What are the complications and management strategies for patients with a patent foramen ovale (PFO)?

Complications from Patent Foramen Ovale

Primary Complication: Paradoxical Embolic Stroke

The most significant complication of PFO is paradoxical embolic stroke, which accounts for approximately 5% of all strokes and 10% of strokes in younger patients, with PFO present in about 50% of patients aged 60 years or younger with cryptogenic stroke. 1

Stroke Risk Stratification

• Annual recurrent stroke rates in PFO patients range from 1.5% to 12%, depending on patient age and anatomical features 2
• The presence of both PFO and atrial septal aneurysm dramatically increases risk, with an odds ratio of 15.59 for ischemic stroke in patients under 55 years 3
• PFO alone carries an odds ratio of 3.1 for ischemic stroke, while atrial septal aneurysm alone has an odds ratio of 6.14 3
• Large right-to-left shunts (>25 microbubbles) and atrial septal aneurysms (>10mm excursion) are the highest-risk anatomical features 3, 4

Non-Cerebral Paradoxical Embolism

• Paradoxical embolism can cause myocardial infarction, renal infarction, and limb ischemia, though these account for only 5-10% of all paradoxical embolic events 2
• These complications are much less studied and primarily reported as case reports, making their true incidence difficult to establish 2
• The YAMIS study found no relationship between right-to-left cardiac shunting and MI in young survivors, suggesting coronary paradoxical embolism is extremely rare 2

Management Strategies by Clinical Scenario

For Patients Under 60 Years with Cryptogenic Stroke

PFO closure plus antiplatelet therapy is strongly recommended over antiplatelet therapy alone for carefully selected patients aged 18-60 years with cryptogenic stroke attributed to PFO. 2, 3

Specific Criteria for PFO Closure (All Must Be Met):

• Age 18-60 years 2
• Confirmed nonlacunar embolic ischemic stroke or TIA with positive neuroimaging or cortical symptoms 2
• Thorough evaluation by stroke specialist confirming PFO as most likely cause after excluding alternate etiologies 2
• No indication for chronic anticoagulation 2, 3

Evidence Supporting Closure:

• Pooled analysis of 6 trials (3,740 patients) showed annualized stroke incidence of 0.47% with closure versus 1.09% with medical therapy alone (adjusted HR 0.41,95% CI 0.28-0.60) 1
• Number needed to treat is 20 over 5 years to prevent one stroke 3
• In PASCAL "probable" patients (younger, no vascular risk factors, high-risk PFO features), closure reduced recurrent stroke by 90% (HR 0.10,95% CI 0.03-0.35) 1

For Patients Over 60 Years

PFO closure is NOT recommended for patients over 60 years old, regardless of stroke history. 2, 3

• Antiplatelet therapy alone is recommended unless separate indication exists for anticoagulation 2
• Older patients did not demonstrate benefit from closure and face higher procedural risks 1

Medical Therapy Specifications

For patients not undergoing closure or awaiting procedure:

• Aspirin 75-325 mg daily is the primary antiplatelet option, with alternative antiplatelet agents acceptable 3
• Either antiplatelet or anticoagulant therapy is acceptable for secondary prevention in patients under 60 who don't undergo closure 2
• No significant difference was found between warfarin and aspirin in the PICSS trial (9.5% vs 17.9% event rate, HR 0.52, p=0.28), though the study was underpowered 2

Post-closure antiplatelet regimen:

• Dual antiplatelet therapy initially after PFO closure, transitioning to long-term single antiplatelet therapy 3

Procedural Complications of PFO Closure

Device-Related Adverse Events

• Major complications occur in 1.5-2.3% of patients undergoing device closure 2
• Minor complications occur in 7.9% of patients 2
• Device-related adverse events occur in 5.9% of cases overall 3

Atrial Fibrillation Risk

Atrial fibrillation is the most common post-procedural complication, occurring in 4.6-6.6% of patients after PFO closure. 2, 3

• Most cases are transient and occur in the immediate post-procedural period 2
• This represents a significantly higher rate compared to 0.4% in medical therapy groups 2
• Patients must understand and accept this risk before proceeding with closure 2

Procedural Details and Recovery

• Procedure typically takes under 2 hours with 1-day hospital stay 3
• Most activities can be resumed within days, with full recovery within weeks 3

Critical Pitfalls to Avoid

Inappropriate Patient Selection

Do NOT close PFO in the following scenarios:

• Patients over 60 years old 2, 3
• Patients where PFO is likely incidental rather than causal (use RoPE score and PASCAL classification) 2, 3, 1
• Patients requiring chronic anticoagulation for other indications 2, 3
• For primary stroke prevention in asymptomatic individuals 5

Diagnostic Pitfalls

• PFO prevalence is 25% in the general population, making it critical to distinguish incidental from pathogenic PFO 6, 1
• Use the RoPE score to predict probability of pathogenic PFO: scores <3 suggest PFO prevalence similar to general population (23%), while scores 9-10 indicate 77% prevalence 1
• PASCAL classification system combines RoPE score with anatomical features (large shunt, atrial septal aneurysm) to categorize PFO as "probable," "possible," or "unlikely" cause 1

Other Complications

• Decompression sickness in high-volume divers, compressed-air tunnel workers, and high-altitude aviators may warrant PFO closure after multiple recurrences in those wishing to continue high-risk activities 2
• Migraine with aura has been associated with PFO, but insufficient evidence exists to recommend closure for this indication 2
• Right-sided cardiac disease with elevated right atrial pressure predisposes to right-to-left shunting, and PFO closure may provide intermediate-term palliation for cyanosis 2