Pulmonary Embolism: Current Management

1. Risk Stratification

Hemodynamic Status (First Split)

Validated Scoring Tools

• PESI (Pulmonary Embolism Severity Index): Classes I–II = low risk; considers age, cancer, cardiopulmonary disease, HR, BP, SpO₂
• sPESI (Simplified PESI): Score of 0 = low risk (age ≤80, no cancer, no cardiopulmonary disease, HR <110, SBP ≥100, SpO₂ ≥95%)
• RV/LV ratio on CT >0.9: Indicates RV strain
• Biomarkers: Troponin I/T (myocardial injury), BNP/NT-proBNP (wall stress)

2. Diagnostic Approach

Pretest Probability

• Wells PE score or Geneva score classifies probability as low/intermediate/high
• YEARS algorithm: Age-adjusted D-dimer thresholds reduce unnecessary CT

D-Dimer

• Only useful to exclude PE in low/intermediate pretest probability
• Age-adjusted cutoff: age × 10 µg/L (in patients >50 years) increases specificity
• Negative D-dimer effectively rules out PE in low-probability patients

Imaging

Suspected High-Risk PE with Shock

• If CTPA not immediately available → bedside echocardiography: RV overload/dysfunction + no other cause = proceed with reperfusion
• Immediate CTPA if patient can be stabilized

3. Anticoagulation (Foundation of All PE Treatment)

Preferred First-Line: Direct Oral Anticoagulants (DOACs)

When VKA (Warfarin) Is Still Used

• Severe renal impairment (CrCl <15–30 mL/min)
• Antiphospholipid antibody syndrome (triple positive)
• Breastfeeding
• Super-morbid obesity (limited DOAC data)
• Warfarin initial dose: 10 mg/day × 2 days (5 mg in elderly/malnourished); must overlap with heparin ≥5 days until INR ≥2.0 (to prevent protein C/S depletion prothrombotic state)

Parenteral Anticoagulants (Bridging or Initial Therapy)

• LMWH (enoxaparin 1 mg/kg SC q12h or 1.5 mg/kg OD): preferred over UFH for most patients; no monitoring, earlier ambulation, home therapy possible
• UFH (80 units/kg bolus → 18 units/kg/hr infusion, aPTT-guided): preferred in massive PE (planned thrombolysis/surgery), severe renal failure, high bleeding risk requiring rapid reversal
• Fondaparinux: alternative to LMWH; once-daily SC

4. Reperfusion Therapy

Indications: High-Risk (Massive) PE

• rtPA (Alteplase): 100 mg IV over 2 hours (preferred)
• Accelerated: 0.6 mg/kg over 15 min (max 50 mg) if cardiac arrest
• Contraindications: prior intracranial hemorrhage, ischemic stroke <3 months, active internal bleeding, recent brain/spine surgery, suspected aortic dissection
• Relative contraindications: age >75, surgery <3 weeks, recent puncture of noncompressible vessel

Intermediate-High Risk PE: Rescue Thrombolysis

• Not routinely given upfront
• Reserved for patients who deteriorate hemodynamically despite anticoagulation
• Decision made through Pulmonary Embolism Response Team (PERT)

Catheter-Directed Therapy (CDT)

• Catheter-directed thrombolysis (CDT): Lower-dose tPA delivered directly into clot via catheter (e.g., 1–2 mg/hr per catheter × 12–24 hrs)
• Ultrasound-accelerated thrombolysis (EKOS): Ultrasound energy + local tPA — reduces tPA dose/duration, may reduce bleeding
• Mechanical thrombectomy (AngioVac, FlowTriever): Aspiration/fragmentation without thrombolytics — useful when thrombolytics contraindicated
• Indications: Intermediate-high risk PE failing anticoagulation; high-risk PE with thrombolysis contraindication

Surgical Embolectomy

• For massive PE with absolute contraindications to thrombolysis
• Also for clot-in-transit with PFO
• Mortality in experienced centers: ~10–20% in selected patients

5. Supportive Care

• Oxygen: Target SpO₂ ≥90%; mechanical ventilation if needed (use low tidal volumes — RV afterload sensitive)
• Vasopressors: Norepinephrine preferred for RV failure/hypotension; avoid aggressive fluid loading (can worsen RV dilation and cause LV underfilling)
• Dobutamine: Consider for low cardiac output with normal/elevated filling pressures
• ECMO: Rescue for refractory shock as bridge to definitive therapy

6. Duration of Anticoagulation

• Rivaroxaban 10 mg OD
• Apixaban 2.5 mg BID

7. Low-Risk PE: Early Discharge / Outpatient Treatment

• PESI Class I–II or sPESI = 0 with no other concerns: candidates for early discharge (<24 hours) or full outpatient management
• Requires: anticipated compliance, adequate family/social support, no concerns about bleeding
• DOAC (apixaban or rivaroxaban) initiated in ED — no hospitalization needed

8. Special Situations

PE in Pregnancy

• LMWH is treatment of choice throughout pregnancy (DOACs and warfarin contraindicated)
• Fondaparinux: second-line if LMWH not tolerated
• Thrombolysis only for life-threatening massive PE
• IVC filter only if anticoagulation absolutely contraindicated

Cancer-Associated PE

• DOACs (edoxaban, rivaroxaban) are now preferred over LMWH for most patients
• Exception: GI/GU malignancies with high bleeding risk → LMWH preferred
• Anticoagulation continued as long as cancer is active

Subsegmental PE (SSPE)

• Isolated SSPE without DVT on ultrasound + low-risk features: anticoagulation vs. surveillance is debated
• Anticoagulation generally recommended if DVT present or high cardiorespiratory reserve is lacking

Chronic Thromboembolic Pulmonary Hypertension (CTEPH)

• Occurs in ~3–4% after acute PE
• Screen at 3–6 months post-PE if persistent dyspnea
• Treatment: Pulmonary thromboendarterectomy (PTE) — potentially curative for operable disease
• Inoperable CTEPH: Riociguat (sGC stimulator) — approved therapy
• Balloon pulmonary angioplasty (BPA): emerging intervention for distal inoperable disease

9. IVC Filter

• Not recommended as routine adjunct to anticoagulation
• Indications: Acute PE with absolute contraindication to anticoagulation; recurrent PE despite therapeutic anticoagulation
• Retrievable filters preferred — retrieve once anticoagulation can be safely resumed
• Prophylactic filters do NOT reduce mortality and increase DVT risk

Summary Algorithm

Suspected PE
    │
    ▼
Hemodynamically UNSTABLE (SBP <90)?
    ├── YES → Echo/CTPA → HIGH-RISK PE
    │           ├── Systemic thrombolysis (alteplase 100mg/2hr)
    │           ├── If thrombolysis contraindicated → Surgical embolectomy / Catheter thrombectomy
    │           └── UFH anticoagulation throughout
    │
    └── NO → Assess pretest probability (Wells/YEARS)
                ├── Low probability → D-dimer
                │       ├── Negative → PE excluded
                │       └── Positive → CTPA
                └── Moderate/High → CTPA
                        │
                        ▼
                    CTPA confirms PE
                        │
                        ▼
                Risk stratify: RV dysfunction? Troponin? PESI?
                    ├── Intermediate-high → DOAC + close monitoring ± PERT
                    │       └── Deterioration → Rescue thrombolysis / CDT
                    ├── Intermediate-low → DOAC anticoagulation, ward admission
                    └── Low-risk → DOAC, early discharge / outpatient

Important note: There are no published "AHA 2026" PE guidelines as of the current date. The landmark society guidelines are the 2019 ESC/ERS Guidelines and the 2020 ASH VTE Guidelines. The AHA's most recent PE-specific scientific statement is from 2011. The management framework above reflects the current standard of care based on the latest evidence incorporated into 2024–2025 textbooks.