Repeat intracoronary beta-brachytherapy using a rhenium-188-filled balloon catheter for recurrent restenosis in patients who failed intracoronary radiation therapy

Coronary stenting with the sirolimus-eluting stent in patients with restenosis after intracoronary brachytherapy: results from the prospective multicentre German Cypher Stent Registry

BACKGROUND

Treatment of restenosis following intracoronary brachytherapy (ICB) is still a challenging problem. Implantation of sirolimus-eluting stents (SES) in this setting may be an option to be evaluated.

METHODS AND RESULTS

We analysed the prospective multicentre SES registry, the German Cypher Stent Registry. 7,445 patients treated with an SES during percutaneous coronary intervention (PCI) were registered. Out of these patients, 61 (0.8%) were treated for restenosis after ICB: 56 patients with completed follow-up could be evaluated. Median age was 65 years, with 80% male patients. 48% of patients had a prior myocardial infarction and 25% had already coronary bypass surgery (CABG). Type B2 lesion was present in 40% and type C lesion in 22.4%. Event rates from SES implantation until 6.6 months follow-up were death 0%, myocardial infarction 3.6%, stroke 2.1%. Target vessel revascularization rate (TVR) was 16.4%, and major adverse cardiovascular or cerebral events (MACCE) or TVR occurred in 17.9% of patients. This TVR rate was higher compared with that of other patients treated with an SES: 8.4% (P = 0.04). During 65 months follow-up MACCE or TVR occurred in 44.6% of patients.

CONCLUSIONS

The treatment of lesions after ICB occurred in 0.8% out of all patients treated with an SES. Clinical event rates during early follow-up were low. However, the TVR rate was 16.4%, which was significantly higher when compared with other SES-treated patients (8.4%, P = 0.04). The treatment of restenosis after ICB with SES seems to be safe and reasonably effective; however, there might be a late catch-up phenomenon.

Increased expression of nuclear NF-kappaB after coronary artery balloon injury can be inhibited by intracoronary beta-irradiation

PURPOSE

Molecular mechanisms by which balloon angioplasty injury-induced neointimal hyperplasia can be reduced by intravascular brachytherapy are unclear. We investigated the role of nuclear factor-kappaB (NF-kappaB) in neointimal hyperplasia following intracoronary irradiation.

MATERIALS AND METHODS

Fifty-four coronary arteries from 30 pigs were divided into 6 groups: sham control, balloon angioplasty injury alone, beta-irradiation at doses of 14 or 20 Gy, and 14 or 20 Gy beta-irradiation immediately followed by balloon injury. Coronary arteries were injured by overstretch balloon angioplasty and then the arteries were irradiated using a Rhenium-188 ((188)Re) beta-emitting solution-filled balloon. Pigs were scarified one day or one week after coronary interventions for molecular detection and six weeks after the procedures for histological examination.

RESULTS

Six weeks after coronary interventions, the histological results show that balloon angioplasty injury had induced intimal hyperplasia in coronary artery but the response was significantly reduced by 28% and 60% when the injury was immediately treated by 14 and 20 Gy (188)Re beta-irradiation, respectively. The expression of arterial NF-kappaB p65, intercellular adhesion molecule-1 (ICAM-1), and vascular cell adhesion molecule-1 (VCAM-1) were detected at one day and one week after the procedures. The treatment of balloon injury could significantly induce the NF-kappaB p65 expression in both gene and protein levels, and such induction could be significantly reduced by (188)Re beta-irradiation at dose of 20 Gy. However, the similar result on the regulation of gene expression affected by the beta-irradiation could not be observed in ICAM-1 and VCAM-1.

CONCLUSION

The inhibitory effect of intracoronary brachytherapy on neointimal formation following overstretch balloon angioplasty could involve inhibition of NF-kappaB p65.