Abstract P590: Clinical Significance of Nonspecific T-Wave Abnormalities on Electrocardiogram

Abstract

Background: The electrocardiogram (ECG) is a tool to effectively evaluate for coronary heart disease (CHD). Clinicians seek out major ST/T changes as key indicators of myocardial infarction/ischemia. However, subtle T wave abnormalities which are less than 2 mm in depth are termed “nonspecific” or “borderline” and are often considered incidental. These findings have been previously reported to be associated with both CHD and cardiovascular disease mortality. CHD manifests in many different populations; therefore, it is vital to study the association of nonspecific T wave changes and ischemic heart disease in different genders, age groups, and ethnicities to determine if there is clinical significance of this finding. If so, this may serve as a prognostic factor for cardiac disease which may warrant the need for earlier CHD evaluation by stress test, echocardiogram, or cardiac catheterization. Prior observation from this group does not show any race or gender difference in EF in the general population. Methods: ECGs performed at a university-affiliated hospital from January 2015 to March 2015 were downloaded from ECG Intellispace software and analyzed for the presence of “nonspecific T” and “borderline T” abnormalities in order to determine their clinical significance. Patient encounters corresponding to these ECG findings were analyzed for age, gender, BMI, hypertension (HTN), diabetes, and history of smoking, in addition to documentation of available stress testing, cardiac catheterization (cath), and echocardiographic ejection fraction (EF) results. Ejection fraction analysis was compared amongst subgroups of patients divided by age, gender, and race by calculating the average EF and standard deviation along with performing student-t test and ANOVA. Results: Out of 2825 ECGs analyzed, there were 582 encounters (20.6%) with nonspecific T wave abnormalities, out of which 247 had documented EFs, and only 47 documented stress tests and 58 documented caths. Average age and BMI is 52.2 ± 16.1 years and 30.6 ± 9.12 kg/m2, respectively. The prevalence of HTN, diabetes, and smoking was 63.4%, 26.7%, and 43.8%, respectively. EFs (%) among WMs, WFs, AAMs, and AAFs were 54.7 ± 12.7, 57.1 ± 14.2, 51.6 ± 16.3, 58.2 ± 12.6, respectively (P = 0.03 by ANOVA, mostly contributed by the low EF in AAM). The stress test and cath numbers were too small to conduct a meaningful statistical analysis. Conclusion: Significantly lower EF in AAM was found compared with other gender and race subgroups. The reason for this finding is not clear; however, ischemia cannot be excluded since analysis for correlation between ECG finding of nonspecific T wave abnormalities and CHD was limited by the small number of stress tests and caths available. This finding was not previously reported in the literature, but is of paramount importance in considering EF evaluation in AAM with nonspecific T wave abnormalities by ECG.