Risk stratification in pulmonary embolism: lessons from the EMPEROR registry

A great deal has recently been written about the use of biomarkers and echocardiography for risk stratification of patients presenting with pulmonary embolism (PE). Data from the EMPEROR study, presented recently at the annual meeting of the Society for Academic Emergency Medicine, compared biomarkers and clinical scores. The presentation was reported in Hospitalist News:

None of the predictors displayed good sensitivity for predicting adverse events. However, a PESI greater than 100 had outstanding specificity and conferred an 8.7-fold increased likelihood of adverse outcome. The shock index performed second best. The two vital signs proved to be slightly better predictors than the two biomarkers.

PESI is the pulmonary embolism severity index and is explained here. The shock index is the ratio of heart rate to systolic blood pressure. A value of over 1 was an adverse sign in EMPEROR.

In patients with pulmonary embolism, routinely calculate the pulmonary embolism severity index (PESI) and shock index, and strongly consider admission to an ICU for patients with elevated values, Dr. Jeffrey A. Kline advised at the annual meeting of the Society for Academic Emergency Medicine.

Although there has been considerable interest in use of biomarkers, echocardiography and clinical assessment to predict good outcomes and select patients for early discharge that was not evaluated in EMPEROR. However, PESI and the Geneva score were evaluated in a 2007 study published in Chest with this conclusion:

The PESI quantified the prognosis of patients with PE better than the Geneva score. This study demonstrated that PESI can select patients with very low adverse event rates during the initial days of acute PE therapy and assist in selecting patients for treatment in the outpatient setting.