Intracoronary Beta-radiation Research Articles

Late outcome after intracoronary beta radiation brachytherapy: a matched-propensity controlled ten-year follow-up study

Increased major adverse cardiac events (MACE) beyond six months after intracoronary β radiation brachytherapy (IRBT) are a major concern. The aim of this study was to evaluate the 10-year clinical outcome after IRBT. From 1997 to 2002, 301 consecutive patients treated with IRBT were included prospectively, whereafter 602 control patients treated with conventional percutaneous coronary intervention (PCI) were matched by propensity score methodology. MACE was defined as all-cause death, any myocardial infarction or any revascularisation. Median follow-up duration was 9.7 years. Mortality rates in both groups were similar. Cumulative 5-month, 2-, and 10- year MACE-free survival rates of IRBT patients were 89%, 56% and 29%, respectively, while those of the control patients were 90%, 76% and 52%, respectively (p < 0.001). The difference in the MACE rate was mainly driven by target vessel revascularisation (TVR) (p < 0.001). Furthermore, two or more repeat TVRs were needed in 12% of IRBT patients and in only 6% of control patients (p < 0.01). Adjusted hazard ratios for IRBT-associated all-cause mortality and MACE were 1.0 (95% CI 0.7-1.5) and 1.8 (95% CI 1.5-2.2), respectively. IRBT was associated with increased MACE between five months and two years of follow-up, mainly driven by repeat revascularisations. Similar event rate after two years indicate that there were no very late adverse effects related to IRBT.

Intracoronary Beta‐Radiation Therapy for In‐stent Restenosis: Long‐Term Success Rate and Prediction of Failure

The following retrospective observational study assesses the long-term results of intracoronary beta-radiation therapy for patients with in-stent restenosis. Beta-radiation has been used to treat patients with coronary in-stent restenosis. However, long-term clinical success using this technique has not at this time been established. Two-hundred and thirteen consecutive patients received intracoronary brachytherapy (noncentered beta-emitter, Novoste BetaCath) for in-stent restenosis and were followed up over a period of 39.1 +/- 18.4 months. The combined end-point was defined as a major adverse clinical event (MACE)and comprised mortality, acute myocardial infarction, or target vessel revascularization (TVR). MACE occurred in 110 patients (51.6%): death in 27 patients (12.7%), acute myocardial infarction in 8 patients (3.8%), TVR in 90 patients (42.3%). TVR comprised percutaneous coronary reinterventions in 76 patients (35.7%) and coronary bypass surgery in 24 patients (11.3%). Secondary end-point was determined as target vessel failure and occurred in 93 patients (43.7%). Of note, the frequency of at least two previous target lesion interventions as well as impairment of left ventricular function was associated with reduced success rate, whereas other clinical parameters did not indicate outcome after treatment with intracoronary radiation therapy. During the mean, a period of 3 years, more than half of the patients receiving intracoronary radiation therapy reached primary end-point, representing, in the main, TVR. During this period a mortality rate of nearly 13% was documented. These results signify a delayed, though continued, restenotic process after index procedure.

Efficacy and Safety of Absorbable Metallic Stents with Adjunct Intracoronary Beta Radiation in Porcine Coronary Arteries

Absorbable metallic stents (AMS) utilizing Mg alloy carry advantages over permanent metallic stents because of their potential to eliminate stent thrombosis, chronic inflammation, or artifacts with noninvasive imaging. These stents, however, are associated with a modest degree of late recoil and intimal hyperplasia. The aim of the study was to test whether adjunct vascular brachytherapy (VBT) compared to AMS alone can overcome these limitations. Juvenile domestic pig coronary arteries underwent implantation of either AMS (n = 11) with prior adjunct VBT utilizing Sr/Y-90 beta source seeds, with a dose of 24 Gy at 2 mm from the source, or AMS alone (n = 11). At 28 days following intravascular ultrasound, vessels were harvested and analyzed by histomorphometry. Intravascular ultrasound analysis indicated that at follow-up, though statistically not significant, lumen and stent areas in the segments deployed with AMS following radiation were larger than those deployed with AMS alone (3.94 +/- 1.38 and 3.53 +/- 1.75 vs. 2.99 +/- 1.05 and 3.58 +/- 1.48). Extrastent plaque and intrastent plaque areas in the same segments were smaller (2.76 +/- 0.82 and 0.24 +/- 0.47 vs. 3.25 +/- 1.94 and 0.58 +/- 0.81). Morphometric data indicate that vessels in the VBT + AMS group showed characteristics of delayed healing and re-endothelialization. Neointimal area was significantly lower in the VBT + AMS group (0.49 +/- 0.34) compared to AMS (1.3 +/- 0.62, P = 0.001). Lumen area of the VBT + AMS was larger when compared with AMS alone (2.49 +/- 0.82 vs. 1.75 +/- 0.51, P = 0.02). VBT as an adjunct to AMS further reduces the intimal hyperplasia and improves the lumen area when compared to AMS alone but does not have any impact on late recoil.

Intracoronary β-irradiation for the treatment of de novo lesions: 5-Year clinical follow-up of the BetAce randomized trial

Vascular brachytherapy (VBT) has been used for the prevention of restenosis. Despite initial positive results, long-term follow-up has shown a progressive loss of benefit in clinical outcome after beta-irradiation. We report the 5-year follow-up of the BetAce trial. This prospective, randomized, single-blind trial included 61 patients treated for 64 de novo coronary lesions: 31 patients (33 stenoses) were treated with bare metal stents (control group), and 30 patients (31 stenoses) were treated with intracoronary beta-irradiation at the time of stented angioplasty (VBT group). Baseline and procedural data were similar between treatment arms. At 6 months, VBT reduced the need for target vessel revascularization (13% vs 35.5%, P = .04), but there was no significant difference in the 6- and 12-month event-free survival when clinical events were ranked. Between 1 and 5 years, an increasing number of target vessel failures was observed in both groups, leading to a similar long-term clinical outcome at 5 years (event-free survival 43% and 45% in the VBT and control groups, respectively, log-rank 0.001, P = .9). Beta-irradiation in de novo coronary lesions significantly reduced in-stent recurrences at 6 months compared with standard procedures. However, this initial benefit was not sustained in the long term. The results of this randomized study confirm the delayed and progressive restenotic process after beta-irradiation and stent implantation in de novo lesions.

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-κB) 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, β-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 (188Re) β-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 188Re β-irradiation, respectively. The expression of arterial NF-κB 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-κB p65 expression in both gene and protein levels, and such induction could be significantly reduced by 188Re β-irradiation at dose of 20 Gy. However, the similar result on the regulation of gene expression affected by the β-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-κB p65.

Feasibility and safety of intra‐coronary Beta irradiation with144Ce/Pr for prevention of restenosis after percutaneous transluminal coronary angioplasty of in‐stent restenotic lesions

Endovascular brachytherapy is a proven and efficacious treatment of coronary in-stent restenosis with established long-term benefit. Owing to its complexity and logistic inconveniences, brachytherapy did not find wide acceptance, especially in the current drug-eluting stents era. We conducted a single center, non-randomized pilot trial with 144Ce/Pr, utilizing a new high-energy Beta emitting source, for prevention of restenosis after percutaneous treatment of in-stent restenotic lesions. Thirty consecutive patients presenting in-stent restenosis were enrolled in the study. After conventional balloon angioplasty, 144Ce/Pr was applied to the dilated coronary segment at a dose of 21Gy. Technical feasibility, safety and efficacy of 144Ce/Pr at 9 months clinical and angiographic follow-up were tested. Thirty-seven arterial segments were irradiated with 100% technical success and no in-hospital major adverse cardiac events (MACE). Five MACE were observed (13.5% of the treated segments) during 9 months follow-up, including four target lesion revascularizations and one episode of acute coronary syndrome secondary to sudden late thrombotic occlusion of the irradiated segment. The study confirmed the safety and the feasibility of the intra-coronary Beta irradiation utilizing the 144Ce/Pr source. It also shows some practical advantages compared to traditional Gamma or other Beta sources. Considering the high-risk restenosis profile of the selected patients (i.e. diffuse in-stent restenosis, bifurcation lesions, small vessels) these results are encouraging in terms of restenosis prevention. Late acute thrombosis remains a problem requiring further improvement.

Comparison Between Sirolimus-Eluting Stents and Intracoronary Catheter-Based Beta Radiation for the Treatment of In-Stent Restenosis

We report the outcomes of patients who had in-stent restenosis (IRS) that was treated with intravascular brachytherapy (IVBT) or sirolimus-eluting stent (SES) implantation. The benefit of IVBT for treating ISR is well documented. SES implantation decreases first-time ISR and, in preliminary reports, has been used to treat ISR. Fifty consecutive patients who had ISR were treated; the first 25 patients underwent SES implantation and the next 25 patients were treated with IVBT using a beta-Cath System (a 40-mm strontium-90/yttrium-90 source). Quantitative angiographic and intravascular ultrasound follow-up were performed at 5.2 +/- 1.1 and 12.1 +/- 1.2 months; clinical follow-up was performed at 15 months. SES deployment and IVBT were successful in all patients. At 12-month follow-up, 8 patients who underwent IVBT had angiographic recurrence (4 in the stent and 4 at the stent edge); only 1 patient who underwent SES implantation developed recurrent ISR. At 12 months, in-stent late luminal loss was similar between the SES and IVBT groups (0.35 +/- 0.45 vs 0.34 +/- 0.46 mm, p = 0.9); however, in-stent net luminal gain was higher in the SES group than in the IVBT group (1.32 +/- 0.13 vs 0.57 +/- 0.19 mm, p <0.0001), and in-lesion late luminal loss was higher in the IVBT group (0.48 +/- 0.32 vs 0.16 +/- 0.42 mm, p = 0.004). At 12 months, intravascular ultrasound stent volume obstruction was higher after IVBT versus than after SES implantation (38.7% vs 6.7%, p <0.0001). At 15-month clinical follow-up, 64% and 96% (p <0.01) of patients who underwent IVBT and SES implantation, respectively, were free of major adverse cardiac events. In conclusion SES implantation for the treatment of ISR was effective and superior to catheter-based IVBT in preventing recurrent neointimal proliferation and angiographic restenosis at 1-year follow-up.

Comparison of a centered 32P source wire system with a noncentered 90Sr/Y brachytherapy system for intracoronary β-radiation following PCI of diffuse in-stent restenosis

We investigated the potential impact of differences in effective radiation dose between the centered Guidant 32P source wire system and the noncentered Novoste 90Sr/Y BetaCath system on clinical and angiographic outcomes of intracoronary brachytherapy for the prevention of in-stent restenosis. From 10/00 to 05/04, a total of 400 patients underwent percutaneous coronary intervention (PCI) with brachytherapy for diffuse in-stent restenosis at our institution. Following balloon dilatation, patient Group A (n=200) was treated with the centered 32P Galileo source wire system, patient Group B (n=200) was treated with the noncentered 90Sr/Y BetaCath radiation system. In Group A, the prescribed dose of 20 Gy was applied in 1-mm depth of the vessel wall. In Group B, the prescribed dose of 18.4 Gy was applied for visual reference vessel sizes >2.7 and <3.35 mm, 23 Gy for >3.36 and <4.00 mm, and 25.3 Gy for >4.00 mm, each calculated at a distance of 2 mm from the center line of the radiation source. Patients received aspirin and clopidogrel over 12 months. Primary endpoint was target lesion revascularization (TLR) at 6 months. Secondary endpoints were the binary restenosis rate and major adverse cardiac event (MACE) at 30 days and 6 months. At 30 days, one patient of each group underwent PCI at a nontarget lesion (0.5%). At 6 months, MACEs were equally distributed in both groups. Target lesion revascularization at 6 months was 5.9% in Group A and 9.2% in Group B (P=.08). Binary angiographic restenosis rate at 6 months was 5.5% in Group A and 11.2% in Group B (P=.014). Intracoronary beta-radiation using the centered 32P source wire system yielded a significant reduction of recurrence rate compared to the noncentered 90S/Y BetaCath system after PCI of diffuse in-stent restenosis. There was a nonsignificant trend toward reduction of TLR among patients treated with the centered 32P source wire system.

Intracoronary radiation therapy using a novel beta emitter for in-stent restenosis

Intracoronary beta-radiation therapy reduces in-stent restenosis (ISR). We aimed to determine the safety and feasibility of intracoronary radiation therapy (IRT) utilizing tungsten (188W), a beta emitter. A total of 30 patients with angiographic evidence of ISR in a previously treated native coronary artery underwent percutaneous coronary intervention (PCI; balloon angioplasty, ablation by atherectomy, or laser angioplasty). After the intervention, a noncentered delivery catheter with a side guide 0.014-in. wire carrying a tungsten (188W) coil, with an active length of 33 mm, was inserted. Patients were randomized to a radiation dose of 18, 22, or 25 Gy at 2 mm from the center of the source. Aspirin and Plavix, at 300 mg loading dose, were administered prior to intervention. Plavix 75 mg/day was prescribed for 6 months after the procedure. At 6 months follow-up, the overall binary angiographic restenosis rate was 18.8%. Target vessel revascularization (TVR) was 23% and target lesion revascularization related major adverse cardiac events (TLR-MACE) was 13.3%, without any intergroup differences. A comparison with the original Washington Radiation for In-stent restenosis Trial (WRIST) radiation cohort utilizing an 192Iridium source (prescription dose 15 Gy at 2 mm from the source) showed similar TVR and TLR-MACE rates of 30% and 18%, respectively. The TVR and TLR-MACE rates in the WRIST placebo cohort were 70% and 66%, respectively. Vascular brachytherapy with tungsten (188W) is feasible and safe. The 6-month clinical outcomes are similar to the original WRIST radiation 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.

Clinical and angiographic outcomes of cardiac transplant patients treated with intracoronary beta-radiation for in-stent restenosis: A case series

Background Vascular brachytherapy (VBT) is effective for the treatment of in-stent restenosis (ISR), however, the effect of VBT clinical and angiographic outcomes of patients with ISR who have undergone orthotopic heart transplantation (OHT) requires further study. Methods All OHT patients with ISR treated with VBT using the Novoste Beta-Cath System at Rush University Medical Center were identified, and the clinical and angiographic outcomes were evaluated. Results Four OHT patients with ISR who underwent VBT were identified. The mean age was 48.5 years, and the mean duration posttransplantation was 7.5 years. The mean reference coronary vessel diameter was 3.06 mm. The primary interventional device utilized prior to VBT was cutting balloon angioplasty (CBA) in 75% and percutaneous balloon angioplasty in 25%. The mean duration of follow-up after VBT was 11 months. There were no deaths attributable due to cardiac disease, no myocardial infarction, and no target vessel revascularization on follow-up. Overall survival during this period was 75%, with one mortality due to stroke 8 months after VBT. Conclusions VBT for the treatment of ISR in patients who have undergone OHT appears safe and feasible and is associated with acceptable clinical and angiographic outcomes.

Evolution of angiographic restenosis rate and late lumen loss after intracoronary beta radiation for In-Stent restenotic lesions

The aim of this study was to investigate the time course of angiographic restenosis rate and late loss after successful percutaneous coronary intervention and vascular brachytherapy with β-irradiation using strontium-90/yttrium-90 in 98 patients who were prospectively enrolled into a quantitative angiographic and clinical follow-up protocol at 6, 12, and 24 months after the index procedure, regardless of their symptom status. Actuarial restenosis rates measured 11.2 ± 5% at 6 months of follow-up, 24.5 ± 5% at 12 months, and 28.5 ± 6% at 24 months, respectively. Late loss of the stent segment during the first 6 months measured 0.38 ± 0.40 mm (6 to 12 months: 0.25 ± 0.38 mm; 12 to 24 months: 0.16 ± 0.32 mm), of the injured segment 0.27 ± 0.21 mm (6 to 12 months: 0.21 ± 0.26 mm; 12 to 24 months: 0.13 ± 0.24 mm), of the irradiated segment 0.18 ± 0.29 mm (6 to 12 months: 0.19 ± 0.31 mm; 12 to 24 months: 0.11 ± 0.27 mm), and of the analysis segment 0.18 ± 0.36 mm (6 to 12 months: 0.17 ± 0.29 mm; 12 to 24 months: 0.11 ± 0.20 mm). Restenosis after angioplasty and β-irradiation of in-stent restenotic lesions is not complete within 6 months but is sustained with a gradual decrease over 24 months.

1102-51 Long-term efficacy of intracoronary beta-radiation for the treatment of in-stent restenosis: An angiographic and intravascular ultrasound analysis of the late catch-up phenomenon

1102-51 Long-term efficacy of intracoronary beta-radiation for the treatment of in-stent restenosis: An angiographic and intravascular ultrasound analysis of the late catch-up phenomenon

P2223 Long-term outcome after intracoronary beta radiation therapy

P2223 Long-term outcome after intracoronary beta radiation therapy

803 Evolution of late lumen loss after intracoronary beta-radiation ? a prospective quantitative angiographic study at 3, 6, 12 and 24 months

803 Evolution of late lumen loss after intracoronary beta-radiation ? a prospective quantitative angiographic study at 3, 6, 12 and 24 months

804 Long-term efficacy of intracoronary beta-radiation for treatment of diffuse in-stent restenosis: evidence for late restenosis

804 Long-term efficacy of intracoronary beta-radiation for treatment of diffuse in-stent restenosis: evidence for late restenosis

Intracoronary beta-irradiation 24 hours after percutaneous coronary interventions: A serial volumetric intravascular ultrasound study

Intracoronary beta-irradiation 24 hours after percutaneous coronary interventions: A serial volumetric intravascular ultrasound study

Beta-radiation therapy for long lesions in native coronary vessels: A matched comparison between de novo and in-stent restenotic lesions

Objective: The purpose of this study was to evaluate effectiveness and to compare clinical outcome of intracoronary beta-radiation to treat long lesions (>20 mm) in patients with de novo stenosis vs. patients with in-stent restenosis (ISR). Methods: A matched comparison of 44 patients with 63 de novo lesions and 48 patients with 63 ISR lesions (>20 mm) treated with intracoronary beta-radiation was performed. Results: Stents were implanted in 65.1% of de novo and 19% of ISR lesions ( P=.001). Radiation doses delivered were 17.2±3.0 vs. 20.3±3.0 Gy at 2 mm from the source center for de novo and ISR lesions. There was no difference in the incidence of in-hospital events. Clinical follow-up at 16.4±6.7 months showed no difference in major adverse cardiac events (MACE) between de novo and ISR patients (27.3% vs. 25%, P=.8). Late total occlusions (LTOs) occurred in eight patients (four in each group) treated with stents at the time of radiation and after discontinuation of ticlopidine. By multivariate analysis, stent implantation was the only predictor of late occlusions (OR 8.25, 95% CI 1.73–38.46, P<.008). Restenosis rates were similar for de novo and ISR lesions (29.3% vs. 23.2%, P=.46), as well as target lesion revascularization (TLR) and target vessel revascularization (TVR) rates (22.7% vs. 22.9% and 29.5% vs. 29.2%, respectively). Conclusions: Intracoronary beta-radiation gives comparable results when used to treat de novo or ISR lesions provided new stent implantation can be avoided. Long-term combined antiplatelet therapy is mandatory for patients who receive new stents at the time of radiation treatment.

Long-Term Follow-Up Results of Intracoronary Beta-Radiation Therapy with a Rhenium-188 Diethylene Triamine Penta-Acetic Acid-Filled Balloon

Background and Objectives:Intracoronary irradiation has emerged as a successful intervention for the treatment of restenosis. However, the radiation process is complex, difficult and hard to perform. On the contrary, intracoronary radiation therapy using a Re-DTPA-filled balloon system is simple and inexpensive. The short-term follow-up results of this system have been reported, but the long-term results remain to be elucidated. The object of this study is to evaluate the short and long-term follow-up results of intracoronary radiation using a ReDTPA-filled balloon system in restenotic lesions. Subjects and Methods:Thirty-eight patients, with restenotic lesion after previous percutaneous coronary intervention, were selected from the SPARE trial (Seoul National University Post-Angioplasty RhEnium irradiation trial). There were 27 cases in the irradiation group, with 11 in the control group. Irradiation was performed in the restenotic lesions after successful interventions. The results of 6month angiographic and 6-month and 3-year clinical follow-up data were compared between the two groups. Results:A 6-month angiographic follow-up was performed in 33 patients (87%), 25 in the radiation group and 8 in control. Binary restenosis developed in 1 of 25 (4%) and 4 of 8 (50%) in the radiation and control groups, respectively (p=0.008). At the 6-month clinical follow-up, there were no significant differences in the event rates between the two groups. At the 3-year clinical follow-up, there was a significant difference in the target vessel revascularization:2 of 27 (7.4%) and 5 of 11 (45.4%) in the radiation and control groups, respectively (p=0.017). There were no deaths or myocardial infarctions. Conclusion:Radiation therapy using a ReDTPA-filled balloon system is feasible, and may be effective in improving the long-term outcomes in restenotic lesions. (Korean Circulation J 2003;33 (8):723-729)

Sustained platelet activation following intracoronary beta irradiation

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