Comparing the pulmonary embolism severity index and the prognosis in pulmonary embolism scores as risk stratification tools

Abstract

Multiple risk stratification scoring systems exist to forecast outcomes in patients with acute pulmonary embolism (PE). We evaluated the comparative validity of the PE severity index (PESI) and the prognosis in pulmonary embolism (PREP) scores to predict mortality in acute PE. Retrospective observational cohort study. Washington Hospital Center, Washington, DC. Consecutive adults (aged >18 years) diagnosed with acute PE. The PESI and PREP scores were calculated. Raw PESI scores were segregated into risk class (I-V) and then dichotomized into low (I-II) versus high (III-V) risk groups; the raw PREP scores were divided into low (0-7) versus high (>7) risk groups. The primary endpoint was 30-day and 90-day mortality. We determined the negative predictive value and computed the area under the receiver operating characteristics (AUROC) curves to compare the ability of these scoring tools. The cohort consisted of 302 subjects. Thirty-day mortality was 3.0%, and 4.0% died within 90 days. The PESI and the PREP performed similarly (PESI AUROC: 0.858 [95% confidence interval (CI), 0.773-0.943] vs 0.719 [95% CI, 0.563-0.875] for PREP). Segregating these scores into risk categories did not affect their discriminatory power (AUROC: 0.684 [95% CI, 0.559-0.810] for PESI and 0.790 [95% CI, 0.679-0.903] for PREP). The negative predictive value for death of being classified as low risk by the PESI or PREP was 100% and 99%, respectively. The PREP score performed comparably to the PESI score for identifying PE patients at low risk for short-term and intermediate-term mortality.