagnostic criteria of ECG.
Methods: The patients with recurrent chest pain in our hospital were analyzed retrospectively, and the plane QRS-T angle of the patients was calculated. The main results were as follows: (1) the clinical indexes of the two groups were analyzed according to the angle of QRS-T. (2) all patients were divided into three groups according to the final diagnosis. The diagnostic efficacy of QRS-T angle combined with standard ECG diagnostic criteria was analyzed, and the incremental diagnostic value of the new standard relative to the original standard was calculated. (3) the patients were scored by Gensini, and the differences of plane QRS-T angle among patients with different scores were compared. (4) the frequency of MACE was recorded, and the prognostic effect of QRS-T angle on the study population was analyzed.
Results: After analyzing the data, there was a difference in the value of plane QRS-T angle between NSTE-ACS population and non-ACS population (p < 0.001). It was found that every 1 °increase of plane QRS-T angle increased the risk of NSTE-ACS by 2.5% (χ 2, 27.59, P < 0.001). The diagnostic accuracy of AUC quantified plane QRS-T angle combined with standard ECG in the diagnosis of NSTE-ACS was 0.68 (CI [0.64 ~ 0.70]). Through the analysis of NRI and IDI index, the relative NRI of the new model to the original model is 6.67%, 95% CI is 3.91%, and the CI is 9.42% (P < 0.001). The IDI is 6.30%, the CI is 4.65%, and the CI is 7.95% (P < 0.001). The new model improves the prediction effect by 6%. When the QRS-T angle increased by 1 °, the Gensini score increased by 0.199 points (95% CIRV 0.149) (Fidel60.975 (P < 0.001). Comparing prognosis of the three groups, there was a statistical difference in the overall survival time among the three groups (χ 2 = 19.090 P < 0.001).
Conclusion: Compared with the original standard, the new diagnostic standard can improve the diagnostic efficiency of ECG. QRS-T angle can predict the prognosis of patients with NSTE-ACS. The higher the value of QRS-T angle, the greater the probability of major adverse cardiovascular events (MACE) in patients with non-ST segment elevation acute coronary syndrome.