PURPOSE: Multiple risk stratification scoring systems exist to forecast outcomes in patients with acute pulmonary embolism (PE). The comparative validity of these scores has not been assessed. We evaluated the ability of the PE severity index (PESI) and the Prognosis in PE (PREP) score to predict 30-day mortality in acute PE.
METHODS: We retrospectively evaluated consecutive patients diagnosed with PE (October 2007-February 2009). PE was diagnosed using CT chest with PE protocol, ventilation-perfusion scanning, or MRA. The PESI and PREP scores were calculated for all subjects. The PESI consists of 11 clinical variables, while the PREP consists of only 3 clinical variables. Raw PESI scores were segregated into risk class (I-V) and then further dichotomized into low (I-II) vs high (III-V) risk groups. Similarly, the raw PREP scores were divided into low (0-5) vs high (>5) risk groups. The primary endpoint was 30-day mortality. We determined the negative predictive value (NPV) of these scoring tools and computed the area under the receiver operating characteristics (AUROC) curves to compare the ability of these scoring tools.
RESULTS: The cohort consists of 302 subjects (mean age: 59.7 +/- 17.2; male: 44%) and 3.0% died within 30 days. The PESI and the PREP performed similarly. [PESI AUROC: 0.858 (95% CI: 0.773-0.943) vs. 0.719 (95% CI: 0.563-0.875) for PREP]. Segregating these scoring tools into class or risk categories did not significantly affect the discriminatory power of either scoring tool [AUROC: 0.845 (95% CI: 0.756-0.914) for PESI class, 0.684 (95% CI: 0.559-0.810) for PESI high vs low risk groups, and 0.790 (95% CI: 0.679-0.903) for PREP risk groups]. The NPV for death of being classified as low risk by the PESI or PREP were 100% and 99%, respectively.
CONCLUSION: The PREP score performed comparably to the PESI score for identifying PE patients at low risk for short term mortality.
CLINICAL IMPLICATIONS: The simpler PREP score may help clinicians risk stratify and triage those with acute PE.
DISCLOSURE: Chee Chan, No Financial Disclosure Information; No Product/Research Disclosure Information