What are the indications for endovascular treatment in adults, particularly older adults with underlying cardiovascular disease, presenting with acute pulmonary embolism and hemodynamic instability or right ventricular dysfunction?

Indications for Endovascular Treatment of Acute Pulmonary Embolism

Endovascular treatment is indicated for high-risk pulmonary embolism patients with hemodynamic instability (systolic blood pressure <90 mmHg or requiring vasopressor support) who have contraindications to systemic thrombolysis, have failed systemic thrombolysis, or are in shock likely to cause death before systemic thrombolysis can take effect. 1

Primary Risk Stratification Framework

The decision to pursue endovascular intervention depends critically on PE severity classification:

High-Risk (Massive) PE

• Hemodynamic instability: Systolic blood pressure <90 mmHg for ≥15 minutes, drop of ≥40 mmHg from baseline, or requiring vasopressor support 1
• Mortality risk: Approximately 30-50% at 90 days without reperfusion therapy 1, 2
• Primary recommendation: Systemic thrombolysis is first-line treatment 1, 2
• Endovascular indication: When systemic thrombolysis is contraindicated, has failed, or shock will cause death within hours before systemic therapy can work 1

Intermediate-Risk (Submassive) PE

• Definition: Right ventricular dysfunction on echocardiography (RV/LV ratio >0.9) or elevated cardiac biomarkers (troponin, BNP) WITHOUT hypotension 1
• Mortality risk: Moderate, approximately 10% will decompensate hemodynamically 3
• Primary recommendation: Anticoagulation alone is preferred over routine thrombolysis 1
• Endovascular consideration: Generally NOT indicated for routine use 1

Low-Risk PE

• No RV dysfunction or biomarker elevation 1
• Mortality risk: Approximately 1% at 1 month 1
• Treatment: Anticoagulation alone 1
• Endovascular role: No indication 1

Specific Endovascular Indications

Catheter-Directed Thrombolysis (CDT)

Use catheter-directed approaches only in highly selected circumstances:

• High bleeding risk patients with hemodynamic instability where systemic thrombolysis poses unacceptable hemorrhagic risk 1
• Failed systemic thrombolysis with persistent hemodynamic compromise 1
• Impending death from shock where systemic thrombolysis cannot act quickly enough (within hours) 1
• Contraindications to systemic thrombolysis in high-risk PE patients 1

Important caveat: The 2021 CHEST guidelines note this is a weak recommendation based on low-certainty evidence, as no randomized trials have compared contemporary CDT with systemic thrombolytic therapy 1. When systemic thrombolysis is feasible, it should be preferred over CDT via peripheral vein 1.

Mechanical Thrombectomy

Consider percutaneous mechanical thrombectomy in the same clinical scenarios as CDT:

• High-risk PE with contraindications to thrombolysis 1
• Failed systemic thrombolysis with ongoing hemodynamic instability 1
• Cardiac arrest or near-arrest from massive PE 1

Critical requirement: Appropriate expertise and resources must be available 1. Transfer to centers equipped for thrombectomy is recommended for patients with severe symptoms, hemodynamic instability, or cardiac arrest 1.

Clinical Decision Algorithm for Older Adults with Cardiovascular Disease

Step 1: Assess Hemodynamic Status

• If systolic BP <90 mmHg or requiring vasopressors: High-risk PE → Proceed to Step 2 1
• If normotensive with RV dysfunction/elevated biomarkers: Intermediate-risk PE → Anticoagulation alone, close monitoring for deterioration 1
• If normotensive without RV dysfunction: Low-risk PE → Anticoagulation alone 1

Step 2: Evaluate for Systemic Thrombolysis (High-Risk PE)

Assess contraindications: 2, 4

• Absolute: Recent hemorrhage, recent stroke, active GI bleeding
• Relative: Peptic ulcer disease, surgery within 7 days, prolonged CPR, pregnancy (within 6 hours of delivery)

If no contraindications: Administer alteplase 100 mg IV over 2 hours via peripheral vein 1, 2, 4

If contraindications present OR high bleeding risk: Proceed to Step 3

Step 3: Consider Endovascular Intervention

Indications for catheter-based therapy in high-risk PE: 1

• Contraindication to systemic thrombolysis
• Failed systemic thrombolysis (persistent hemodynamic instability)
• Shock likely to cause death within hours (before systemic therapy effective)

Transfer immediately to center with interventional capabilities and cardiac surgery backup 1

Step 4: Monitor Intermediate-Risk PE for Deterioration

Close monitoring parameters indicating need for escalation: 1, 4

• Decrease in systolic BP
• Increase in heart rate
• Worsening gas exchange (SaO₂ <95%)
• Signs of inadequate perfusion
• Worsening RV function on repeat echo
• Rising cardiac biomarkers

If deterioration occurs: Consider thrombolysis if bleeding risk acceptable 1, 4

Common Pitfalls to Avoid

Overuse of endovascular therapy in intermediate-risk PE: The ASH guidelines provide a conditional recommendation AGAINST routine thrombolysis in submassive PE 1. Endovascular therapy should not be routinely used in this population despite RV dysfunction, as anticoagulation alone is preferred 1.

Underuse of systemic thrombolysis in high-risk PE: Real-world data shows only 29.7% of hemodynamically unstable patients receive thrombolysis despite guideline recommendations 5. Systemic thrombolysis reduces mortality (RR 0.61) in high-risk PE and should be the first-line reperfusion strategy when not contraindicated 1.

Choosing CDT over systemic thrombolysis without clear indication: When both are feasible, systemic thrombolysis via peripheral vein is preferred over catheter-directed approaches 1. CDT should be reserved for specific scenarios where systemic therapy is contraindicated or has failed.

Delayed treatment in high-risk PE: Early administration of systemic thrombolysis is associated with reduced short-term mortality and lower bleeding rates 6. The therapeutic window matters—do not delay reperfusion therapy in hemodynamically unstable patients.

Failure to involve multidisciplinary teams: High-risk and high-intermediate-risk PE patients benefit from multidisciplinary PE response teams (PERT) combining cardiology, critical care, interventional radiology, and cardiac surgery expertise to determine optimal intervention 1, 3. However, note that PERT implementation has not yet demonstrated mortality improvement in studies 1.