Validation of a model for identification of patients at intermediate to high risk for complications associated with acute symptomatic pulmonary embolism

BACKGROUND: For patients with acute symptomatic pulmonary embolism (PE), the Bova score classifies their risk for PE-related complications within 30 days after diagnosis. The original Bova score was derived from 2,874 normotensive patients with acute PE who participated in one of six prospective PE studies. METHODS: We retrospectively assessed the validity of the Bova risk model in normotensive patients with acute PE diagnosed in an academic urban ED. Two clinician investigators used baseline data for the model's four prognostic variables to stratify patients into the three Bova risk stages (I-III) for 30-day PE-related complications. Intraclass correlation coefficient (ICC) and the k statistic were used to assess interrater variability. RESULTS: Th e Bova risk score classified the majority of the cohort of 1,083 patients into the lowest Bova risk stage (stage I, 80%; stage II, 15%; stage III, 5%), The primary end point occurred in 91 of the 1,083 patients (8.4%; 95% CI, 6.7%-10%) during the 30 days after PE diagnosis. Risk stage correlated with the PE-related complication rate (class I, 4.4%; class II, 18%; class III, 42%; ICC, 0.93 [95% CI, 0.92-0.94]; κ statistic, 0.80; P <.001), in-hospital complication rate (class I, 3.7%; class II, 15%; class III, 37%), and 30-day PE-related mortality (class I, 3.1%; class II, 6.8%; class III, 10.5%). CONCLUSIONS: The Bova risk score accurately stratifies normotensive patients with acute PE into stages of increasing risk of PE-related complications that occur within 30 days of PE diagnosis.