EndoCoronary-Rhenium-Irradiation-Study - ECRIS

Description:

The goal of the trial was to evaluate the efficacy of β-irradiation with a liquid rhenium-188–filled balloon compared with control in patients with de novo or restenotic lesions.

Hypothesis:

Treatment with β-irradiation with a liquid rhenium-188–filled balloon following successful percutaneous coronary intervention (PCI) will result in a reduced target lesion restenosis rate at six months compared with control.

Study Design

Study Design:

Patients Enrolled: 225
Mean Follow Up: 6 months (angiographic) and 12 months (clinical)
Mean Patient Age: Mean age 63 years
Female: 23%

Patient Populations:

Successful angioplasty with or without stenting, age 40-80 years, ischemia by symptoms or exercise testing, lesion in a native coronary artery or venous bypass graft, and ischemic tolerance ≥1 minute during angioplasty

Exclusions:

Acute MI; unprotected main stem disease; strong vessel tortuosity; pregnancy; contraindication to aspirin, ticlopidine, clopidogrel, or heparin; and life expectancy ≤6 months

Primary Endpoints:

Target lesion restenosis rate at six months

Secondary Endpoints:

1) Restenosis rate of the total segment including edge stenoses; and 2) incidence of MACE, defined as cardiac death, myocardial infarction (MI), and repeat revascularization of the target vessel

Drug/Procedures Used:

Patients underwent PCI with or without stenting at the discretion of the investigator. After a successful procedure, patients were then randomized to rhenium-188 β-irradiation with 22.5 Gy in 0.5-mm tissue depth (n=113) or no additional intervention (n=112).

Concomitant Medications:

Prior to angioplasty, patients received 10,000 U heparin with an adjusted activated clotting time of >280 seconds. All patients received aspirin (100 mg/day) throughout the study. Patients with stents also received ticlopidine (250 mg twice daily) or clopidogrel (75 mg/day) for four weeks to six months.

Principal Findings:

There was no crossover from randomized treatment to control. Overall, 71% of the lesions were de novo lesions. Lesion and procedural characteristics were similar between the two arms, with the exception of stenting, which was used significantly more frequently in the control arm (63% vs. 45%, p<0.02).

The mean irradiated segment length was 35 mm and mean irradiation time was 6.8 ± 3.6 minutes. Late loss at six-month angiographic follow-up was lower in the irradiated arm versus the control arm in both the target lesion (0.11 ± 0.54 vs. 0.69 ± 0.81 mm, p<0.0001) and the total segment (0.22 ± 0.67 vs. 0.70 ± 0.82 mm, p<0.0001). Similar results were observed in the subgroup of patients with de novo lesions (0.08 vs. 0.72 for target lesion, p<0.0001), stenting (p<0.002), and no stenting (p<0.05).

The primary endpoint of binary restenosis was significantly lower in the irradiated arm at the target lesion (6.3% vs. 27.5%, p<0.0001) as well as in the total segment (12.6% vs. 28.6%, p<0.007). Similar results were seen in the subgroup of patients with de novo lesions (6.3% vs. 23.9% for target lesion, p<0.004). Target vessel revascularization tended to occur less frequently in the irradiated arm (8.0% vs. 16.1%, p=0.06), but there was no difference in six-month major adverse cardiac event (MACE) rates (14.2% vs. 21.4%, p=NS).

Interpretation:

Among patients undergoing successful PCI with or without stenting for de novo or restenotic lesions, treatment with β-irradiation with a liquid rhenium-188–filled balloon was associated with a reduction in the primary endpoint of target lesion restenosis at six-month angiographic follow-up, as well as reductions in late lumen loss.

Similar results were seen in patients with de novo lesions at both the target site and the total segment, an interesting subgroup finding given the lack of benefit in total segment restenosis in the BETACATH and PREVENT radiation trials in the de novo lesion subgroup. Nonetheless, the finding should be interpreted with caution, given the subgroup nature of the analysis. The rhenium-188 liquid-filled balloon was designed to be self-centering and to adapt to the individual vessel segment without need for intravascular ultrasound for dosimetry.

References:

Hoher M, Wohrle J, Wohlfrom M, et al. Intracoronary beta-irradiation with a rhenium-188-filled balloon catheter: a randomized trial in patients with de novo and restenotic lesions. Circulation. 2003;107:3022-7.

Keywords: Beta Particles, Coronary Restenosis, Coronary Vessels, Angioplasty, Balloon, Coronary


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