Treatment of diffuse IN-stent restenosis with Drug-Eluting stents vs. intracoronary bEta-raDiation therapy: INDEED Study

Background: We compared sirolimus-eluting stent (SES) implantation and intracoronary brachytherapy (ICBT) for diffuse bare metal in-stent restenosis (ISR) to identify more effective treatment modality. Methods: Patients (n = 129) with diffuse ISR (lesion length ≥ 10 mm) were randomly assigned to either SES implantation (n = 65, group I) or beta-radiation with ¹⁸⁸Re-MAG₃-filled balloon (n = 64, group II). The radiation dose was 20 Gy at a depth of 1.0 mm into the vessel wall. The primary end point was late loss in analysis segment at 6 months. The secondary end points were 6-month angiographic restenosis and 1-year major adverse cardiac events (MACE) including myocardial infarction (MI), cardiac death, and target lesion revascularization (TLR). Results: Baseline characteristics were similar between two groups. The lesion length was 27.52 ± 13.98 mm in group I and 27.75 ± 14.25 mm in group II (p = 0.927). Late loss in analysis segment at 6 months was smaller in group I than in group II (0.15 ± 0.62 vs. 0.55 ± 0.69 mm, p = 0.003). Angiographic restenosis for analysis segment at 6 months was 8.0% (4/50) in group I and 30.2% (16/53) in group II (p = 0.006). One MI and two deaths (all from group I) occurred during follow-up. TLR (4.6% vs. 18.8%, p = 0.014) and MACEs (7.7% vs. 18.8%, p = 0.073) were lower in group I than group II at 1 year. Conclusion: Compared to ICBT, SES implantation for diffuse bare metal ISR showed less late loss, lower restenosis, and a trend toward lower 1-year MACEs. SES implantation appears to be superior to ICBT for treating diffuse ISR.