The impact of saddle embolism on the major adverse event rate of patients with non-high-risk pulmonary embolism

To retrospectively quantify right ventricular dysfunction (RVD) and the pulmonary artery obstruction index at helical computed tomography (CT) on the basis of various criteria proposed in the literature and to assess the predictive value of these CT parameters for mortality within 3 months after the initial diagnosis of pulmonary embolism (PE). Institutional review board approval was obtained, and informed consent was not required for retrospective study. In 120 consecutive patients (55 men, 65 women; mean age +/- standard deviation, 59 years +/- 18) with proved PE, two readers assessed the extent of RVD by quantifying the ratio of the right ventricle to left ventricle short-axis diameters (RV/LV) and the pulmonary artery to ascending aorta diameters, the shape of the interventricular septum, and the extent of obstruction to the pulmonary artery circulation on helical CT images, which were blinded for clinical outcome in consensus reading. Regression analysis was used to correlate these parameters with patient outcome. CT signs of RVD (RV/LV ratio, >1.0) were seen in 69 patients (57.5%). During follow-up, seven patients died of PE. Both the RV/LV ratio and the obstruction index were shown to be significant risk factors for mortality within 3 months (P = .04 and .01, respectively). No such relationship was found for the ratio of the pulmonary artery to ascending aorta diameters (P = .66) or for the shape of the interventricular septum (P = .20). The positive predictive value for PE-related mortality with an RV/LV ratio greater than 1.0 was 10.1% (95% confidence interval [CI]: 2.9%, 17.4%). The negative predictive value for an uneventful outcome with an RV/LV ratio of 1.0 or less was 100% (95% CI: 94.3%, 100%). There was a 11.2-fold increased risk of dying of PE for patients with an obstruction index of 40% or higher (95% CI: 1.3, 93.6). Markers of RVD and pulmonary vascular obstruction, assessed with helical CT at baseline, help predict mortality during follow-up. Copyright RSNA, 2005.

Patients with acute pulmonary embolism (APE) present with a broad spectrum of prognoses. Computed tomographic pulmonary angiography (CTPA) has progressively been established as a first line test in the APE diagnostic algorithm, but estimation of short term prognosis by this method remains to be explored. Eighty two patients admitted with APE were divided into three groups according to their clinical presentation: pulmonary infarction (n = 21), prominent dyspnoea (n = 29), and circulatory failure (n = 32). CTPA studies included assessment of both pulmonary obstruction index and right heart overload. Haemodynamic evaluation was based on systolic aortic blood pressure, heart rate, and systolic pulmonary arterial pressure obtained non-invasively by echocardiography at the time of diagnosis of pulmonary embolism. The mortality rate was 0%, 13.8% and 25% in the three groups, respectively. Neither the pulmonary obstruction index nor the pulmonary artery pressure could predict patient outcome. In contrast, a significant correlation with mortality was found using the systolic blood pressure (p<0.001) and heart rate (p<0.05), as well as from imaging parameters including right to left ventricle minor axis ratio (p<0.005), proximal superior vena cava diameter (p<0.001), azygos vein diameter (p<0.001), and presence of contrast regurgitation into the inferior vena cava (p = 0.001). Analysis from logistic regression aimed at testing for mortality prediction revealed true reclassification of 89% using radiological variables. These results suggest that CTPA quantification of right ventricular strain is an accurate predictor of in-hospital death related to pulmonary embolism.