Two-year angiographic follow-up of intracoronary Sr90 therapy for restenosis prevention after balloon angioplasty

Comparison of six-month angiographic and three-year outcomes after sirolimus-eluting stent implantation versus brachytherapy for bare metal in-stent restenosis

To evaluate long-term effectiveness of sirolimus-eluting stent (SES) implantation for diffuse bare metal in-stent restenosis (ISR), we compared 6-month angiographic and long-term (3-year) clinical outcomes of SES implantation and intracoronary brachytherapy (ICBT). SES implantation for diffuse ISR was performed in 120 consecutive patients and their results were compared with those from 240 patients treated with beta-radiation with balloons filled with rhenium-188 and mercaptoacetyltriglycine. The radiation dose was 15 or 18 Gy at a depth of 1.0 mm into the vessel wall. The primary end point was 3-year major adverse cardiac events including myocardial infarction, cardiac death, and target lesion revascularization. The 2 groups were similar in baseline clinical and angiographic characteristics. Lesion lengths were 25.1 +/- 14.2 mm in the SES group and 24.5 +/- 10.4 mm in the ICBT group (p = 0.15). In-stent acute gain was greater in the SES group than in the ICBT group (2.23 +/- 0.62 vs 1.91 +/- 0.54 mm, p <0.001). We obtained 6-month angiographic follow-up in 287 patients (79.7%). In-segment angiographic restenoses were 7.4% (7 of 94) in the SES group and 26.4% (51 of 193) in the ICBT group (p <0.05). Two myocardial infarctions (1 in each group) and 5 deaths (4 in SES group, 1 in ICBT group) occurred during 3-year follow-up. At 3 years, survival rates without target lesion revascularization (94.1 +/- 2.2% vs 84.6 +/- 2.3%, p = 0.011) and major adverse cardiac events (92.5 +/- 2.4% vs 84.2 +/- 2.4%, respectively, p = 0.03) were higher in the SES than in the ICBT group. In conclusion, compared with ICBT, SES implantation for diffuse ISR is more effective in decreasing recurrent restenosis and improving long-term outcomes.

Incidence and predictors of late recurrence after beta-radiation therapy with a 188Re-MAG3-filled balloon for diffuse in-stent restenosis

BACKGROUND

The long-term fate of patent irradiated segments at 6 months after beta-radiation therapy has not been sufficiently evaluated.

METHODS

Two-year follow-up angiography was performed in 52 patients with patent irradiated segments at 6 months after beta-radiation with a rhenium 188-mercaptoacetyltriglycine-filled balloon for diffuse in-stent restenosis. We evaluated late recurrence (LR) and its predictors after beta-radiation.

RESULTS

Late recurrence at 2 years after radiation was observed in 10 (19.2%) of 52 patients. The minimal lumen diameter (MLD) progressively decreased, from 2.67 +/- 0.44 mm at postprocedure to 2.42 +/- 0.53 mm at 6 months to 2.09 +/- 0.75 mm at 2 years (P = .001). In the 42 patients without LR, the MLD decreased from postprocedure (2.74 +/- 0.43 mm) to 6 months (2.44 +/- 0.54 mm; P = .006), but did not change between 6 months and 2 years (2.35 +/- 0.49 mm, P = .13). In the LR group, the MLD was unchanged from postprocedure (2.33 +/- 0.29 mm) to 6 months (2.30 +/- 0.43 mm; P = .81), but decreased significantly between 6 months and 2 years (1.02 +/- 0.75 mm, P = .001). Multivariate analysis identified postprocedural MLD as an independent predictor of LR (odds ratio 0.025, 95% CI 0.007-0.94, P = .04). Late target lesion revascularization was performed in 6 patients (11.5%) between 6 months and 2 years after radiation.

CONCLUSION

Although LR after radiation was observed in some patients, irradiated segments remained stable for up to 2 years in most patients. Smaller postprocedural MLD, followed by delayed late loss between 6 months and 2 years, was associated with LR.

Peristent remodeling and neointimal suppression 2 years after polymer-based, paclitaxel-eluting stent implantation: insights from serial intravascular ultrasound analysis in the TAXUS II study

BACKGROUND

The purpose of this study was to evaluate long-term vascular responses as long as 2 years after implantation of polymer-based, paclitaxel-eluting stents in contrast to uncoated stents.

METHODS AND RESULTS

TAXUS II is a randomized, double-blind trial comparing slow-release (SR) and moderate-release (MR) TAXUS stents with bare-metal control stents (BMSs). One hundred sixty-one event-free patients (SR, 43; MR, 41; and BMS, 77) underwent serial intravascular ultrasound (IVUS) analysis after the procedure and at 6 months and 2 years. At 2 years, neointimal responses continued to be significantly suppressed in the SR and MR groups when compared with the BMS group (BMS, 1.49+/-1.12 mm2; SR, 0.94+/-0.76 mm2 [P=0.004]; and MR, 1.06+/-0.90 mm2 [P=0.02]). Between 6 months and 2 years, the BMS group showed compaction of the neointima (Delta, -0.22+/-1.05 mm2 [P=0.08]). In contrast, both the SR and MR groups exhibited an increase (Delta SR, 0.30+/-0.76 mm2 (P=0.01); MR, 0.41+/-0.94 mm2 [P=0.009]). Between 6 months and 2 years, the initial increase in plaque outside the stent regressed in the BMS and SR groups to levels comparable to those after the procedure, whereas expansive remodeling partially regressed in the MR group (Delta between after the procedure and 2 years BMS, -0.34+/-1.28 mm2 [P=0.05]; SR, -0.02+/-1.40 mm2 [P=0.93]; MR, 0.32+/-1.56 mm2 [P=0.27]).

CONCLUSIONS

The 2-year follow-up demonstrates that neointimal suppression was dose independent and that this effect was still sustained at 2 years. However, the increase in area outside the stent seen at 6 months regressed to different extents in a dose-dependent manner at 2 years.

Comparison of angiographic and clinical outcomes between rotational atherectomy and cutting balloon angioplasty followed by radiation therapy with a rhenium 188-mercaptoacetyltriglycine-filled balloon in the treatment of diffuse in-stent restenosis

BACKGROUND

Rotational atherectomy (RA) and cutting balloon angioplasty (CBA) have been shown to effectively dilate in-stent restenosis (ISR). It is not known, however, which of these technique, when followed by beta-radiation, is more effective. Therefore, we performed a prospective randomized study comparing RA and CBA before beta-radiation therapy for diffuse ISR.

METHODS

Patients with diffuse ISR were randomly assigned to receive RA (group 1, n = 58) or CBA (group 2, n = 55) before beta-radiation therapy with a rhenium 188-mercaptoacetyltriglycine-filled balloon, with the radiation dose being 18 Gy at a depth of 1.0 mm into the vessel wall. The primary end point was angiographic restenosis at 6 months, and the secondary end point was major adverse cardiac events (myocardial infarction, death, target lesion revascularization) at 9 months.

RESULTS

The 2 groups were similar in baseline characteristics. Mean lesion length was 21.0 +/- 11.2 mm in group 1 and 20.8 +/- 10.2 mm in group 2 (P = .77). Radiation was delivered successfully to all patients. We obtained 6-month angiographic follow-up in 90 patients (80%). The rates of angiographic restenosis were 14.9% (7 of 47) in group 1 and 14.0% (6 of 43) in group 2 (P = .89). No patient experienced myocardial infarction or death during the 9-month follow-up period. Rates of target lesion revascularization or major adverse cardiac events were 3.4% in group 1 and 3.6% in group 2 (P = .94) during the 9-month follow-up.

CONCLUSIONS

Either RA or CBA, followed by beta-radiation using a rhenium 188-mercaptoacetyltriglycine-filled balloon, is equally safe and effective for diffuse ISR in 6-month angiographic and 9-month clinical outcomes.

Long term outcome after intracoronary beta radiation therapy

OBJECTIVES

To determine the long term outcome after intracoronary beta radiation therapy (IRT).

SETTING

Tertiary referral centre.

METHODS

The rate of major adverse cardiac events (MACE) was retrospectively determined in 301 consecutive patients who were treated with IRT. MACE was defined as death, myocardial infarction, or any reintervention. Long term clinical outcome was obtained from an electronic database of hospital records and from questionnaires to the patients and referring physicians. Long term survival status was assessed by written inquiries to the municipal civil registries.

RESULTS

The mean (SD) follow up was 3.6 (1.2) years. The cumulative incidence of MACE at six months was 19.1%, at one year 36.4%, and at four years 58.3%. The target lesion revascularisation (TLR) rate at six months was 12.9%, at one year 28.3%, and at four years 50.4%. From multivariate analysis, dose < 18 Gy was the most significant predictor of TLR. At four years the cumulative incidence of death was 3.8%, of myocardial infarction 13.4%, and of coronary artery bypass surgery 11.3%. Total vessel occlusion was documented in 12.3% of the patients.

CONCLUSIONS

In the long term follow up of patients after IRT, there are increased adverse cardiac events beyond the first six months.

Cardiovascular effects of radiation therapy: practical approach to radiation therapy-induced heart disease

Radiation induced heart diseases (RIHD) are increasingly recognized as more patients who received radiation therapy survive their diseases with improved management of various malignancies. Radiation affects every component of the heart, ranging from subclinical histopathologic changes to overt clinical disease. Pericardial involvement is the most common and includes asymptomatic pericardial effusion and constrictive pericarditis. The diseases involving the myocardium, valvular apparatus, and conduction system are often subclinical. When symptomatic, they are often the harbinger of more lethal, but treatable, radiation-induced coronary artery disease (CAD). Improvements in the modern radiation delivery systems have minimized irradiation of the heart. However, with increased and emerging indications for radiation therapy for various malignancies in the chest, as a part of bone marrow transplantations, and as the main agent of brachytherapy for advanced preexisting CAD, the incidence of RIHD is likely to increase. Appropriate management of RIHD, either overt or occult, must include understanding the natural history of RIHD, recognition of symptoms by careful history, and vigilant search for treatable causes of the RIHD or other diseases that might mimic RIHD. This article focuses on providing practical yet comprehensive clinical information for general internal medicine and cardiology practices.

Two-year clinical follow-up of 90Sr/90 Y beta-radiation versus placebo control for the treatment of in-stent restenosis

BACKGROUND

It is an ongoing concern that intracoronary brachytherapy may possibly just delay the problem of in-stent restenosis ("late catch up"). For gamma-radiation, 3 placebo-controlled studies have shown the maintenance of the initially positive effect after 2 years, but similar data do not exist for beta-radiation. STents And Restenosis Trial (START) was the first placebo-controlled randomized trial for in-stent restenosis with beta-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 -9.2 [-17.5-0.8]). 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% +/- 3.8% to 71.6% +/- 3.3% (P = .027) and freedom from MACE from 58.9% +/- 3.7% to 68.0% +/- 3.4% (P = .035).

CONCLUSIONS

The START trial shows for the first time that the initial beneficial effects of intracoronary brachytherapy with beta-radiation using 90 Sr/ 90 Y are maintained at 2-year clinical follow-up period.

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.

Emergency localization of radioactive seeds lost during intracoronary brachytherapy

Recently, it has been reported that brachytherapy catheters ruptured in vivo. Localization of lost beta-radiation-emitting seeds is a problem because no appropriate technique is available that is rapid and precise. We developed a technique to localize beta-emitting seeds utilizing the effect that beta-radiation induces bremsstrahlung. The loss of a single radioactive source was simulated in an Alderson Phantom representing a human body. The beta-induced bremsstrahlung could be detected selectively by a gamma-camera. The position of the radioactive seed could be located within 5 min with an accuracy of +/- 0.5 cm. The result of this study suggests that in an emergency case of loss of a brachytherapy source, a commercially available gamma-camera can be a valuable tool to detect lost beta-radiation-emitting seeds rapidly and precisely. In addition, the technique minimizes the patient's as well as the surgeon's exposure to radiation and reduces the extent of surgical trauma.

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 beta-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 beta-irradiation of in-stent restenotic lesions is not complete within 6 months but is sustained with a gradual decrease over 24 months.

Coronary artery pseudoaneurysm after balloon angioplasty and intracoronary ?-radiation for in-stent restenosis

Intracoronary brachytherapy is an effective method for treating in-stent restenosis. We report a case of coronary artery pseudoaneurysm after balloon angioplasty and intracoronary beta-radiation. The pseudoaneurysm was treated successfully with implantation of two coronary stent grafts.