Risk stratification of acute pulmonary embolism.

Acute pulmonary embolism (PE) is a potentially life-threatening condition, with an overall 3-month mortality rate of 15% and with right ventricular failure as the most common cause of early death. Risk stratification facilitates identification of high-risk patients and may be helpful in guiding the initial and long-term management. In patients with massive PE and hemodynamic instability, rapid risk assessment is paramount and bedside echocardiography and multislice chest computed tomography (CT) are useful for identifying patients who may benefit from thrombolysis or embolectomy. Cardiac biomarkers, including troponin and the natriuretic peptides, are sensitive markers of right ventricular function. Low levels of troponin, B-type natriuretic peptide (BNP), and NT-terminal proBNP are all highly sensitive assays for identifying patients with an uneventful clinical course. Multislice chest CT is not only useful to diagnose or exclude PE; it also is useful for risk assessment. A right-to-left ventricular dimension ratio > 0.9 on the reconstructed CT four-chamber view identifies patients at increased risk of early death. This article focuses on risk stratification tools, including the clinical examination, electrocardiography, echocardiography, cardiac biomarkers, and chest CT.