Low-molecular weight heparin versus aspirin and dipyridamole after femoropopliteal bypass grafting.
Low-molecular weight heparin has theoretical advantages over aspirin and dipyridamole in maintaining vascular-graft patency by virtue of its better antithrombotic effect and antiproliferative activity on vascular, smooth-muscle cells. We tested the hypothesis that low-molecular weight heparin would be more effective than aspirin and dipyridamole in maintaining graft patency in patients undergoing femoropopliteal bypass grafting. Patients were randomised to receive either a daily injection of 2500 IU low-molecular weight heparin, or 300 mg aspirin with 100 mg dipyridamole 8 hourly for 3 months. 94 patients were randomised to low-molecular weight heparin and 106 to aspirin and dipyridamole. Patients were stratified according to indication for surgery and were followed up for 1 year. Kaplan-Meier estimate of graft patency showed 87% graft survival on low-molecular-weight heparin and 72% on aspirin and dipyridamole at 6 months. At 12 months, the respective figures were 78% and 64%. Stratified survival analysis showed that this benefit was confined to those having salvage surgery (log rank test p = 0.0006); for those having surgery for claudication there was no significant benefit. No major bleeding events occurred in either group. We conclude that low-molecular weight heparin is better than aspirin and dipyridamole in maintaining femoropopliteal-graft patency in patients with critical limb ischaemia undergoing salvage surgery. This treatment should have considerable cost benefits.
Edmondson
R A
RA
Thrombosis Research Institute, London, UK.
Cohen
A T
AT
Das
S K
SK
Wagner
M B
MB
Kakkar
V V
VV
D000328:Adult; D000368:Aged; D001241:Aspirin / Q000627:therapeutic use*; D004176:Dipyridamole / Q000627:therapeutic use*; D004359:Drug Therapy, Combination; D005260:Female; D005263:Femoral Artery / Q000601:surgery; D006083:Graft Occlusion, Vascular / Q000517:prevention & control*; D006495:Heparin, Low-Molecular-Weight / Q000627:therapeutic use*; D006801:Humans; D008297:Male; D008875:Middle Aged; D016491:Peripheral Vascular Diseases / Q000601:surgery*; D011150:Popliteal Artery / Q000601:surgery; D011183:Postoperative Complications; D016016:Proportional Hazards Models; D011446:Prospective Studies; D016019:Survival Analysis; D014654:Vascular Patency / Q000187:drug effects
D006495:Heparin, Low-Molecular-Weight; D004176:Dipyridamole; D001241:Aspirin