Change in T/QRS ratio can be a supplementary diagnostic tool in predicting coronary artery disease in patients with NSTEMI

Abstract

Background: Changes in the electrocardiographic findings, namely the ratio T sum to QRS sum (T/QRS ratio), between the initial electrocardiogram (ECG) and the baseline ECG have rarely been investigated in patients with non-ST elevation myocardial infarction (NSTEMI). Thus, we aimed to determine whether changes in various parameters on ECG, including T/QRS ratio, can assist in distinguishing between coronary artery disease (CAD) and NSTEMI without CAD with low to moderate risk.

Methods: This retrospective study enrolled 2572 patients who presented ischemic symptoms, who were diagnosed with NSTEMI, and who underwent coronary angiography. Overall, 388 patients had prior ECG and echocardiography data available; 110 patients were included after excluding patients with other cardiac diseases except CAD. The population divided into two groups: a coronary stenosis group (n = 78); normal coronary group (n = 32) were analyzed.

Results: We found that acute dynamic change in the most deviated T/QRS ratio in each region of leads of initial ECG from those of remote/recent ECG was an extremely strong predictor of acute CAD (odds ratio, 110; p < .001) compared to that of initial serum troponin I levels, new-onset regional wall motion abnormalities, and new-onset T inversion or ST depression. T/QRS ratio change > 1.5 or <0.5 times in injured regional leads was a significant predictor of CAD.

Conclusion: Change in the most deviated T/QRS ratio in the regional leads on initial ECG from the T/QRS ratio in the same lead on remote ECG can assist in predicting CAD risk between patients with CAD and patients with no CAD in NSTEMI.

Keywords: Acute coronary syndrome; Coronary angiography; Electrocardiography; Non-ST elevated myocardial infarction.