What are the disposition and treatment recommendations for patients with intermediate to high risk Pulmonary Embolism (PE) based on the Pulmonary Embolism Severity Index (PESI) score?

PESI Score-Based Disposition and Treatment Recommendations

Patients with low-risk PE (PESI Class I-II or sPESI=0) should be considered for early discharge and outpatient treatment with anticoagulation, while intermediate-risk patients (PESI Class III-V) require hospitalization with close monitoring and further risk stratification using RV function assessment and cardiac biomarkers. 1

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

Disposition

• Consider early discharge and outpatient management if the patient has adequate social support, anticipated compliance, and no contraindications to home treatment 1
• Discharge is appropriate when patients meet low-risk criteria and have no exclusion factors such as hemodynamic instability (HR>110, SBP<100), oxygen saturation <90% on room air, active bleeding risk, severe pain requiring opiates, or severe renal/liver disease 1
• Only 36% of PE patients fall into PESI Class I-II, making this a highly selective low-risk group 2

Treatment

• Initiate anticoagulation with either LMWH/fondaparinux followed by dabigatran or edoxaban, OR single-drug regimens with apixaban or rivaroxaban 1, 3
• DOACs are preferred over vitamin K antagonists for eligible patients 1, 3
• If VKA is used, overlap with parenteral anticoagulation until INR reaches 2.0-3.0 (target 2.5) 1, 3

Critical Caveat

• Even with PESI Class I-II, if RV dysfunction is present on imaging or cardiac biomarkers are elevated, reclassify the patient as intermediate-risk and manage accordingly 1
• This discrepancy occurs in approximately 34% of patients with low PESI scores who show RV dysfunction 1

Intermediate-Risk PE (PESI Class III-V)

Initial Disposition

• All intermediate-risk patients require hospitalization for monitoring and further risk stratification 1
• Calculate PESI at presentation, then recalculate at 48 hours (PESI-48) to identify candidates for early discharge 1

Further Risk Stratification Required

Assess RV function using echocardiography or CTPA AND measure cardiac troponin levels to subdivide into intermediate-high versus intermediate-low risk 1

Intermediate-High Risk (RV dysfunction + elevated troponin)

• Close monitoring in a setting that permits early detection of hemodynamic decompensation 1
• Do NOT routinely administer systemic thrombolysis as primary treatment 1, 3
• Administer rescue thrombolytic therapy immediately if hemodynamic deterioration develops (systolic BP drop, rising heart rate, worsening hypoxemia, altered mental status) 1, 3
• Consider surgical embolectomy or catheter-directed therapy as rescue alternatives if thrombolysis is contraindicated or high bleeding risk exists 1

Intermediate-Low Risk (normal RV function OR normal troponin)

• Standard monitoring with anticoagulation 1
• Lower intensity surveillance compared to intermediate-high risk 1

Anticoagulation Strategy

• Initiate LMWH or fondaparinux immediately without waiting for complete diagnostic confirmation if clinical probability is high or intermediate 1, 3
• Transition to DOAC (apixaban, dabigatran, edoxaban, or rivaroxaban) as preferred oral anticoagulant 1, 3
• Reserve unfractionated heparin for patients with severe renal dysfunction (eGFR<30 mL/min) or high bleeding risk 1, 3

Early Discharge Criteria for Initially Intermediate-Risk Patients

• Recalculate PESI at 48 hours: patients reclassified as PESI Class I-II or sPESI=0 can be considered for early discharge 1
• In one study, 27.3% of PESI Class III patients were reclassified as low-risk at 48 hours with 30-day mortality of only 1.2% 1
• If PESI-48 remains Class III or sPESI-48 remains ≥1, senior review is mandatory before discharge as 30-day mortality remains 8.3-12.3% 1
• Consider repeating RV function assessment or biomarkers in patients who had abnormalities at baseline before discharge 1

High-Risk PE (Hemodynamic Instability)

Recognition

• Cardiac arrest, obstructive shock (SBP<90 mmHg requiring vasopressors with end-organ hypoperfusion), or persistent hypotension (SBP<90 mmHg or drop ≥40 mmHg for >15 minutes) 1
• PESI calculation is NOT necessary in hemodynamically unstable patients 1

Treatment

• Immediate systemic thrombolytic therapy is the treatment of choice 1
• Initiate intravenous unfractionated heparin with weight-adjusted bolus immediately 1
• Surgical pulmonary embolectomy if thrombolysis is contraindicated or has failed 1
• Hemodynamic support with norepinephrine as first-line vasopressor; consider dobutamine for low cardiac output with normal BP 4

Common Pitfalls to Avoid

• Do not delay anticoagulation while awaiting complete diagnostic workup in patients with high or intermediate clinical probability 1, 3
• Do not use routine thrombolysis in stable intermediate-risk patients as bleeding risk outweighs benefit 1, 3
• Do not prescribe DOACs to patients with severe renal impairment (CrCl<30), pregnancy, or antiphospholipid syndrome 1, 3
• Do not rely solely on PESI score if RV dysfunction or elevated biomarkers are present - these patients require reclassification to higher risk category 1
• Do not discharge PESI Class III patients without reassessing at 48 hours - those who remain Class III have 8.3% 30-day mortality 1
• Do not use inferior vena cava filters routinely 1
• Do not perform aggressive fluid resuscitation as this worsens RV function by over-distending the right ventricle 4