What is the recommended treatment for pulmonary embolism?

Treatment of Pulmonary Embolism

Immediate Anticoagulation Based on Risk Stratification

For most patients with confirmed pulmonary embolism, initiate immediate anticoagulation with a direct oral anticoagulant (DOAC)—specifically rivaroxaban or apixaban as single-drug regimens—which are now preferred over warfarin and low-molecular-weight heparin combinations. 1

Treatment intensity depends entirely on hemodynamic status and right ventricular function:

High-Risk PE (Hemodynamically Unstable)

Administer unfractionated heparin (UFH) intravenously immediately without waiting for diagnostic confirmation: 1, 2

• Initial bolus: 80 U/kg IV 3, 1
• Continuous infusion: 18 U/kg/h 3, 1
• Adjust based on aPTT to maintain 1.5-2.3 times control (46-70 seconds) using a nomogram 3

Systemic thrombolytic therapy is mandatory for all high-risk PE unless absolute contraindications exist (Class I, Level B recommendation): 1, 2, 4

• Alteplase 100 mg over 90 minutes for stable patients 2
• Alteplase 50 mg IV bolus for cardiac arrest 2

Surgical pulmonary embolectomy is recommended when thrombolysis is contraindicated or has failed (Class I, Level C): 3, 2, 4

• Performed via median sternotomy with normothermic cardiopulmonary bypass 3
• Terminate procedure once hemodynamics improve, regardless of angiographic result 3

Intermediate-Risk PE (Hemodynamically Stable with RV Dysfunction)

Initiate anticoagulation with a DOAC immediately: 1, 2

• Preferred agents: Rivaroxaban or apixaban as single-drug regimens 1, 4
• Alternative DOACs: Dabigatran or edoxaban (Class I, Level A) 4

Do not use routine thrombolysis, but maintain readiness for rescue thrombolytic therapy if hemodynamic deterioration occurs (Class I, Level B): 2

Low-Risk PE (Hemodynamically Stable without RV Dysfunction)

Initiate DOAC anticoagulation without delay: 1, 2, 4

• First-line: Rivaroxaban or apixaban 1, 4
• Consider early discharge and home treatment for carefully selected patients (Class IIa, Level A) 2

Anticoagulation Selection Algorithm

First-Line: Direct Oral Anticoagulants (DOACs)

DOACs are preferred over vitamin K antagonists for all eligible patients (Class I, Level A): 1, 4

• Rivaroxaban: Single-drug regimen without need for parenteral overlap 1
• Apixaban: Single-drug regimen without need for parenteral overlap 1
• Dabigatran or edoxaban: Require initial parenteral anticoagulation 4

Second-Line: When DOACs Are Contraindicated

Use LMWH or fondaparinux followed by warfarin when DOACs cannot be used: 1

• LMWH options: Enoxaparin, dalteparin, tinzaparin 1
• Fondaparinux: Weight-adjusted dosing (5 mg for <50 kg, 7.5 mg for 50-100 kg, 10 mg for >100 kg) subcutaneously once daily 5
• Overlap with warfarin until INR reaches 2.5 for 2 consecutive days 1, 4

Absolute contraindications to DOACs include: 4

• Severe renal impairment (creatinine clearance <30 mL/min)
• Pregnancy or lactation
• Antiphospholipid antibody syndrome

Duration of Anticoagulation

All patients require therapeutic anticoagulation for at least 3 months: 4

Discontinue anticoagulation after 3 months for: 1, 4

• First PE secondary to major transient/reversible risk factor (provoked PE)

Continue anticoagulation indefinitely for: 1, 4

• Unprovoked PE
• Recurrent venous thromboembolism
• Antiphospholipid antibody syndrome (must use vitamin K antagonist, not DOAC)

Special Populations

Cancer-Associated PE

LMWH is the preferred initial and long-term treatment for cancer patients: 1, 4

• Dalteparin is an established option 1
• Apixaban is an effective alternative 1

Pregnancy

Use therapeutic fixed doses of LMWH based on early pregnancy weight: 1, 4

• All pregnant women with suspected or confirmed PE require consultant review and discussion with maternity services prior to discharge 1

Critical Pitfalls to Avoid

Never delay anticoagulation while awaiting diagnostic confirmation in patients with high or intermediate clinical probability: 1

Never stop parenteral anticoagulation before achieving therapeutic INR for 2 consecutive days when using warfarin: 1

Avoid routine use of inferior vena cava (IVC) filters (Class III, Level A): 2

• Only consider for absolute contraindications to anticoagulation or recurrent PE despite therapeutic anticoagulation 2

Avoid aggressive fluid resuscitation in high-risk PE as it worsens right ventricular function: 1

Never use catheter embolectomy or fragmentation as first-line therapy—reserve only as alternative to surgical treatment when thrombolysis is absolutely contraindicated or has failed: 3