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Stent + Radiation No Sure Cure for Stenosis

Stent + Radiation No Sure Cure for Stenosis Orlando, Fla—Radiation therapy cannot be recommended to prevent restenosis caused in patients undergoing coronary angioplasty or stenting for de novo lesions, Richard E. Kuntz, MD, told participants in the American College of Cardiology's Annual Scientific Session. Kuntz, lead investigator of the Beta-Cath System Trial, is with the Division of Clinical Biometrics at Brigham and Women's Hospital in Boston. Kuntz said he was surprised at the outcome of the study and hypothesized that the negative results were caused by poor radiation and stenting procedures—and not by some basic flaw in the theory of radiation's benefits. Results disappointing Starting in 1997, the Beta-Cath System Trial randomized 1455 patients with single de novo lesions into two groups that received β-radiation with Sr-90 or placebo following percutaneous transluminal coronary angioplasty (PTCA). The study was funded by Novoste Corp, which manufactures the Beta-Cath device. At 8 months following the procedure, β-radiation significantly reduced the rate of restenosis within the lesion segment, to 21.4% in the treatment group vs 34.3% restenosis in the placebo group. But when investigators studied the analysis segment—the lesion plus its edges, including the area of balloon injury and 5 mm on each side—they found increased restenosis at the edges. They concluded that the procedure did not significantly reduce restenosis, which occurred in 36% of the placebo group vs 31% of the radiation group. Kuntz speculated that the radiation had damaged the tissue, causing the blood vessel to try to heal itself and thereby producing scar tissue that obstructed the artery. After analyzing various study cohorts, Kuntz found that 8 months after radiation restenosis had increased by 27% in patients with de novo lesions who had angiographic restenosis following PTCA, β-radiation, stenting, and prolonged antiplatelet therapy. When analysis segments were studied in these patients, restenosis was found in 35.3% of the placebo group and 44.9% of the radiation group. Improvement possible Kuntz said he believes a trial of radiation therapy following stenting might yield positive results if improved techniques were used. "We're dealing with something that does something good," he said. "We're also dealing with something that causes some injury, and we want to figure out if we can understand the phenomenon and correct it, or find out it's just not correctible." Kuntz suggested that in a new trial, investigators might improve their success rate if they were to use direct stenting with no predilation, use a single stent with "short shoulders" to minimize epithelial injury, and use more radiation seeds to bracket the site and place them in the site after, instead of before, placing the stent. http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png JAMA American Medical Association

Stent + Radiation No Sure Cure for Stenosis

JAMA , Volume 285 (16) – Apr 25, 2001

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Publisher
American Medical Association
Copyright
Copyright © 2001 American Medical Association. All Rights Reserved.
ISSN
0098-7484
eISSN
1538-3598
DOI
10.1001/jama.285.16.2069-JMN0425-4-1
Publisher site
See Article on Publisher Site

Abstract

Orlando, Fla—Radiation therapy cannot be recommended to prevent restenosis caused in patients undergoing coronary angioplasty or stenting for de novo lesions, Richard E. Kuntz, MD, told participants in the American College of Cardiology's Annual Scientific Session. Kuntz, lead investigator of the Beta-Cath System Trial, is with the Division of Clinical Biometrics at Brigham and Women's Hospital in Boston. Kuntz said he was surprised at the outcome of the study and hypothesized that the negative results were caused by poor radiation and stenting procedures—and not by some basic flaw in the theory of radiation's benefits. Results disappointing Starting in 1997, the Beta-Cath System Trial randomized 1455 patients with single de novo lesions into two groups that received β-radiation with Sr-90 or placebo following percutaneous transluminal coronary angioplasty (PTCA). The study was funded by Novoste Corp, which manufactures the Beta-Cath device. At 8 months following the procedure, β-radiation significantly reduced the rate of restenosis within the lesion segment, to 21.4% in the treatment group vs 34.3% restenosis in the placebo group. But when investigators studied the analysis segment—the lesion plus its edges, including the area of balloon injury and 5 mm on each side—they found increased restenosis at the edges. They concluded that the procedure did not significantly reduce restenosis, which occurred in 36% of the placebo group vs 31% of the radiation group. Kuntz speculated that the radiation had damaged the tissue, causing the blood vessel to try to heal itself and thereby producing scar tissue that obstructed the artery. After analyzing various study cohorts, Kuntz found that 8 months after radiation restenosis had increased by 27% in patients with de novo lesions who had angiographic restenosis following PTCA, β-radiation, stenting, and prolonged antiplatelet therapy. When analysis segments were studied in these patients, restenosis was found in 35.3% of the placebo group and 44.9% of the radiation group. Improvement possible Kuntz said he believes a trial of radiation therapy following stenting might yield positive results if improved techniques were used. "We're dealing with something that does something good," he said. "We're also dealing with something that causes some injury, and we want to figure out if we can understand the phenomenon and correct it, or find out it's just not correctible." Kuntz suggested that in a new trial, investigators might improve their success rate if they were to use direct stenting with no predilation, use a single stent with "short shoulders" to minimize epithelial injury, and use more radiation seeds to bracket the site and place them in the site after, instead of before, placing the stent.

Journal

JAMAAmerican Medical Association

Published: Apr 25, 2001

Keywords: stents,constriction, pathologic

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