Intracoronary beta-irradiation prevents excessive in-stent neointimal proliferation in de novo lesions of patients with high plasma ACE levels. The BetAce randomized trial.

BACKGROUND: This study evaluated vascular brachytherapy (VBT) as a potent antiproliferative treatment to prevent in-stent restenosis (ISR) after coronary angioplasty of de novo lesions in patients carrying the D allele of the I/D polymorphism of the ACE gene and high ACE plasma levels (>34 U/l). METHODS AND MATERIALS: A prospective randomized trial was designed to detect a 30% improvement in the minimal lumen diameter (MLD) of the stenotic artery, as measured by quantitative coronary analysis (QCA), 6 months following VBT at the time of stented angioplasty. All patients were carriers of the D allele of the ACE gene, with plasma ACE levels >34 U/l. RESULTS: Thirty-one patients (33 stenoses) were allocated to stent implantation (control group) and 30 patients (31 stenoses) to VBT and stented angioplasty. After angioplasty, in-stent MLD was similar in the two groups. At 6 months in the control group, in-stent MLD had decreased to 1.74+/-0.8 versus 2.25+/-1.05 mm in the VBT group (P=.04). The mean in-stent diameter was 2.3+/-0.8 mm in the control group versus 2.9+/-1.05 mm after VBT (P=.02), and the restenosis rate was 37.5% versus 17.9%, respectively (P=.08). At 6 months, a higher need for target vessel revascularization (TVR) was observed in the control group: 35.5% versus 13.3% (P=.04). CONCLUSIONS: This randomized study confirms that patients with high plasma ACE concentrations are exposed to an increased risk for ISR after coronary stenting. The preventive use of VBT in these patients reduced neointimal formation by 65% such that the MLD at follow-up was increased by 29% compared with the control group.

Angiographic and three-dimensional intravascular ultrasound analysis of combined intracoronary beta radiation and self-expanding stent implantation in human coronary arteries.

This study tested the combination of vascular brachytherapy (VBT) and self-expanding Wallstent implantation in coronary lesions of patients at high risk for restenosis as assessed angiographically by quantitative coronary analysis and by 3-dimensional intravascular ultrasound analysis. Twenty-nine "de novo" lesions were managed with a self-expanding stent alone (n = 19) or with a self-expanding stent after beta-VBT (n = 10) in 27 patients who had been identified by high levels of plasma angiotensin-converting enzyme as being prone to myointimal growth after stent implantation. At 6 months, the increase in stent strut diameter was similar in the 2 groups by quantitative coronary analysis and 3-dimensional intravascular ultrasound (Delta mean stent strut diameter -0.33 +/- 0.3 vs -0.40 +/- 0.3 mm, p = 0.5; Delta stent area -11.8 +/- 6.1 vs -12.0 +/- 6.1 mm(2), p = 0.9; Delta stent volume -96.9 +/- 112 vs -83.5 +/- 73 mm(3), p = 0.7; for groups treated with VBT and self-expanding stents and only self-expanding stents, respectively). In-stent neointimal proliferation was decreased in the group treated with VBT and self-expanding stents (minimal luminal diameter 2.5 +/- 0.8 vs 1.88 +/- 0.8 mm, p = 0.04) by quantitative coronary analysis (minimal luminal area 6.7 +/- 2.5 vs 4.1 +/- 1.9 mm(2), p = 0.01), by intravascular ultrasound, and proliferation volume (84.6 +/- 66.4 vs 159.2 +/- 103.5 mm(3), p = 0.05) by 3-dimensional intravascular ultrasound. Positive vessel and luminal remodelings were observed in 50% of the group treated with VBT and self-expanding stents and in 11% of the group treated only with self-expanding stents (p = 0.02). The combined use of VBT and self-expanding stents is a novel approach that enlarges vascular lumen by preventing vessel constriction and neointimal proliferation. The feasibility and good results of this experimental approach suggest that the simultaneous use of these 2 technologies may be an interesting alternative for difficult vascular districts with high restenosis rates, such as peripheral circulation in the lower limbs.