Twelve versus six months of clopidogrel to reduce major cardiac events in patients undergoing gamma-radiation therapy for in-stent restenosis: Washington Radiation for In-Stent restenosis Trial (WRIST) 12 versus WRIST PLUS.
BACKGROUND
Intracoronary gamma-radiation reduces recurrent in-stent restenosis (ISR). Late thrombosis was attenuated with 6 months of aspirin and clopidogrel. We aimed to find out whether 12 months of aspirin plus clopidogrel is superior to a strategy of 6 months after radiation therapy for patients with ISR.


RESULTS
One hundred twenty consecutive patients with diffuse ISR in native coronaries and vein grafts with lesions <80 mm in length underwent PTCA, laser ablation, or rotational atherectomy. Additional stents were placed in 39 patients (33%). After the intervention, a ribbon with different trains of radioactive 192Ir seeds was positioned to cover the treated site, and a dose of 14 Gy to 2 mm was prescribed. Patients were discharged with clopidogrel and aspirin for 12 months and followed up clinically. The cardiac clinical event rates at 15 months were compared with the gamma-treated (n=120) patients of the WRIST PLUS study (only 6 months of antiplatelet therapy). Whereas the late thrombosis rates were similar (3.3% for the group given 12 months of antiplatelet therapy versus 4.2% for the group given 6 months, P=0.72), the group treated with 12 months of antiplatelet therapy had a rate of 21% for major adverse cardiac events and 20% for target-lesion revascularization compared with 36% (P=0.01) and 35% (P=0.009), respectively, in patients who were treated with only 6 months of clopidogrel.


CONCLUSIONS
Twelve months of clopidogrel is superior to 6 months in reducing overall major cardiac events and revascularization rates at 15 months for patients with ISR treated with gamma-radiation. At least 12 months of clopidogrel therapy should be recommended for patients undergoing radiation therapy for ISR.
Waksman
Ron
R
Division of Cardiology, Washington Hospital Center, Washington, DC 20010, USA. ron.waksman@medstar.net
Ajani
Andrew E
AE
Pinnow
Ellen
E
Cheneau
Edouard
E
Leborgne
Laurent
L
Dieble
Regina
R
Bui
Anh B
AB
Satler
Lowell F
LF
Pichard
Augusto D
AD
Kent
Kenneth K
KK
Lindsay
Joseph
J
D001241:Aspirin / Q000627:therapeutic use; D001918:Brachytherapy; D000077144:Clopidogrel; D023903:Coronary Restenosis / Q000517:prevention & control / Q000628:therapy*; D004334:Drug Administration Schedule; D005260:Female; D005720:Gamma Rays; D006083:Graft Occlusion, Vascular / Q000532:radiotherapy; D006331:Heart Diseases / Q000517:prevention & control*; D006801:Humans; D007496:Iridium Radioisotopes / Q000627:therapeutic use; D008297:Male; D008875:Middle Aged; D010975:Platelet Aggregation Inhibitors / Q000627:therapeutic use*; D011446:Prospective Studies; D012042:Registries; D012306:Risk; D015607:Stents / Q000009:adverse effects; D013988:Ticlopidine / Q000031:analogs & derivatives / Q000627:therapeutic use*; D013995:Time; D016896:Treatment Outcome
D007496:Iridium Radioisotopes; D010975:Platelet Aggregation Inhibitors; D000077144:Clopidogrel; D013988:Ticlopidine; D001241:Aspirin