Historically, patients diagnosed with pulmonary embolism (PE) initially have been managed as inpatients. This practice stemmed from two primary issues: a reported mortality of 18 percent following PE and the need to titrate anticoagulation to therapeutic levels. However, more recent studies report that PE-related mortality is actually only around 3 percent, albeit still a high figure.¹ Additionally, direct oral anticoagulants (DOACs) such as rivaroxaban and apixaban do not require injections or coagulation testing to monitor for therapeutic levels. As a result, many professional society guidelines, including those from ACEP and the American College of Chest Physicians, now recommend that select patients with low-risk PE can be managed as outpatients.^2,3

Low-risk patients are typically classified as those with no hemodynamic instability, no significant cardiopulmonary comorbidities, and no evidence of significant myocardial strain or acute damage. Based on this, it is estimated that 30 to 50 percent of patients with acute PE diagnoses may be eligible for outpatient management.^2,4 Are you discharging 30 to 50 percent of your acute PEs? Doing so has advantages. Outpatient management is associated with lower costs—the median hospital cost among patients discharged from U.S. emergency departments with acute PEs between 2016 and 2018 was $986 compared to $6,130 for those admitted to the hospital.⁵ Other benefits of outpatient management include reduced risk of hospital-acquired conditions and reduced hospital capacity strain.

Outpatient Management of Patients with Low-Risk PE Is Safe

Randomized trials and several observational studies demonstrate that patients with low-risk PE can be managed safely as outpatients.^4,6–8 A systematic review of the outpatient management of PE found that both all-cause and PE-related mortality at 30 days was less than 1 percent among high-quality studies.⁸

Who Is Eligible for Outpatient Management?

Multiple protocols for the outpatient management of PE exist and typically integrate risk-stratification scores as well as clinical and social factors. Commonly used risk-stratification scores for outpatient management include the PE Severity Index (PESI), the Simplified PESI (sPESI), and the Hestia criteria (see Tables 1–3). The PESI and sPESI include vital signs and comorbidities that predict mortality following the diagnosis of PE. Those who have a PESI falling within Class I or II or an sPESI of 0 are potential candidates for outpatient management. In addition to clinical criteria, the Hestia criteria also incorporate medical or social reasons for admission. Validation studies found each of these scores can safely identify low-risk patients but may classify nonoverlapping proportions of patients. Importantly, in addition to having a low-risk PE, patients must lack other conditions requiring hospitalization, lack contra­indications to anticoagulation, and be able to obtain medications promptly and attend a follow-up appointment.

Table 1: Pulmonary Embolism Severity Index

Scoring
≤65: Class I, very low risk
66–85: Class II, low risk
86–105: Class III, intermediate risk
106–125: Class IV, high risk
>125: Class V, very high risk

Table 2: Simplified Pulmonary Embolism Severity Index

Scoring
0:.Low risk
≥1: High risk

Table 3: Hestia Criteria

Scoring
0: 0: Low risk
≥1: High risk

Many protocols also incorporate cardiac biomarkers such as troponin and brain natriuretic peptide (BNP) levels, although the cutoff value for BNP is not consistent (<600 pg/mL has been suggested).⁹ The value of using CT or ultrasound evidence of right ventricular (RV) heart strain in the disposition decision is less clear. Some studies suggest that CT may overestimate RV strain, particularly if using an RV/LV ratio of 0.9 rather than 1.0.^9–12