Prognostic Value of QT and QTc Interval Dispersion in Acute Pulmonary Embolism: A Retrospective Single-Center Study

Background: Acute pulmonary embolism (PE) carries substantial mortality risk, yet readily available electrocardiographic markers of ventricular repolarisation heterogeneity remain underutilised in prognostication. This study evaluated the prognostic value of QT dispersion (QTd) and corrected QT dispersion (QTcd) for predicting 30-day mortality in patients with acute PE. Methods: This single-centre, retrospective observational study enrolled 143 consecutive adult patients with CT-angiography-confirmed acute PE presenting to the emergency department between January 2023 and November 2024. PE severity was stratified per 2019 ESC guidelines. Standard 12-lead ECGs obtained at admission, prior to any PE-directed treatment, were analysed by a single blinded observer. The primary outcome was 30-day all-cause mortality. Independent predictors were identified by multivariable logistic regression, and optimal cut-off values were determined by ROC curve analysis. Results: The 30-day mortality rate was 32.2% (n=46/143). The mean age was 71.0 ± 14.3 years; 13.3% of patients were haemodynamically unstable and 20.3% had active malignancy. Non-survivors exhibited significantly greater QTd (60.2 vs 49.3 ms) and QTcd (80.6 vs 63.1 ms) than survivors (both p<0.001). On multivariable analysis, QTcd remained an independent predictor of mortality (OR 1.09 per ms, 95% CI 1.05-1.13; p=0.001), alongside malignancy (OR 5.05), altered mental status (OR 6.10), mean arterial pressure (OR 0.97 per mmHg), and CT-derived left ventricular diameter (OR 0.92 per mm). ROC analysis identified cut-off values of QTd ≥56 ms (AUC 0.812, sensitivity 72%, specificity 83%) and QTcd ≥67 ms (AUC 0.829, sensitivity 87%, specificity 67%, negative predictive value 92%). Conclusion: QTcd is an independent predictor of 30-day mortality in acute PE and provides clinically useful discrimination across all ESC risk strata. The cut-off values identified may complement established risk scores in emergency prognostication; prospective multicentre validation is required before broader clinical adoption.