Acute pulmonary embolism: risk stratification in the emergency department

Pulmonary embolism is a common disease associated with a high mortality rate. Death due to pulmonary embolism occurs more commonly in undiagnosed patients before hospital admission or during the initial in-hospital stay. Thus, mortality could be reduced by prompt diagnosis, early prognostic stratification and more intensive treatment in patients with adverse prognosis. Mortality is particularly high in patients with pulmonary embolism presenting with arterial hypotension or cardiogenic shock. In patients with pulmonary embolism and normal blood pressure, a number of clinical features and objective findings have been associated with a high risk of adverse in-hospital outcome. Advanced age and concomitant cardiopulmonary disease are clinical risk factors for in-hospital mortality. The Bburden of thromboembolism, as assessed by lung scan or spiral CT, and right ventricle overload, as assessed by echocardiography and probably spiral CT, have been claimed to be risk factors for in-hospital mortality. Elevated serum levels of troponins have been shown to be associated with right ventricular overload and adverse in-hospital outcomes in patients with pulmonary embolism. Despite the currently available evidence, no definite prognostic value can be assigned to any of the individual risk factors or cluster of them. Large prospective trials should be carried out to validate individual risk factors or clusters of risk factors able to identify patients with acute pulmonary embolism at high risk for in-hospital mortality. These patients could afford the trade-off of an increased risk of side effects related to a more aggressive treatment, such as thrombolysis or surgical or interventional procedures.