Is genicular artery embolization contraindicated in patients with rheumatoid arthritis (RA)?

Genicular Artery Embolization in Rheumatoid Arthritis

Genicular artery embolization (GAE) is not contraindicated in patients with rheumatoid arthritis, but it should be recognized that all published evidence and clinical trials have exclusively studied osteoarthritis populations, not RA patients.

Critical Evidence Gap

The available evidence base for GAE consists entirely of osteoarthritis studies:

• All systematic reviews and clinical trials of GAE have enrolled only patients with knee osteoarthritis, with no published data on RA patients 1, 2, 3, 4
• The largest prospective FDA investigational device exemption trial specifically enrolled patients aged 40-80 years with moderate or severe knee OA (Kellgren-Lawrence grade 2-4) who had failed conservative therapy 2
• A 2021 systematic review of 11 studies (225 patients, 268 knees) included only OA populations 1

Pathophysiologic Considerations

The mechanism of GAE targets synovial hypervascularity, which differs fundamentally between OA and RA:

• GAE works by embolizing genicular arteries supplying hyperemic synovium identified on angiography and cone-beam CT 2, 3
• In OA, synovial inflammation is mechanically driven and localized 1
• In RA, synovial inflammation is systemic, immune-mediated, and requires disease-modifying antirheumatic drugs (DMARDs) as the cornerstone of treatment 5

RA Management Framework

RA requires DMARD therapy following a treat-to-target strategy as the primary treatment approach 5:

• Rheumatoid arthritis should be treated with DMARDs and follow a treat-to-target management strategy 5
• Surgical interventions are not included in current ACR RA guidelines because they are not frequently part of current RA management 5
• Optimum RA treatment outcomes are achieved through interprofessional teams providing expert patient-centered care 5

Clinical Decision Algorithm

If considering GAE for an RA patient with knee pain:

1. First, ensure optimal DMARD therapy - Confirm the patient is on appropriate disease-modifying therapy per 2021 ACR guidelines 5

2. Distinguish pain etiology - Determine whether knee pain is from active RA synovitis versus concurrent OA (common in RA patients) using clinical assessment and imaging 5

3. Optimize RA disease activity - If RA is active, escalate immunosuppressive therapy rather than pursuing procedural interventions 5

4. Consider GAE only if:

   • RA disease activity is well-controlled on DMARDs 5
   • Concurrent knee OA is documented as the pain source 1
   • Conservative OA treatments have failed 2
   • The patient understands this is off-label use without safety/efficacy data in RA populations 2, 3

Safety Considerations Specific to RA

RA patients may have unique risks not captured in OA trials:

• RA patients have increased cardiovascular risk requiring proactive management 5
• Many RA patients are on immunosuppressive therapy that could theoretically affect wound healing, though GAE adverse events in OA populations were minor (transient skin discoloration 11.6%, focal skin ulceration in 7 subjects, small asymptomatic bone infarcts in 2 subjects) 1, 2
• RA patients may have cervical spine instability and positioning considerations 5

Evidence Quality for OA Populations

For context, GAE in OA populations demonstrates:

• Technical success rate of 99.7% 4
• 67% reduction in VAS pain scores at 12 months 2
• 61% reduction in WOMAC scores at 12 months 2
• 47.4% of patients maintained ≥50% symptom reduction at 24 months 3
• Acceptable safety profile with only minor adverse events 1, 2, 3

However, these outcomes cannot be extrapolated to RA patients given the fundamental differences in disease pathophysiology.