Introduction: The Pulmonary Embolism Severity Index (PESI) is a well-validated tool for prediction of 30-day mortality in acute pulmonary embolism (PE) patients, but it still requires additional improvement in early mortality risk estimation. Simple, cost-effective and widely accessible markers are needed as reliable supplementary tools to PESI score in any clinical or organizational setting. (1, 2) The aim of this study was to compare the predictive value of well-known and validated PESI score and the ratio of red blood cell distribution width (RDW) to albumin concentration (RAR) for 30-day mortality in patients diagnosed with PE, along with evaluating RDW and albumin as individual biomarkers.

Patients and Methods: A double-center analysis included 712 patients hospitalized for pulmonary embolism from January 2013 to September 2023.

Results: Of the hospitalized patients, 56,5% were women. The median age was 73 years (interquartile range IQR:61-80). The median PESI score was 102 points (IQR:70-135). A total of 20,1% of patients had malignant disease in their medical history. The median RDW was 14.2% (IQR 13.3-15.6), albumin level was 37 g/L (IQR: 32-40), while for RAR was 3.98 dl/g (IQR: 3.42-4.89). The 30-day mortality was 12.2%. Patients were categorized into two groups: a low RAR group and high RAR group with median RAR of 3.988 g/dL. Those with higher RAR were significantly older, more often female and had a lower BMI (P<0.05 for all analyses). In a multivariate logistic regression model that analyzed RDW >14.6%, albumin <=34 g/L, RAR >4.41 dl/g and PESI >121, RDW >14.6 (OR 2.71, 95% CI (1.34-5.47), P=0.005), albumin <=34 g/L (OR 2.9, 95% CI (1.29-6.51), P=0.009) and PESI >121 points (OR 6.9, 95% CI (3.72-12.79), <0.001) were recognized as mutually independent predictors of 30-day mortality, while RAR did not statistically significantly contribute to prognosis in the context of other analyzed parameters.

Conclusion: In patients with pulmonary embolism, RDW and albumin can provide additional prognostic information compared to the PESI score. However, their ratio (RAR) does not contribute additionally to the prognosis of 30-day mortality when RDW and albumin are taken into account as individual parameters.