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73rd Scientific Sessions American Heart Association, November 2000, New Orleans, Lousiana
- The Edge Effect: The Impact of Vessel Injury and Dose Fall-Off after Treatment of In-Stent Restenosis with SR-90 Radiation. Results from the START Trial.
- A. J. Lansky (1), R. Mehran (1), I. R. Crocker (2), B. Speiser (3), P. Teirstein (4), T. A. Bass (5), S. Silber (6), B. D. Rutherford (7), D. A. Cox (8), W. K. Laskey (9), R. E. Kuntz (10), R. Bonan (11)
- 1, Lenox Hill Hosp, New York, NY
- 2, Emory Univ, Atlanta, GA
- 3, St Joseph's Hosp and Medical Ctr, Phoenix, AZ
- 4, Scripps Clin, La Jolla, CA
- 5, Univ of Florida, Jacksonville, FL
- 6, Dr Mueller Hosp, Munich Germany
- 7, St Luke's Hosp, Kansas City, MO
- 8, Mid Carolina Cardiology, Charlotte, NC
- 9,Univ of Maryland, Baltimore, MD
- 10, Brigham and Women's Hosp, Boston, MA
- 11, Montreal Heart Inst, Montreal Canada
- Circulation, 102: II-669 (2000)
To assess the mechanisms of "edge effect" in START, we measured the diameter stenosis(%DS)in the dose fall off zones (edges) defined as ±5mm on either side of the radiation wire markers in 390 pts with angiographic follow-up. Compared to placebo, pts treated with SR-90 tended to have a higher %DS in the proximal edge (25.3% vs 20.7%,p=0.073)and distal edge (20.4% vs 16.5%, p=0.087). Geographic miss (GM) defined as injury in the dose fall-off zones was frequent(75%), and was not associated with an increase in DS with Sr-90 compared to placebo. Among pts with restenosis (N=144), Sr-90 pts had more edge RS and a higher edge %DS compared to placebo (Table). RS was lower with no GM for both placebo and Sr-90 (<18%) compared to pts with GM (>81%), however there were no differences between treatment groups. We conclude:(1) overall Sr-90 is associated with a mild edge effect, (2) RS localized to the dose fall-off zone is 50% more frequent with SR-90, (3) due to the high prevalence of GM (75%), its contribution to the edge effect remains unanswered. The longer radiation margins in the START40/20 Trial will provide further insight.
All Patients with RS, RS rates are not additive
Placebo Sr-90 p-Value Stent RS 90.6% 48.2% < 0.0001 Prox Edge RS 21.2% 45.8% 0.0017 Distal Edge RS 12.9% 25.4% 0.055 Both Edges RS 4.7% 10.2% 0.2047 Any Edge RS 29.4% 61.0% 0.0002 %DS Prox 28.0+/-29.7 46.8+/-32.4 0.0009 %DS Distal 23.2+/-27.7 31.7+/-29.3 0.0908
