Risk stratification of patients with acute symptomatic pulmonary embolism.

Patients with acute symptomatic pulmonary embolism (PE) who present with arterial hypotension or shock have a high risk of death (high-risk PE), and treatment guidelines recommend strong consideration of thrombolysis in this setting. For normotensive patients diagnosed with PE, risk stratification should aim to differentiate the group of patients deemed as having a low risk for early complications (all-cause mortality, recurrent venous thromboembolism, and major bleeding) (low-risk PE) from the group of patients at higher risk for PE-related complications (intermediate-high risk PE), so low-risk patients could undergo consideration of early outpatient treatment of PE and intermediate-high risk patients would undergo close observation and consideration of thrombolysis. Clinicians should also use risk stratification and eligibility criteria to identify a third group of patients that should not undergo escalated or home therapy (intermediate-low risk PE). Such patients should initiate standard therapy of PE while in the hospital. Clinical models [e.g., Pulmonary Embolism Severity Index (PESI), simplified PESI (sPESI)] may accurately identify those at low risk of dying shortly after the diagnosis of PE. For identification of intermediate-high risk patients with acute PE, studies have validated predictive models that use a combination of clinical, laboratory and imaging variables.