How should recurrent in‑stent restenosis be treated in a patient with a drug‑eluting stent placed in the left circumflex artery?

Treatment of Recurrent In-Stent Restenosis

For recurrent in-stent restenosis in a drug-eluting stent, consider CABG as the preferred option if the patient has diffuse ISR and suitable anatomy, particularly in the left circumflex artery where repeat PCI carries high re-restenosis risk. 1

Treatment Algorithm Based on Clinical Scenario

First-Line Approach: CABG for Recurrent Diffuse ISR

• CABG is useful over repeat PCI (Class 2a recommendation) specifically for symptomatic recurrent diffuse ISR to reduce recurrent events 1
• This is particularly relevant when:
  • The patient has already failed one DES intervention
  • The ISR pattern is diffuse rather than focal
  • The vessel is suitable for bypass grafting
  • The patient is an acceptable surgical candidate

Alternative: Vascular Brachytherapy

• Brachytherapy may be considered (Class 2b) when 1:
  • Multiple stent layers already exist
  • The artery is unfavorable for another DES
  • The patient is not a CABG candidate
  • This avoids adding yet another metal layer

Drug-Coated Balloons (DCB)

• DCB are recommended (Class I) for treatment of ISR within DES 2
• DCB avoid additional stent layers while delivering antiproliferative therapy
• Recent evidence suggests paclitaxel-coated balloons are most effective 3
• However, DCB may not prevent recurrence in truly refractory cases 4

Repeat DES Only in Select Cases

• If repeat PCI is chosen despite recurrence, everolimus-eluting stents show best efficacy among DES types 1
• This should be reserved for:
  • Focal rather than diffuse patterns
  • Patients who are absolutely not CABG candidates
  • When brachytherapy is unavailable

Critical Decision Points

Pattern of ISR matters:

• Diffuse ISR → strongly favor CABG over repeat PCI 1
• Focal ISR → DCB or repeat DES may be reasonable

Number of prior interventions:

• Recurrent (≥2 episodes) → CABG or brachytherapy preferred 1
• First ISR episode → DES or DCB acceptable

Vessel characteristics:

• Large vessel, suitable anatomy → CABG strongly preferred for recurrent ISR 1
• Small vessel, poor surgical target → brachytherapy or DCB

Common Pitfalls to Avoid

1. Repeatedly stenting recurrent ISR creates multiple metal layers, worsening outcomes and limiting future options 1

2. Ignoring the mechanism: Use intravascular imaging (IVUS/OCT) to identify:

   • Stent underexpansion (needs high-pressure balloon)
   • Neoatherosclerosis (may need atherectomy)
   • Stent fracture (requires different approach)
   • Pure neointimal hyperplasia (DCB appropriate) 5, 6

3. Overlooking systemic causes: Consider rare triggers in truly refractory cases:

   • Stent hypersensitivity 4
   • Antiphospholipid syndrome 7
   • Poor medication compliance

4. Inadequate medical therapy: Intensive medical management is vital regardless of revascularization choice 1

Practical Management Framework

For your patient with recurrent ISR in the left circumflex DES:

1. Assess ISR pattern (angiography ± intravascular imaging)

   • Diffuse → proceed to step 2
   • Focal → consider DCB

2. Evaluate CABG candidacy

   • Suitable anatomy + acceptable risk → CABG is the answer
   • Not a candidate → proceed to step 3

3. If CABG not feasible:

   • Brachytherapy available → use it
   • Brachytherapy unavailable → DCB (paclitaxel-coated)
   • Last resort → repeat DES (everolimus-eluting)

The 2021 ACC/AHA/SCAI guidelines explicitly state that in patients with recurrent episodes of restenosis despite repeat PCI with DES, CABG may be the preferred approach if anatomy is suitable 1. This is expert consensus (Class 2a, Level C-EO) recognizing that repeat PCI in this setting has diminishing returns and increasing risk of further failure.