How is pulmonary embolism managed based on the PESI (Pulmonary Embolism Severity Index) score?

Management of Pulmonary Embolism Based on PESI Score

Patients with confirmed pulmonary embolism and low PESI scores (Class I/II or sPESI=0) should be managed as outpatients with direct oral anticoagulants (apixaban or rivaroxaban), while intermediate and high-risk patients require inpatient management with escalating intensity of monitoring. 1

Risk Stratification Framework

The PESI score stratifies patients into five classes (I-V) based on 30-day mortality risk, with Class I having ≤1.6% mortality and Class II having 3.6% mortality. 2, 1 The simplified PESI (sPESI) uses six binary variables (age >80 years, cancer, chronic cardiopulmonary disease, pulse ≥110 bpm, systolic blood pressure <100 mmHg, arterial oxygen saturation <90%), with a score of 0 identifying low-risk patients who have 30-day mortality of 1.0-1.1%. 2, 1

Key distinction: PESI demonstrates superior discriminatory power compared to the Geneva score, with an area under the ROC curve of 0.76 versus 0.61, and identifies patients with significantly lower 30-day mortality (0.9% vs 5.6%). 2

Treatment Algorithm by Risk Category

Low-Risk Patients (PESI Class I/II or sPESI=0)

Outpatient management is appropriate when mandatory exclusion criteria are absent. 1, 3 These exclusion criteria include:

• Physiologic instability (hemodynamic compromise)
• Active bleeding or recent major bleeding risk
• Severe renal impairment
• Social factors precluding safe discharge 1

Anticoagulation options for outpatients:

• Single-drug regimens: apixaban or rivaroxaban (preferred)
• Dual-drug regimens: LMWH with dabigatran or LMWH with edoxaban 3

Critical implementation requirements:

• Same-day anticoagulation initiation before discharge 1
• Robust pathway for follow-up and monitoring must exist 3
• Review by consultant or senior clinician before discharge 3

Intermediate-Risk Patients (PESI Class III or Higher with sPESI ≥1)

Inpatient management is required with further stratification based on right ventricular dysfunction and cardiac biomarkers. 1 Treatment includes:

• Standard anticoagulation (LMWH, fondaparinux, or NOACs)
• Close monitoring for clinical deterioration
• Consideration of reperfusion therapy if hemodynamic decompensation occurs 1, 4

High-Risk Patients (Hemodynamically Unstable)

Thrombolysis should be reserved exclusively for patients with hemodynamic instability, defined as systolic blood pressure <90 mmHg, requirement for vasopressor support, or persistent hypotension with signs of shock. 4 The American College of Chest Physicians explicitly recommends against routine thrombolysis in hemodynamically stable patients, regardless of PESI score, due to thrombolysis causing 65 more major bleeding events per 1,000 patients and increasing intracranial hemorrhage risk 3-4 fold. 4

Critical Clinical Nuances

Right ventricular dysfunction on imaging alone does not mandate inpatient management or thrombolysis in otherwise stable low-risk PESI patients. 1, 4 However, if RV dilation is present, measure cardiac biomarkers (BNP/troponin) for additional risk stratification. 1

Important prognostic modifiers that increase mortality risk despite low PESI:

• Right heart thrombi (mortality 21% vs 11% without) 1
• Concomitant DVT (OR 1.9 for 30-day mortality) 1
• Active malignancy and heart failure 2

Common Pitfalls to Avoid

Do not rely solely on RV dilation on imaging to exclude patients from outpatient management - the presence of RV dysfunction in an otherwise stable patient with low PESI may warrant inpatient observation and biomarker monitoring, but not thrombolysis. 1, 4

Do not use routine bleeding risk scores beyond the exclusion criteria already outlined for patients deemed low-risk by PESI/sPESI. 1

Do not discharge patients without same-day anticoagulation - this is a mandatory requirement for safe outpatient management. 1

Reserve thrombolysis only for the rare stable patient who demonstrates clinical deterioration despite adequate anticoagulation, characterized by decreasing systolic blood pressure with signs of shock, increasing heart rate with inadequate end-organ perfusion, worsening gas exchange or respiratory failure, progressive RV dysfunction on repeat imaging, or rising cardiac biomarkers. 4

Validation Data

The sPESI was shown to be non-inferior to the full PESI in predicting 30-day mortality, with low incidence of major bleeding and recurrent VTE of ≤1.5% at 30 days in low-risk groups. 2 In a large Japanese registry, patients with sPESI=0 had 30-day mortality of 0.5%, recurrent VTE of 1.3%, and major bleeding of 1.1%, confirming these patients are appropriate candidates for early discharge or home treatment. 5