Intracoronary b-Radiation Therapy Inhibits Recurrence of In-Stent Restenosis (original) (raw)
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Three-year follow-up after intracoronary gamma radiation therapy for in-stent restenosis
Cardiovascular Radiation Medicine, 2001
Background: The Washington Radiation for In-Stent Restenosis Trial (WRIST) is a double-blinded randomized study evaluating the effects of intracoronary radiation therapy (IRT) in patients with in-stent restenosis (ISR).Methods: One hundred and thirty patients with ISR (100 native coronary and 30 vein grafts) underwent PTCA, laser ablation, rotational atherectomy, and/or additional stenting (36% of lesions). Patients were randomized to either Iridium-192 IRT or placebo, with a prescribed dose of 15 Gy to a 2-mm radial distance from the center of the source.Results: Angiographic restenosis (27% vs. 56%, P=.002) and target vessel revascularization (TVR; 26% vs. 66%, P<.001) were dramatically reduced at 6 months in IRT patients. Between 6 and 36 months, IRT compared to placebo patients had more target lesion revascularization (TLR; IRT=17% vs. placebo=2%, P=.002) and TVR (IRT=17% vs. placebo=3%, P=.009). At 3 years, the major adverse cardiac event (MACE) rate was significantly reduced with IRT (39% vs. 65%, P=.003).Conclusions: In WRIST, patients with ISR treated with IRT using 192Ir had a marked reduction in the need for repeat target lesion and vessel revascularization at 6 months, with the clinical benefit maintained at 3 years.
Repeated intracoronary beta radiation for recurrent in-stent restenosis
Catheterization and Cardiovascular Interventions, 2002
More than 70% of percutaneous coronary interventions are followed by a stent implantation. In-stent restenosis still occurs in 20-30% of patients and remains a therapeutic challenge. At present only vascular brachytherapy has been shown to be an effective treatment option. We report here one case of recurrent in-stent restenosis after vascular brachytherapy that was successfully treated by a second beta radiation treatment.
Beta-radiation for coronary in-stent restenosis
Catheterization and Cardiovascular Interventions, 2000
To determine the feasibility and safety of an intracoronary beta-radiation device in preventing the recurrence of in-stent restenosis (ISR) after successful angioplasty, we studied 37 patients treated with beta-radiation (30-mm strontium-90 source) after angioplasty. The mean reference diameter was 2.9 ؎ 0.5 mm, and 62% of lesions were diffuse, including four total occlusions. Beta-radiation was successfully delivered in 36 of 37 (97%) cases. Over the course of 7.1 ؎ 4.5 mo follow-up, there were no myocardial infarctions and three deaths: one from preexisting malignancy, one from progressive cardiac failure, and one from sudden cardiac death. Target vessel revascularization (TVR) was performed in seven of 36 (19%) patients. Thirty patients underwent angiography at 6 mo; three (10%) experienced restenosis (diameter stenosis > 50%) at the target site, four (13%) had edge stenoses, and two (7%) had late (> 1 mo) thrombotic occlusions. Beta-radiation for ISR is associated with encouragingly low rates of target lesion restenosis and TVR. Further improvements are needed to solve the limitations of the edge effect and late occlusion.
Intracoronary Radiation for Prevention of Restenosis Dose Perturbations Caused by Stents
2000
Background—Intravascular irradiation with b-emitters has been proposed for inhibition of restenosis in coronary arteries after balloon angioplasty or stent implantation. Previous studies have shown the effectiveness of g-radiation to prevent recurrent restenosis, even in the presence of an implanted stent. The limited range of b-particles compared with g-radiation, however, opens the question of whether absorption and scattering of b-particles by
American Heart Journal, 2005
Background It is an ongoing concern that intracoronary brachytherapy may possibly just delay the problem of in-stent restenosis (blate catch upQ). For g-radiation, 3 placebo-controlled studies have shown the maintenance of the initially positive effect after 2 years, but similar data do not exist for h-radiation. STents And Restenosis Trial (START) was the first placebocontrolled randomized trial for in-stent restenosis with h-radiation; herein, we report the 2-year clinical follow-up. Methods and Results Two hundred and forty-four patients were randomized to active treatment, 232 patients to placebo (nonactive source train) treatment. The primary end point of efficacy was target vessel revascularization (TVR); primary safety end point was any major adverse cardiac event (MACE) at 8 months and 2 years. Two-year clinical outcome in patients receiving brachytherapy was based on 195 of 244 original patients (79.9%) and in the placebo arm on 183 of 232 original patients (78.9%). TVR was significantly reduced by 25%; from 36.6% (placebo) to 27.5% (brachytherapy) remained significant after 2 years (RR .7 [.57-.98], 95% CI À9.2 [À17.5-0.8]). The Kaplan-Meier analysis for TVR and MACE showed improvement beginning approximately 90 days after radiation and remained almost constant for the 2 following years. Freedom from TVR was significantly increased from 62.4% F 3.8% to 71.6% F 3.3% (P = .027) and freedom from MACE from 58.9% F 3.7% to 68.0% F 3.4% (P = .035). Conclusions The START trial shows for the first time that the initial beneficial effects of intracoronary brachytherapy with h-radiation using 90 Sr/ 90 Y are maintained at 2-year clinical follow-up period.
Use of restenting should be minimized with intracoronary radiation therapy for in-stent restenosis
2003
Restenting at the time of intracoronary radiation therapy (IRT) for in-stent restenosis (ISR) potentially increases the risk of late total occlusion (LTO) of the treated vessel. Prolonged antiplatelet therapy with clopidogrel (6 months) has been shown to be effective in reducing LTO risk. The purpose of this study was to assess the impact of restenting on clinical outcomes following IRT for ISR with 6 months of clopidogrel. We retrospectively evaluated 1,275 patients with 6-months clinical follow-up who were enrolled in radiation trials for ISR using ␥and -emitters conducted at Washington Hospital Center. Patients were analyzed according to whether additional stents were deployed at the time of IRT. The predominant indication for restenting was to optimize the final angiographic result in the event of tissue prolapse or to cover edge dissections. All patients received a minimum of 6 months of clopidogrel. Baseline clinical and angiographic characteristics were similar between the restented and nonrestented groups. Radiation was delivered successfully in all cases. At 6 months, patients treated with additional stents and IRT had a significantly higher rate of target vessel revascularization than patients without additional stents (24.6% vs. 18.7%; P ؍ 0.011). Restenting caused more frequent late thrombosis, late total occlusion, and Q-wave myocardial infarction than no restenting (4.0% vs. 2.2%, P ؍ 0.09; 6.1% vs. 4.3%, P ؍ 0.14; and 1.9% vs. 0.4%, P ؍ 0.009, respectively). Restenting for the treatment of ISR is associated with increased adverse events and should be avoided after intracoronary radiation therapy for in-stent restenosis, as restenting results in a higher recurrence rate and the potential for increased late total occlusion.
International Journal of Radiation Oncology*Biology*Physics, 2002
Purpose: To evaluate the safety and efficacy of a 40-mm 90 Strontium/ 90 Yttrium source train in the management of in-stent restenosis within native coronary arteries. Methods and Materials: This multicenter, prospective registry was designed to compare the results of patients with in-stent restenosis treated with a 40-mm source train to the placebo arm of the previously reported randomized Stents and Radiation Trial (START). All patients entered in the registry were treated with repeat balloon angioplasty followed by intravascular brachytherapy. Radiation dose was prescribed based on vessel size. 18 Gy was delivered at 2 mm for vessel diameters between 2.75 and 3.35 mm, and 23 Gy was used for vessels between 3.36 and 4.0 mm. The efficacy endpoints for the START 40 registry included a reduction in the target lesion revascularization (TLR) rate, target vessel revascularization rates, and target vessel failure (TVF) at 8 months. Secondary angiographic efficacy endpoints were binary restenosis at 8 months, in-stent minimum luminal diameter (MLD), and late loss. The safety endpoints included major adverse cardiac events as well as late aneurysm formation. The registry was designed to allow a statistically valid comparison of these results to the placebo group of the START 30 trial. Quantitative angiographic analysis was performed on the 8-month follow-up examination. Rates of restenosis were evaluated for various segments of the treated vessel. A separate analysis was performed to evaluate the relationship between vessel injury length and the radiated segment. Results: A total of 207 patients were entered into the START 40 registry. The postprocedure angiographic results, including the postprocedure MLD and percent diameter stenosis, were similar between the START 40 patients and the placebo group from the START trial in the stented segment of the treated vessel. Eight-month angiographic follow-up was available on 150 patients from the registry. The TLR rate was significantly reduced when compared to the placebo group (11% vs. 22.4% respectively, p ؍ 0.008). A similar reduction was seen in terms of target vessel revascularization (15.9% vs. 24.1%, p ؍ 0.03). The 8-month MLD was found to be significantly larger in . The difference seen in the clinical endpoint of TVF (19.3% vs. 25.9%) did not reach statistical significance (p ؍ 0.1). Analysis of the procedural angiograms revealed mismatch between the length of vessel injured and the location of the 90% isodose in 46% of the treated cases. Angiographic analysis revealed that geographic miss was associated with a higher rate of binary restenosis (32% vs. 18% p ؍ 0.04) in the analysis segment. Conclusions: This multicenter registry demonstrates the safety and efficacy of a 40-mm 90 Strontium/ 90 Yttrium source train in the management of patients with in-stent restenosis. Restenosis rates were lowered with the use of this longer source train when compared to the placebo arm of the START trial for lesions with a maximum vessel injury length of 20 mm. Angiographic analysis identified the importance of the accurate delineation of injury length and correct source positioning. These results support the continued use of beta radiation for the treatment of this disease process.
2000
were then blindly randomized to receive either intracoronary g-radiation with 192Ir (15 Gy) or placebo. Four independent core laboratories blinded to the treatment protocol analyzed the angiographic and intravascular ultrasound end points of restenosis. Procedural success and in-hospital and 30-day complications were similar among the groups. At 6 months, patients assigned to radiation therapy required less target lesion revascularization and