Usefulness of intracoronary brachytherapy for in-stent restenosis with a 188Re liquid-filled balloon

Comparative efficacy of interventional therapies and devices for coronary in-stent restenosis: A systematic review and network meta-analysis of randomized controlled trials

Background

In-stent restenosis (ISR) has become a significant obstacle to interventional therapy for atherosclerotic cardiovascular disease. The optimal percutaneous coronary intervention (PCI) strategy for patients with coronary ISR remains controversial. This network meta-analysis (NMA) was aimed to compare and estimate the effectiveness of different PCI strategies and commercial devices for the treatment of patients with coronary ISR.

Methods

In present study, we systematically searched PubMed, Embase, Web of Science, and Cochrane Library from database inception to October 20, 2022, to identify randomized controlled trials. We included studies comparing various PCI strategies for the treatment of any type of coronary ISR. The study was registered with PROSPERO, CRD 42022364308.

Results

We included 44 eligible trials including 8479 patients, 39 trials comparing the treatment effects of 10 PCIs, and 5 trials comparing the efficacy between different types of drug-eluting stent (DES) or drug-coated balloon (DCB) devices. Among the PCIs, everolimus-eluting stent was the optimal strategy considering target lesion revascularization (TLR), percent diameter stenosis (%DS), and binary restenosis (BR), and sirolimus-coated balloon was the optimal strategy considering late lumen loss (LLL). In the comparison of commercial devices, the combination strategy excimer laser coronary angioplasty plus SeQuent Please paclitaxel-coated balloon showed promising therapeutic prospects.

Conclusions

DCB and DES remain the preferred treatment strategies for coronary ISR, considering both the primary clinical outcome (TLR) and the angiographic outcomes (LLL, BR, %DS). Personalized combination interventions including DCB or DES hold promise as a novel potential treatment pattern for coronary ISR.

Intravascular radiation therapy with a Re-188 liquid-filled balloon in patients with in-stent restenosis

OBJECTIVE

The aim of this study was to evaluate the feasibility and safety of intravascular radiation therapy (IVRT) using Re-188 filled balloon system in patients with in-stent stenosis.

METHODS

A total of 39 patients with in-stent restenosis were enrolled as the IVRT (22 patients) and control groups (17 patients) of this study after a successful coronary angioplasty. For irradiation the angioplasty balloon was replaced by a noncompliant balloon of the same diameter but 10 mm longer in length with a proximal and distal radio-opaque marker to deliver the dose of 18 Gy at 0.5 mm depth from the surface of the balloon into the vessel wall. Angiographic follow-up was performed after 6 months.

RESULTS

The length of the irradiated segment was between 9.14 and 22 mm and the diameter between 2.5 and 3 mm. In the IVRT group, two patients who did not receive antiplatelet therapy had myocardial infarction. Four patients who presented with stable angina earlier also had angiographically documented in-stent occlusion (two patients) and edge stenosis (two patients) of the target lesion and received angioplasty (18.1%). In the control group, three patients with recurrent angina and four asymptomatic patients had documented in-stent occlusion angiographically at 6 months and these seven patients underwent target lesion revascularization (41.2%). The overall restenosis rate in the IVRT and control groups were 23.91 and 39.86%, respectively (P=0.013). No complications were documented, except anginal pain and ST segment changes.

CONCLUSION

Our results indicated that the Re-188 liquid-filled balloon is feasible, safe, and effective in patients with in-stent restenosis.

A meta-analysis of randomised controlled trials assessing drug-eluting stents and vascular brachytherapy in the treatment of coronary artery in-stent restenosis

OBJECTIVE

We undertook a meta-analysis of randomised trials assessing the outcome of vascular brachytherapy (VBT) or DES for the treatment of coronary artery ISR.

METHODS AND RESULTS

Studies utilising DES or VBT for ISR were identified by a systematic search. Data was pooled and combined overall effect measures were calculated for a random effect model in terms of deaths, myocardial infarctions, revascularisation, binary restenosis, mean late luminal loss and major adverse cardiac events (MACE). Fourteen eligible studies (3103 patients) were included. Neither therapy had any effect on mortality or myocardial infarction rate. VBT reduced the rate of revascularisation (RR 0.59, 95%CI 0.50-0.68), MACE (RR 0.58, 95%CI 0.51-0.67), binary restenosis (RR 0.51, 95%CI 0.44-0.59) and late loss (-0.73 mm, 95%CI -0.91 to -0.55 mm) compared to balloon angioplasty and selective bare metal stents (BMS) alone at intermediate follow-up and MACE (RR 0.72, 95%CI 0.61-0.85) at long-term follow-up. DES reduced the rate of revascularisation (OR 0.51, 95% CI 0.36-0.71), MACE (OR 0.55, 95% CI 0.39-0.79) and binary restenosis (OR 0.57, 95% CI 0.40-0.81) compared to VBT but follow-up was limited to 9 months.

CONCLUSIONS

VBT improves the long-term outcome of angioplasty compared with BMS alone in the treatment of ISR. DES appears to provide similar results to that of VBT during short-term follow-up.

The effect of locally delivered c-myc antisense oligonucleotides combined with intravascular brachytherapy of 188Re liquid-filled balloon therapy on vascular smooth muscle cell proliferation in rabbit iliac arteries after injury with a balloon catheter

Poststenting restenosis is a significant clinical problem that involves vascular smooth muscle cell (VSMC) proliferation. We primarily investigated the effect of c-myc antisense oligodeoxynucleotides (ASODNs) combined with 188Re radiation therapy on VSMC proliferation in rabbit common iliac arteries injured by the porous balloon catheter to explore the therapeutic potential of the combined therapy for the prevention of restenosis. The iliac arteries in rabbits were injured with balloon catheters, and radiation therapy was carried out with a 2.5 mm balloon catheter filled with 188Re (8 or 15 Gy), and ASODNs (300 microg) were applied to the adventitia introduced using a pluronic gel releasing system and a lipofectin delivery system. After 3 weeks, the animals were killed and defined segments of arteries were sectioned. The histological sections were stained using alpha-actin immunohistochemistry staining. The positive alpha-actin ratios were calculated and analyzed statistically among groups. In contrast to the rate of alpha-actin positive cell staining in the control group, the rate of alpha-actin positive cell staining did not decrease (P > 0.05) in the 188Re-irradiated group (8 Gy). However, in the ASODN-treated group, the 188Re-irradiated group (15 Gy), and the combined ASODN - 188Reirradiated groups (8 or 15 Gy), the ratios had markedly decreased (P < 0.01). The effect of the combined group (ASODNs + 188Re (15 Gy)) provided the lowest level of alpha-actin positive cell staining (P < 0.01). The ASODNs (300 microg) effectively decreased VSMC poliferation. The effect of the 188Re radiation on the VSMCs depended on the dosage. The ASODNs (300 microg) and combined 188Re irradiation effectively lowered VSMC proliferation, and the effect was better than that achieved with any other treatment.

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

BACKGROUND

Conventional percutaneous coronary intervention (PCI) in restenotic lesions after brachytherapy failure is associated with a high recurrence rate of restenoses and revascularizations. Intracoronary brachytherapy using a liquid rhenium-188-filled balloon in de novo or restenotic lesions safely and effectively reduced restenosis rates. We report clinical and angiographic data regarding the safety and efficacy of rhenium-188 brachytherapy in restenoses after brachytherapy failure.

METHODS

Fourteen patients with restenosis after brachytherapy failure received rhenium-188 beta-brachytherapy. Follow-up was performed angiographically after 6 months and clinically after 12 months. Primary clinical endpoint was the incidence of major adverse cardiac events (MACE) defined as any death, myocardial infarction or repeat revascularization in the target vessel within 12 months. Secondary angiographic endpoints were the binary restenosis rate and late loss in the total segment including edge effects at 6 months.

RESULTS

The prescribed dose of 22.5 Gy (n=12) or 30 Gy (n=2) was successfully delivered in all patients. In two lesions, a bare-metal stent was implanted. The mean length of the irradiated segment was 40.0+/-15.7 mm. The mean diameter of the irradiation balloon was 2.96+/-0.37 mm. Angiographic follow-up was done in 13 of 14 patients. There was no edge stenosis or coronary aneurysm. Within the total segment, late loss was 0.39+/-0.64 mm and late loss index was 0.18+/-0.40 with a binary restenosis rate of 23%. Twelve months' clinical follow-up was available in all patients, which showed a MACE rate of 7% due to one target lesion revascularization (TLR).

CONCLUSIONS

Intracoronary beta-brachytherapy with a liquid rhenium-188-filled balloon in restenoses after intracoronary radiation therapy failure including 12 months combined antiplatelet therapy is safe with respect to vessel thrombosis, late coronary occlusion or aneurysm formation. With limited use of stenting, angiographic and clinical follow-up for repeat brachytherapy were favorable and it is associated with low restenosis and target vessel revascularization rate.

Intracoronary β-brachytherapy using a rhenium-188 filled balloon catheter in restenotic lesions of native coronary arteries and venous bypass grafts

PURPOSE

We have previously demonstrated the efficacy of intracoronary beta-brachytherapy using a liquid (188)Re-filled balloon in a randomised trial including de novo lesions. Percutaneous coronary interventions in restenotic lesions and in stenoses of venous bypass grafts are characterised by a high recurrence rate for restenosis and re-interventions. Against this background, we wanted to assess the impact of intracoronary beta-brachytherapy using a liquid (188)Re-filled balloon in restenotic lesions in native coronary arteries and venous bypass grafts.

METHODS

In 243 patients, beta-brachytherapy with 22.5 Gy was applied at a tissue depth of 0.5 mm. Patients were followed up angiographically after 6 months and clinically for 12 months. The primary clinical endpoint was the incidence of MACE (death, myocardial infarction, target vessel revascularisation). Secondary angiographic endpoints were late loss and binary restenosis rate in the total segment.

RESULTS

All irradiation procedures were successfully performed. A total of 222 lesions were in native coronary arteries; 21 were bypass lesions. Mean irradiation length was 41.6+/-17.3 mm (range 20-150 mm) in native coronary arteries and 48.1+/-33.9 mm (range 30-180 mm) in bypass lesions; the reference diameter was 2.57+/-0.52 mm and 2.83+/-0.76 mm, respectively. There was no vessel thrombosis during antiplatelet therapy. Angiographic/clinical follow-up rate was 84%/100%. MACE rate was 17.6% in the native coronary artery group and 38.1% in the CABG group (p<0.03). Binary restenosis rate was 22.5% and 55.6% (p<0.01), and late loss was 0.38+/-0.72 mm and 1.33+/-1.11 mm (p<0.001), respectively.

CONCLUSIONS

We conclude that intracoronary beta-brachytherapy with a liquid (188)Re-filled balloon using 22.5 Gy at a tissue depth of 0.5 mm in restenotic lesions is safe. It is associated with a low binary restenosis rate, resulting in a low occurrence rate of MACE within 12 months in restenotic lesions in native coronary arteries but not in vein grafts.

Intracoronary radiotherapy with a 188Rhenium liquid-filled angioplasty balloon system in in-stent restenosis: a single-center, prospective, randomized, placebo-controlled, double-blind evaluation

BACKGROUND

In cases of in-stent restenosis, intracoronary radiotherapy with beta-emitters and gamma-emitters has been shown to reduce the risk of repeat restenosis. The present randomised, placebo-controlled study addresses the question of whether intracoronary radiotherapy applied by the easy-to-handle Rhenium liquid-filled angioplasty balloon system is also able to reduce the angiographic re-restenosis rate in stents.

METHODS AND RESULTS

At our center, from May 2000 to December 2003, 165 patients (mean age 64+/-10, median 65 years; 127 men, 38 women) with symptomatic in-stent restenosis underwent either intracoronary brachytherapy or sham procedure. Index clinical and angiographic parameters were largely comparable in both groups. Radiation therapy was performed with a standard percutaneous transluminal coronary angioplasty (PTCA) balloon catheter inflated with liquid Rhenium in the redilated in-stent restenosis for 240-890, mean 384+/-125 s with low pressure (3 atm) in order to reach 30 Gy at 0.5 mm depth of the vessel wall. In 82 patients, intracoronary radiotherapy was carried out without complications, but one of the 83 patients who underwent sham procedure suffered small myocardial infarction. During follow-up, stent thrombosis with subsequent non-Q-wave myocardial infarction occurred in one patient in each group (6 days and 8 months after the procedure, respectively). At 6 months after the index procedure, repeat angiography was performed in 156 of the 164 patients with successful procedure (rate 95%): restenosis (stenosis >50% in diameter) or reocclusion was observed in only 19 of 78 (=24%) patients of the radiation but in 31 of 78 (=40%) patients of the sham procedure group (P=0.04). Event-free survival (free of death, myocardial infarction, target vessel revascularization) at 1 year was 87% for patients being radiated and 74% for patients having undergone sham procedure (P=0.05).

CONCLUSIONS

Intracoronary radiation therapy with the liquid-filled beta-emitting Rhenium balloon is not only easy to perform, safe, and comparably inexpensive but also an effective option to prevent repeat restenosis and the need for target vessel revascularization in cases of in-stent restenosis.

Two-year clinical follow-up results of intracoronary radiation therapy with rhenium-188-diethylene triamine penta-acetic acid-filled balloon

We investigated the 2-year clinical follow-up results as well as 6-month angiographic and clinical follow-up results of intracoronary radiation therapy using a rhenium-188-diethylene triamine penta-acetic acid ((188)Re-DTPA)-filled balloon system. The study comprised of 161 patients with significant de novo (83%) or in-stent restenosis (17%) lesions. Irradiation to deliver 17.6 Gy at a depth of 1.0 mm into the vessel wall was carried out after successful intervention. At 6-month follow-up, binary restenosis developed with significantly lower frequency in the radiation group than in the control group (24.3% vs. 46.3%; P = 0.009), although target lesion revascularization rate did not show significant benefit. At 2-year follow-up, cumulative target lesion revascularization rate was not significantly different between radiation group (n = 86) and control group (n = 75; 20.0% vs. 26.0%; P = 0.368). The rate of major adverse cardiac events including death, myocardial infarction, and target lesion revascularization did not show significant difference between two groups either (22.3% vs. 30.1%; P = 0.266). In conclusion, although significant reduction in restenosis rate was noted at 6-month angiographic follow-up, intracoronary radiation therapy mostly in patients with de novo lesion did not show significant clinical benefit in 6-month and 2-year follow-up results. The benefit was noted only in a small subgroup of patients with in-stent restenosis.

Effects of β-radiation with a 188rhenium-filled balloon catheter system on non-stented adjacent coronary artery segments

BACKGROUND

The effects of beta-radiation with a (188)rhenium ((188)Re)-filled balloon catheter system on angiographically normal reference segments have not been well defined.

METHODS

In the Seoul National University Post-Angioplasty Rhenium irradiation (SPARE) trial, patients with de novo or restenotic lesions were first treated with a conventional catheter-based technique and then randomized to either a radiation group or a control group. Irradiation was performed using a (188)Re-filled conventional balloon catheter system. Among 97 radiation group enrolled in this study from April 1998 through May 2001, 20 patients with de novo lesions who received brachytherapy with a balloon at least 10 mm longer than the length of an implanted stent, were selected and their post-intervention and follow-up intravascular ultrasound (IVUS) images were analyzed. Each reference segment was divided into two segments; full dose-irradiation with injury segment (irradiated segment; from the stent edge to the radiopaque balloon markers), and low dose-irradiation without injury segment (edge segment; 5-mm long segment proximal or distal to the location of radiopaque markers). In control group, serial IVUS analysis was available only in 10 patients, and IVUS parameters of the non-stented adjacent segments in these patients were compared to those of irradiated segments in radiation group patients.

RESULTS

Forty irradiated and 38 edge segments of the 20 radiation group patients were analyzed. In proximal irradiated segments, no significant changes were found in external elastic membrane (EEM), lumen or in the plaque plus media (P&M) areas. In distal irradiated segments, significant increases in the EEM (12.5+/-4.5 to 14.0+/-5.0 mm(2), P<0.01) and P&M areas (5.5+/-2.0 to 6.6+/-2.3 mm(2), P<0.01) were found to occur without a change in lumen area. In proximal edge segments, P&M areas were significantly increased (9.0+/-1.7 to 10.5+/-2.6 mm(2), P=0.03). No significant changes in EEM, lumen or P&M areas were observed in the distal edge segments. Comparisons between the irradiated segments (n=40) in the radiation group and the non-stented adjacent segments (n=19) in the control group showed a significant difference in the percentage change of EEM areas (18.5+/-33.2% in radiation group vs. -3.1+/-32.1% in control group, P=0.02).

CONCLUSIONS

beta-radiation with a (188)Re-filled conventional balloon catheter system appears to have no significant deleterious effect on angiographically normal reference segments over a 6 months follow up after brachytherapy.

Intracoronary radiotherapy with a 188rhenium liquid-filled PTCA balloon system in in-stent restenosis: acute and long-term angiographic results, as well as 1-year clinical follow-up

BACKGROUND

Intracoronary radiotherapy with beta- and gamma-emitters has been shown to reduce the risk of restenosis after balloon angioplasty and after coronary stenting. The present study addresses the question whether intracoronary radiotherapy using the (188)rhenium liquid-filled PTCA balloon system is feasible, safe and effective in cases of in-stent restenosis. Acute and long-term angiographic results as well as clinical events within 1 year after the procedure were evaluated.

METHODS AND RESULTS

From September 1999 to April 2000, 41 patients (mean age 60+/-10 years, 33 male, 8 female) with symptomatic in-stent restenosis underwent repeat PTCA and immediate intracoronary brachytherapy. After successful repeat PTCA (residual stenosis less than 30% in diameter), a second standard PTCA catheter was inflated with liquid (188)rhenium in the redilated in-stent restenosis for 315-880, mean 540+/-155 s with low pressure (3 atm) in order to reach 30 Gy at 0.5 mm depth of the vessel wall. In all patients with successful reintervention, intracoronary radiotherapy was unproblematically performed; in 16 patients, 21 new stents were implanted during the procedure-either immediately before or after radiation therapy. During follow-up, four episodes of stent thrombosis with subsequent myocardial infarction occurred in three patients (8 days, 37 days, 5 months and 6 months after the procedure, respectively). This complication was seen exclusively in patients with newly implanted stents. One patient of the stent group died suddenly 46 days after the procedure. All 40 surviving patients underwent repeat angiography in cases of repeat angina or routinely 6 months after brachytherapy, respectively. In the redilated target vessels without new stenting, restenosis (stenosis >50% in diameter) or reocclusion was observed in only 5 of 25 (=20%) cases, but in the restented target lesions, in 10 of 15 (=67%). Event-free survival (death, myocardial infarction, TVR) at 1 year after repeat dilatation and subsequent brachytherapy was 80% for patients not newly stented, but only 44% for patients with new stents.

CONCLUSIONS

Intracoronary radiation therapy with the liquid-filled beta-emitting (188)rhenium balloon is a safe and effective therapy in cases of in-stent restenosis. The positive effect of irradiation, however, is abolished if a new stent is needed. In the not newly stented patients, 1-year follow-up is encouraging.

Automated preparation of 188Re-labeled radiopharmaceuticals for endovascular radiation therapy

We have developed an automated system for the preparation of highly concentrated 188Re-perrhenate, diethylenetriamine pentaacetic acid (DTPA) and mercaptoacetyltriglycine (MAG3). The three procedural steps include concentration of 188Re-perrhanerate, chelation and purification and sterilization. The steps are operated by a small micro-controller. The eluted 188Re-perrhenate of 15 GBq/18 ml from 37 GBq 188W/188Re-generator was concentrated to 1.2 ml in 10 +/- 0.5 min with a recovery yield of 95 +/- 1.5%. We obtained the highest radiochemical yield of 95.4 +/- 2.8% and 98.5 +/- 1.2% for 188Re-DTPA and MAG3 at the oil bath temperatures of 95-97 degrees C and 93-97 degrees C, respectively.

Intracoronary beta-irradiation with a rhenium-188-filled balloon catheter: a randomized trial in patients with de novo and restenotic lesions

BACKGROUND

Restenosis requiring reintervention is the main limitation of coronary angioplasty. Intracoronary irradiation reduces neointimal proliferation. We studied the efficacy of a self-centering liquid rhenium-188-filled balloon catheter for coronary beta-brachytherapy.

METHODS AND RESULTS

After successful coronary angioplasty with or without stenting, 225 patients (71% de novo lesions) were randomly assigned to receive 22.5 Gy intravascular beta-irradiation in 0.5-mm tissue depth (n=113) or to receive no additional intervention (n=112). Clinical and procedural data did not differ between the groups except a higher rate of stenting in the control group (63%) compared with the rhenium-188 group (45%, P<0.02). After 6 months of follow-up, late loss was significantly lower in the irradiated group compared with the control group, both of the target lesion (0.11+/-0.54 versus 0.69+/-0.81 mm, P<0.0001) and of the total segment (0.22+/-0.67 versus 0.70+/-0.82 mm, P<0.0001). This was also evident in the subgroup of patients with de novo lesions and independent from stenting. Binary restenosis rates were significantly lower at the target lesion (6.3% versus 27.5%, P<0.0001) and of the total segment (12.6% versus 28.6%, P<0.007) after rhenium-188 brachytherapy compared with the control group. Target vessel revascularization rate was significantly lower in the rhenium-188 (6.3%) compared with the control group (19.8%, P=0.006).

CONCLUSIONS

Intracoronary beta-brachytherapy with a rhenium-188 liquid-filled balloon is safe and efficiently reduces restenosis and revascularization rates after coronary angioplasty.

[Intracoronary brachytherapy: a meta-analysis]

Intracoronary brachytherapy aims at a reduction of in-stent restenosis by lessening neo-intimal proliferation. To assess its clinical potential, a systematic review of the literature indexed in the standard biomedical bibliographic databases selected eight prospective randomized clinical trials; seven of them, comparing coronary brachytherapy and non-treatment or placebo, have been included in the present meta-analysis. This analysis confirms the angiographic benefit of this procedure, as reported in the individual studies; it also shows, however an excess of clinical adverse effects not exhibited by any individual trial. Therefore, intracoronary brachytherapy cannot be recommended as routine practice, while one cannot rule out its interest in special situations.