Chronic total occlusion due to diffuse in-stent restenosis: is brachytherapy the solution?

Area of Science:

• Cardiovascular Medicine
• Interventional Cardiology
• Radiation Oncology

Background:

• Percutaneous coronary intervention (PCI) for chronic total occlusions (CTO) has higher reocclusion rates than non-total occlusions.
• Intracoronary brachytherapy (ICBT) is effective for preventing in-stent restenosis, but data for totally occluded lesions are limited.

Purpose of the Study:

• To assess the long-term outcomes of patients with totally occluded in-stent restenosis treated with intracoronary gamma radiation.
• To determine if CTO is an independent predictor of adverse events following ICBT for in-stent restenosis.

Main Methods:

• 100 patients (103 vessels) with diffuse in-stent restenosis underwent PCI and catheter-based iridium-192 irradiation.
• 15 patients (14.5%) had CTO at the target vessel site at baseline.
• Long-term follow-up included clinical visits, telephone interviews, and repeat angiography in symptomatic patients.

Main Results:

• Patients with CTO required longer radiation sources (53.3% vs. 23.9%, p=0.04).
• Major adverse cardiac events (MACE) were significantly higher in the CTO group (66.7% vs. 28.4%, p=0.009) over a mean follow-up of 47.5 months.
• CTO was the single independent predictor of one-year MACE (RR 16.2, p < 0.0001).

Conclusions:

• Intracoronary gamma radiation appears less effective for preventing restenosis in totally occluded in-stent lesions compared to non-total occlusions.
• Chronic total occlusion is an independent predictor of worse long-term outcomes in patients treated with ICBT for in-stent restenosis.