Relationship between ECG-derived T-wave amplitude and T/R ratio and Syntax score in patients with acute non-st segment elevation myocardial infarction

Objectives and background: Our objective was to determine the diagnostic significance of a low T-wave amplitude (TWA) and T/R ratio, defined as the amplitude ratio between the T waves and the R waves, in patients with acute non-ST elevation myocardial infarction (ANSTEMI). Syntax score (SS) shows the extension of coronary artery disease. Previously, low TWA and T/R ratios were demonstrated to be inversely proportional to the risk of sudden cardiac arrest in different cardiac disease conditions.

Methods: 266 patients were retrospectively included with ANSTEMI between July 2021 and December 2022. SS-1 and SS-2 scores were calculated using the angiographic and clinical data of the patients. The patients were stratified into tertiles based on their median SS-1 scores as lower, moderate, and higher SS-1 tertiles. ECG parameters, including TWAs and T/R ratios in leads II and V5, were measured digitally. TWA and T/R ratios were compared with SSs among the tertiles.

Results: TWA and T/R ratios in leads II and V5 were significantly lower across the increasing SS-1 tertiles (p < 0.001 for TWA in lead II) (p < 0.001 for T/R ratio in lead II) (p = 0.014 for TWA in lead V5) (p = 0.002 for T/R ratio in lead V5).ROC analysis identified T/R ratios in leads II and V5 of 0.254 (AUC: 0.758, p < 0.001) and 0.201 (AUC: 0.635, p < 0.015), respectively.

Conclusion: A low T/R ratio, particularly in lead II due to its greater AUC, better predicts moderate-to-high SS-1 in patients with ANSTEMI.