Intravascular gamma radiation for in-stent restenosis in saphenous-vein bypass grafts.
BACKGROUND
Intracoronary radiation therapy is effective in reducing the recurrence of in-stent stenosis in native coronary arteries. We examined the effects of intravascular gamma radiation in patients with in-stent restenosis of saphenous-vein bypass grafts.


METHODS
A total of 120 patients with in-stent restenosis in saphenous-vein grafts, the majority of whom had diffuse lesions, underwent balloon angioplasty, atherectomy, additional stenting, or a combination of these procedures. If the intervention was successful, the patients were randomly assigned in a double-blind fashion to intravascular treatment with a ribbon containing either iridium-192 or nonradioactive seeds. The prescribed dose, delivered at a distance of 2 mm from the source, was 14 to 15 Gy in vessels that were 2.5 to 4.0 mm in diameter and 18 Gy in vessels with a diameter that exceeded 4.0 mm. The primary end points were death from cardiac causes, Q-wave myocardial infarction, revascularization of the target vessel, and a composite of these events at 12 months.


RESULTS
Revascularization and radiation therapy were successfully accomplished in all patients. At six months, the restenosis rate was lower in the 60 patients assigned to the iridium-192 group than in the 60 assigned to the placebo group (21 percent vs. 44 percent, P=0.005). At 12 months, the rate of revascularization of the target lesion was 70 percent lower in the iridium-192 group than in the placebo group (17 percent vs. 57 percent, P<0.001), and the rate of major cardiac events was 49 percent lower (32 percent vs. 63 percent, P<0.001).


CONCLUSIONS
The results of our study support the use of gamma-radiation therapy for the treatment of in-stent restenosis in patients with bypass grafts.
Waksman
Ron
R
Division of Cardiology, Washington Hospital Center and the Washington Cancer Institute, Washington, DC 20010, USA. ron.waksman@medstar.net
Ajani
Andrew E
AE
White
R Larry
RL
Chan
Rosanna C
RC
Satler
Lowell F
LF
Kent
Kenneth M
KM
Pichard
Augusto D
AD
Pinnow
Ellen E
EE
Bui
Anh B
AB
Ramee
Steven
S
Teirstein
Paul
P
Lindsay
Joseph
J
D000368:Aged; D000787:Angina Pectoris / Q000628:therapy; D015906:Angioplasty, Balloon, Coronary; D017073:Atherectomy; D001918:Brachytherapy; D017023:Coronary Angiography; D001026:Coronary Artery Bypass; D003327:Coronary Disease / Q000401:mortality / Q000601:surgery; D023903:Coronary Restenosis / Q000532:radiotherapy* / Q000601:surgery / Q000628:therapy; D018572:Disease-Free Survival; D004311:Double-Blind Method; D005260:Female; D005720:Gamma Rays / Q000627:therapeutic use*; D006801:Humans; D007496:Iridium Radioisotopes / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D012501:Saphenous Vein / Q000637:transplantation; D015607:Stents
D007496:Iridium Radioisotopes