PATHOS-Lactate score: A novel prognostic tool for predicting in-hospital mortality in acute pulmonary embolism

Early mortality risk assessment is essential in patients with acute pulmonary embolism (PE).

To evaluate the prognostic performance of the PATHOS-Lactate score, a novel composite index combining the PATHOS score and serum lactate level, in assessing in-hospital mortality among patients with PE.

We retrospectively analyzed adult patients (aged ≥18 years) who were diagnosed with PE by computed tomography pulmonary angiography (CTPA) in the emergency department (ED) of a tertiary hospital between January 2023 and January 2025. The PATHOS-Lactate score was derived from the logistic regression equation: 0.685 × PATHOS+0.314 × lactate (mmol/L). Patients were categorized according to in-hospital mortality status. Receiver operating characteristic (ROC) curve analysis was used to compare the prognostic accuracy of lactate, simplified Pulmonary Embolism Severity Index (sPESI), PATHOS, and the combined PATHOS-Lactate score.

A total of 203 patients were included, with an overall in-hospital mortality rate of 20.2% (n = 41). The PATHOS-Lactate score demonstrated superior discriminative performance (AUC=0.842, 95% CI:0.785-0.889) compared with sPESI, PATHOS, and lactate alone, with performance remaining robust after internal validation. At the optimal cutoff value of 3.4, the score was associated with 74.1% sensitivity and 84.0% specificity. In multivariable logistic regression, the PATHOS-Lactate score was independently associated with in-hospital mortality (OR:2.90, 95% CI:1.80-4.60; p < 0.001).

The PATHOS-Lactate score, derived from simple and widely available parameters, was associated with higher prognostic accuracy compared with existing models and may represent a practical tool for early mortality risk assessment in patients with PE.