Prognostic Significance Of QRS Distortion And Frontal QRS-T Angle In Patients With ST-elevation Myocardial Infarction

Objective: This study is aimed to investigate the prognostic value ofQRS distortion(Grade 3 ischemia,G3I)and frontal QRS-T angle(frontal QRS-T angle,fQRS-T angle)for patients with acute ST-segment elevation myocardial infarction(STEMI),identify the cutoff value of fQRS-T angle to predict the probability of 12-month and 42-month postdischarge death,compare the impact of these two indicators on the predicted value when applied individually and in combination.Methods:1.All data were collected restrospectively for patients admitted to the First Hospital of Jilin University cardiovascular units,from January 1,2017 to June 30,2017,with diagnosis of ST-segment elevation myocardial infarction(STEMI),who met inclusion criteria(n=592).Participants were followed up for a period of 42months(follow-up cutoff date: December 31,2020).Clinical data of these 592 patients were collected and analyzed,including general information,disease data,coronary angiography data and follow-up data.2.Investigate the prognostic value of G3 I to STEMI patients: patients were divided into two groups according to the presence or absence of G3 I at admission: group A1(presence,n=203)and group A2(absence,n=389).Pairs of patients with or without G3 I were derived using 1:1 greedy nearest neighbor matching within PS score of 0.2.This strategy resulted in 203 matched pairs in each group.Data of the two groups was analyzed and compared,which include general information,laboratory results,electrocardiogram(ECG)reports,cardiac color Doppler echocardiography results,severity of coronary disease and prognosis data,and try to identify factors that affect G3 I.3.Investigate the prognostic value of fQRS-T angle to STEMI patients: all patients were classified into different groups based on death or not in hospital,in 12 months and in 42 months follow-up: group D1(dead in hospital,n=12)and group D0(alive in hospital,n=580),group E1(died within 12 months,n=70),group E0(alive within 12 months,n=522),group F1(died within 42 months,n=136)and group F0(alive within 42 months,n=456).Separate analyses were performed in each two groups of the same time,in order to determine whether fQRS-T angle is statistically different.Receiver operator characteristic(ROC)curve analysis was used to determine the cutoff value of fQRS-T angle for predicting all-cause death within 12 months and within 42 months.4.Binary logistic regression analysis was performed to determine the independent risk factors of all-cause death in STEMI patients within 12 months and within 42 months,and determine whether G3 I and fQRST angle are independent risk factors for all-cause death or not.5.ROC curve was used to compare the sensitivity and specificity of applying G3 I or fQRS-T angle alone,or applying the combination of these two,to predict all-cause mortality in STEMI patients within 12 months and within 42 months.Results and conclusions: 1.STEMI patients with G3 I had a poor Killip class,higher mortality within 12 months and 42 months,differences were statistically significant(p<0.05).2.Several factors could affect the G3 I,such as Killip class,coronary recanalization time,and cardiac troponin I(c Tn I)at admission.Among them,the positive correlation with coronary recanalization time is the closest.3.G3 I is an independent risk factor for all-cause death in STEMI patients within 12 months and within 42 months.4.Increased fQRS-T angle is an independent risk factor for all-cause death within 12 months and within 42 months in STEMI patients.The critical values for predicting death within 12 months and within 42 months are 66.5° and 90.5°.5.The increase of fQRS-T angle in STEMI patients is positively correlated with age,hypertension,previous myocardial infarction or coronary artery bypass,brain natriuretic peptide(BNP),D-dimer,left ventricular end-diastolic diameter(LVEDD),and left atrial diameter(LAD);and is negatively correlation with high-density lipoprotein cholesterol(HDL-C),hemoglobin(HGB)and left ventricular ejection fraction(LVEF).6.When G3 I and fQRS-T angle are combined used to predict the mortality of STEMI patients within 12 months and 42 months,the specificity is significantly improved,while the sensitivity is decreased.