Clinical question: Can the Bova risk model stratify patients with acute PE into stages of increasing risk for 30-day pulmonary embolism (PE)-related complications?
Background: The Bova score is based on four variables assessed at the time of PE diagnosis: heart rate, systolic blood pressure, cardiac troponin, and a marker of right ventricular (RV) dysfunction. In the original study, the Bova risk model was derived from 2,874 normotensive patients with PE. This study performed a retrospective validation of this model on a different cohort of patients.
Study design: Retrospective cohort study.
Setting: Academic urban ED in Madrid, Spain.
Synopsis: Investigators included 1,083 patients with normotensive PE, and the Bova risk score classified 80% into class I, 15% into class II, and 5% into class III—correlating 30-day PE-related complication rates were 4.4%, 18%, and 42%, respectively. When dichotomized into low risk (class I and II) versus intermediate to high risk (class III), the model had a specificity of 97%, a positive predictive value of 42%, and a positive likelihood ratio of 7.9 for predicting 30-day PE-related complications.
The existing risk assessment models, the pulmonary embolism severity index (PESI) and the simplified PESI (sPESI), have been extensively validated but were specifically developed to identity patients with low risk for mortality. The Bova risk model could be used in a stepwise fashion, with the PESI or sPESI model, to further assess intermediate-risk patients.
This model was derived and validated at one single center, so the results may not be generalizable. Additionally, the variables were collected prospectively, but this validation analysis was performed retrospectively.
Bottom line: The Bova risk model accurately stratifies patients with normotensive PE into stages of increasing risk for developing 30-day PE-related complications.
Citation: Fernández C, Bova C, Sanchez O, et al. Validation of a model for identification of patients at intermediate to high risk for complications associated with acute symptomatic pulmonary embolism [published online ahead of print January 29, 2015]. Chest.