What is the treatment approach for pulmonary embolism (PE) based on the Pulmonary Embolism Severity Index (PESI) guideline?

Management of Pulmonary Embolism Based on PESI Guidelines

Patients with confirmed PE should be risk-stratified using the PESI or simplified PESI (sPESI) scores, with low-risk patients (PESI class I/II or sPESI=0) eligible for outpatient management when additional exclusion criteria are met. 1

Risk Stratification Using PESI/sPESI

• The Pulmonary Embolism Severity Index (PESI) classifies patients into five risk classes (I-V) based on 30-day mortality risk, with classes I and II representing low risk (≤3.6% mortality) 1, 2
• The simplified PESI (sPESI) consists of six variables with binary scoring (0 or 1 point for each), where a score of zero classifies patients as low risk (1.0-1.1% 30-day mortality) 1, 3
• PESI has greater discriminatory power than sPESI (area under ROC curve 0.78 vs. 0.72) and classifies a higher proportion of patients as low-risk (40.9% vs. 36.8%) 2

Treatment Algorithm Based on Risk Stratification

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

• Consider for outpatient management if they meet all of the following criteria 3, 1:
  • No hemodynamic instability
  • No severe pain requiring opiates
  • No high bleeding risk
  • No severe renal impairment (CKD stages 4-5, eGFR <30 mL/min) or severe liver disease
  • No social factors preventing safe outpatient care

Intermediate Risk Patients (PESI Class III or sPESI=1)

• Generally require inpatient management initially 3
• Can be considered for early discharge when they meet criteria for low risk (PESI class I/II or sPESI=0) 3
• Those with PESI-48 class III or sPESI-48 score >0 require senior review prior to discharge 3

High Risk Patients (PESI Class IV-V or Hemodynamically Unstable)

• Require inpatient management with consideration of thrombolysis 3, 1
• Present with hypotension and evidence of RV dysfunction 3

Anticoagulation Recommendations

• For outpatient treatment of confirmed PE, use either 3, 1:
  • Low molecular weight heparin (LMWH) and dabigatran
  • LMWH and edoxaban
  • Single-drug regimen (apixaban or rivaroxaban)
• For suspected PE awaiting diagnosis in outpatient setting, apixaban or rivaroxaban may be used 3
• Using a single direct oral anticoagulant (DOAC) in a pathway is preferred to minimize confusion over dosing 3

Additional Assessment Considerations

• Right ventricular (RV) dysfunction assessment on CT or echocardiography is not mandatory for identifying low-risk patients for outpatient management 3
• If RV dilatation is identified, consider measuring cardiac biomarkers (BNP, NT-proBNP, hsTnI or hsTnT); normal values support low-risk classification 3
• The addition of echocardiographic parameters (TAPSE and PASP) to PESI can improve mortality prediction (PESI-Echo score) 4
• Concomitant DVT should be considered an indicator of significant comorbidity in acute PE 3

Implementation Considerations

• Studies show 33.7-49.7% of PE admissions are "low risk" and qualify for outpatient management, suggesting underutilization of risk stratification tools 5
• All pregnant and postpartum women with suspected or confirmed PE require consultant review and discussion with maternity services prior to discharge 3
• Follow-up of PE should be performed by clinicians with special interest in venous thromboembolism 3
• Despite availability of PESI, evidence suggests it may not be widely used in clinical practice, as demonstrated by similar lengths of hospital stay between risk groups 6

Pitfalls and Caveats

• PESI and sPESI may remain elevated due to non-reversible factors (e.g., cancer, age) which should be considered when using clinical judgment 3
• For patients initially admitted with RV dysfunction or elevated biomarkers, consider repeating assessment before discharge 3
• Consider initial assessment of provoking risk factors for the index PE at an early stage, as this will determine anticoagulation duration 3
• Robust systems must be in place for follow-up and monitoring of outpatients 1