Computerized tomographic finding of saddle pulmonary embolism is associated with high mortality in cancer patients

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.

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.

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).

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.