What are the indications for patent foramen ovale (PFO) closure?

Indications for Patent Foramen Ovale (PFO) Closure

PFO closure is strongly indicated for patients aged 18-60 years with a non-lacunar embolic ischemic stroke or TIA attributed to a PFO after thorough evaluation has excluded alternative etiologies. 1

Patient Selection Criteria

Recommended Candidates

• Age 18-60 years
• Confirmed non-lacunar embolic ischemic stroke or TIA
• PFO determined to be the most likely cause after thorough evaluation excluding alternate etiologies
• High-risk PFO features:
  • Atrial septal aneurysm
  • Large interatrial shunt
  • Substantial right-to-left shunt 1

Risk Stratification

The PASCAL classification system can help identify patients most likely to benefit from PFO closure:

• "Probable" causality: Younger patients without vascular risk factors and high-risk PFO anatomical features (90% decreased relative rate of recurrent stroke with closure) 2
• "Possible" causality: Intermediate risk profile
• "Unlikely" causality: Older patients with vascular risk factors and no high-risk PFO features (no benefit from closure) 2

Contraindications

PFO closure should not be performed in:

• Patients over 60 years of age (unless exceptional circumstances)
• Patients with small deep infarcts (lacunar strokes)
• Cases with identified alternative cause for stroke
• Small PFO without high-risk features
• Patients requiring long-term anticoagulation for another indication 1

Evidence Supporting PFO Closure

Multiple randomized trials demonstrate significant benefit:

• CLOSE trial: Stroke rate 0% in PFO-closure group vs. 6.0% in antiplatelet-only group (NNT = 20 over 5 years)
• REDUCE trial: Ischemic stroke rate 1.4% in closure group vs. 5.4% in antiplatelet-only group (NNT = 28 over 2 years)
• RESPECT trial: Recurrent ischemic stroke rate 3.6% in PFO closure group vs. 5.8% in medical therapy group (NNT = 42 over 5 years) 1

A pooled analysis of 6 trials showed an annualized incidence of stroke of 0.47% with PFO closure vs. 1.09% with medical therapy (adjusted hazard ratio 0.41) 2

Treatment Algorithm

1. For patients open to all options:

   • Weak recommendation for PFO closure plus antiplatelet therapy rather than anticoagulant therapy 3

2. For patients in whom anticoagulation is contraindicated or declined:

   • Strong recommendation for PFO closure plus antiplatelet therapy versus antiplatelet therapy alone 3

3. For patients in whom closure is contraindicated or declined:

   • Weak recommendation for anticoagulant therapy rather than antiplatelet therapy 3

Potential Complications and Risks

• Procedural complications rate: approximately 5.9%
• Atrial fibrillation: occurs in 4.6-6.6% of patients (mostly transient)
• Serious device-related adverse events: 1.4% of patients 1
• The REDUCE trial reported device-related adverse events in 1.4% and atrial fibrillation in 6.6% of patients after PFO closure 4

Special Considerations

Non-Stroke Indications

PFO closure may be considered in selected cases for:

• High-volume divers
• Compressed-air tunnel workers
• High-altitude aviators
• Astronauts
• Those with multiple recurrences of decompression sickness 1, 5

Common Pitfalls to Avoid

1. Recommending PFO closure in patients >60 years despite lack of proven benefit
2. Assuming PFO causality in older patients when it's more likely incidental
3. Neglecting thorough evaluation for other stroke etiologies
4. Overtreatment of incidentally found PFOs without history of cryptogenic stroke
5. Failing to recognize that small PFOs carry lower risk than those with large shunts or associated atrial septal aneurysms 1

Remember that PFO is highly prevalent in the general population (25% of adults), and should not be considered the cause of stroke until a thorough workup has excluded alternative mechanisms 6, 2.