phosphorus-radioisotopes and Coronary-Artery-Disease

Radioactive stents with an activity of 0.75 to 12 microCi have shown >40% edge restenosis due to neointimal hyperplasia and negative remodeling. This trial evaluated whether radioactive Cold Ends stents might resolve edge restenosis by preventing remodeling at the injured extremities.. The 25-mm long (15-mm radioactive center and 5-mm nonradioactive ends) Cold Ends stents had an activity of 3 to 12 microCi at implantation. Forty-three stents were implanted in 43 patients with de novo native coronary artery disease. Two procedural, 1 subacute, and 1 late stent thrombosis occurred. A restenosis rate of 22% was observed with a shift of the restenosis, usually occurring at the stent edges of radioactive stents, into the Cold Ends stents. The most severe restenosis occurred at the transition zone from radioactive to nonradioactive segments, a region located in dose fall-off.. Cold Ends stents did not resolve edge restenosis.

Topics: Adult; Aged; Aged, 80 and over; Angina Pectoris; Blood Vessel Prosthesis Implantation; Brachytherapy; Coronary Angiography; Coronary Artery Disease; Coronary Thrombosis; Dose-Response Relationship, Radiation; Female; Fibrinolytic Agents; Follow-Up Studies; Graft Occlusion, Vascular; Humans; Male; Middle Aged; Phosphorus Radioisotopes; Platelet Aggregation Inhibitors; Stents; Treatment Outcome

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.

Topics: Angioplasty, Balloon, Coronary; Brachytherapy; Case-Control Studies; Chi-Square Distribution; Coronary Artery Disease; Disease-Free Survival; Follow-Up Studies; Humans; Kaplan-Meier Estimate; Logistic Models; Myocardial Infarction; Netherlands; Phosphorus Radioisotopes; Propensity Score; Proportional Hazards Models; Prospective Studies; Risk Assessment; Risk Factors; Strontium Radioisotopes; Survival Rate; Time Factors; Treatment Outcome; Yttrium Radioisotopes

This article investigates the dosimetry of a radioactive stent and radioactive liquid balloon placed into the heart vasculature to prevent restenosis after atherosclerosis treatment. The research aims to know the dosages to establish a suitable activity which achieves restenosis control and thereafter minimize radiation effects in the cardiac muscle. In order to accomplish the dosimetric analysis, a heart voxel model was assembled based on tomographic images. The computational model consists of a three-dimensional matrix taken from 60 tomographic images representing the major heart tissues. A radioactive ¹⁵³Sm liquid balloon is simulated as well as a ³²P radioactive stent, inserted in an arbitrary heart artery. After simulation processing, the absorbed dose rate was evaluated in the heart musculature. The models are presented in two- and three-dimensional previews and the dosage profiles are shown by isodose curves superimposed onto the heart model.

Topics: Angioplasty; Brachytherapy; Computer Simulation; Coronary Angiography; Coronary Artery Disease; Coronary Restenosis; Humans; Imaging, Three-Dimensional; Models, Cardiovascular; Phosphorus Radioisotopes; Prosthesis Design; Radiation Dosage; Radiation Injuries; Radiographic Image Interpretation, Computer-Assisted; Radioisotopes; Radiotherapy, Computer-Assisted; Samarium; Stents; Tomography, X-Ray Computed

The intracoronary changes that occur after brachytherapy for in-stent restenosis (ISR) have yet to be fully established. The purpose of this study in patients who had ISR was to examine the serial angioscopic changes in intracoronary lesions that occurred after brachytherapy. Forty-four patients who had ISR (49 lesions) underwent balloon angioplasty (n = 34) or directional atherectomy (n = 15), followed by intracoronary brachytherapy using a beta-emitting phosphorus-32 source wire. Angioscopic investigations were performed 3 and 9 months after brachytherapy. Uncovered stents were detected in 63.3% of lesions at 3 months. A significant decrease (p = 0.028) in this prevalence occurred over the next 6 months, with 36% of lesions having uncovered stents at 9 months. At 3 months, 33% of the lesions had visible erosion or ulceration and superficial thrombus. The prevalence of these characteristics was decreased at 9 months, although 17% of the lesions were still ulcerated or eroded at that time. Protruding thrombus was not observed in any lesion at 3 and 9 months. In conclusion, uncovered stents and intimal erosions or ulcerations were still present 9 months after brachytherapy in 36% and 17% of lesions, respectively. These results suggest that the healing process was not completed 9 months after brachytherapy in approximately 33% of lesions.

Topics: Aged; Angioplasty, Balloon; Angioscopy; Atherectomy, Coronary; Brachytherapy; Coronary Artery Disease; Coronary Restenosis; Coronary Thrombosis; Female; Follow-Up Studies; Humans; Male; Phosphorus Radioisotopes; Stents; Tunica Intima

We report a case of obstructive in-stent restenosis in a diffusely diseased saphenous vein graft complicated by a non-ST-elevation myocardial infarction. With tirofiban infusion, the extensively occluded saphenous bypass was reperfused, establishing a TIMI flow 3, and then entirely irradiated with a beta source (32P) without any complication. At 7 months the patient was asymptomatic and the control angiogram did not reveal any restenosis. In conclusion, 32P beta brachytherapy may be extremely effective not only in case of native vessel in-stent restenosis but also in cases of high-risk vein graft in-stent restenosis.

Topics: Aged; Angioplasty, Balloon, Coronary; Aspirin; Beta Particles; Blood Vessel Prosthesis; Brachytherapy; Coronary Angiography; Coronary Artery Bypass; Coronary Artery Disease; Female; Fibrinolytic Agents; Graft Occlusion, Vascular; Humans; Myocardial Infarction; Phosphorus Radioisotopes; Reoperation; Saphenous Vein; Stents; Ticlopidine; Tirofiban; Tyrosine

Experimental studies have demonstrated that 32P radioactive stents reduce neointimal formation at 28 days in porcine iliac and coronary arteries. Our objective was to determine the long-term dose-response effects of 1.0- to 12.0-microCi 32P radioactive stents in a porcine atherosclerotic coronary model.. Control (n=19) and 1.0- to 12.0-microCi 32P radioactive (n=43) stents (total, n=62) were implanted in the coronary arteries of 31 miniature swine at 28 days after creation of a fibrocellular plaque by overstretch balloon injury and cholesterol feeding. Angiography and histomorphometry were performed at 6 months. Stent thrombosis occurred in 3 radioactive (7.7%) and no control stents (P=0.54). On histology, the mean neointimal area and the percent in-stent stenosis correlated positively with increasing stent activity (r=0.64, P<0.001). The mean neointimal area (mm2) for the stents with >/=3.0 microCi 32P (3.57+/-1.21) was significantly greater than that for the nonradioactive stents (1.78+/-0.68, P<0.0001). The neointima of the stents with >/=3.0 microCi 32P was composed of smooth muscle cells, matrix proteoglycans, calcification, foam cells, and cholesterol clefts.. Continuous low-dose-rate irradiation delivered by high-activity (32)P radioactive stents promotes the formation of an "atheromatous" neointima after 6 months in this experimental model. These data may be useful for predicting late tissue responses to radioactive stents in human coronary arteries.

Topics: Animals; Coronary Angiography; Coronary Artery Disease; Coronary Thrombosis; Coronary Vessels; Dose-Response Relationship, Radiation; Muscle, Smooth, Vascular; Phosphorus Radioisotopes; Stents; Swine; Swine, Miniature

Topics: Angioplasty, Balloon, Coronary; Animals; Coronary Artery Disease; Coronary Vessels; Equipment Design; Heparin; Humans; Phosphorus Radioisotopes; Rabbits; Recurrence; Stents; Swine; Technology Assessment, Biomedical; Thrombosis