Prognostic value of ECG T/R ratio and clinical predictors in septic shock

Septic shock remains a leading cause of mortality in critically ill patients. Electrocardiography (ECG) is a rapid, non-invasive tool, and the T-wave to R-wave amplitude ratio (T/R ratio) has been proposed as a marker of electrolyte disturbances and myocardial stress. Its prognostic value in septic shock, however, is unclear.

To evaluate the association between the admission T/R ratio and short-term mortality in patients with septic shock and to identify independent predictors of mortality.

We conducted a single-center, retrospective observational study of 319 adult patients diagnosed with septic shock who had a 12‑lead ECG on admission. T and R wave amplitudes were manually measured in leads II and V5, and the T/R ratio was calculated. Demographic, clinical, and laboratory data were collected. Multivariable logistic regression was used to identify independent predictors of in-hospital mortality.

Among 319 patients, 214 (67.1%) experienced in-hospital mortality. The T/R ratio was not significantly associated with mortality in univariable or multivariable analyses. Independent predictors of mortality included advanced age (OR, 1.04; 95% CI, 1.01-1.07), elevated white blood cell count (OR, 1.06; 95% CI, 1.00-1.11), hypoalbuminemia (OR, 0.89; 95% CI, 0.84-0.94), hyperkalemia (OR, 1.53; 95% CI, 1.01-2.31), abnormal T wave axis (OR, 1.01; 95% CI, 1.00-1.01), and heart failure (OR, 3.92; 95% CI, 1.35-10.85). The regression model demonstrated good predictive performance (accuracy 75.9%, sensitivity 88.9%, specifically 44.3%, AUC 0.816).

The T/R ratio on admission ECG does not reliably predict short-term mortality in patients with septic shock. Mortality is primarily driven by established clinical and laboratory predictors. ECG-derived indices may provide complementary information but should be interpreted alongside clinical scoring systems and biochemical markers to improve risk stratification and guide management in this high-risk population.