Prognostic assessment is important for the management of patients with acute pulmonary embolism (PE). The Pulmonary Embolism Severity Index (PESI) score has been previously validated in studies, but its widespread use in clinical practice and validity is uncertain.

We sought to validate the PESI as a predictor of short- and intermediate-term mortality.

Consecutive patients admitted at our institution with a confirmed PE between January 2008 and December 2017 were screened. Information on clinical presentation, diagnostic work-up, treatment and mortality during a 30 day and 1-year follow-up was collected. To facilitate analyses, raw PESI score was dichotomized into low risk (I–II) vs. high risk (III–V) groups.

The cohort included 224 subjects (mean age, 58.6±18.2 years; 47% male). Among these patients, 61.3% were at low risk. No significant difference in baseline characteristics between the 2 groups was found. One-year follow-up was available in 97.4% of patients. There was a significant difference in 30-day mortality between the two groups in favour of the low risk group (6.3% vs 24.1%, P<0.001). This difference is maintained at 1 year.

In multivariate analysis, the PESI (class III–IV versus I–II, OR 6.2, 95% CI 2.6–11.2) was an independent predictors of an adverse outcome (death, cardiogenic shock and need for mechanical ventilation).

The discriminatory power of the PESI score to predict long-term mortality, expressed as the area under the ROC curve, was 0.81 (95%CI, 0.62–0.88) at 1 year.

Our data indicate that the PESI score is a reproducible scoring tool in real life to risk stratify patients with acute PE, can be used to predict the prognosis of patients with PE and helps in definitive the optimal management.