Background: Large pulmonary embolism (PE) is associated with high mortality in cancer patients. Several risk stratification methods have been used in PE setting. While computer-assisted tomography (CT) is now the preferred diagnostic modality for PE, its prognostic value is not well established.
Methods: A retrospective study of patients discharged from our centre between 2000 and 2006 with a PE diagnosis identified 52 patients with thrombus in the main pulmonary artery or the right or left branch. Clinical, echocardiographic and CT data were reviewed; vital status was determined 1 month and 1 year after index event. Patients were divided into saddle (defined as main pulmonary artery thrombus) and non-saddle PE. Multivariate logistic regression was applied to predict vital status, with patient age and CT parameters as predictors.
Results: Eighteen out of 52 patients were found to have a saddle PE. No significant difference was found between the group characteristics, although saddle PE patients were more likely to receive thrombolytic therapy (27.8% vs 2.9%, P = 0.02) and have an echocardiogram within 30 days of PE (61.1% vs 29.4%, P = 0.03). Overall mortality at 1 month was 9.6% with no difference between groups. At 1 year, mortality rates in saddle PE were significantly higher (83.3% vs 41.2%, P = 0.004). Presence of saddle PE was associated with an odds ratio of death within 1 year of 7.41 (95% confidence interval: 1.75-31.46, P = 0.007).
Conclusion: The relatively simple distinction of saddle versus non-saddle PE by CT findings may provide a straightforward method for risk stratification, and remains useful up to 1 year after the index event.