Aspirin usage and its influence on femoro-popliteal vein graft patency. The Femoro-popliteal Bypass Trial Participants.
As part of the Femoro-popliteal Bypass Trial patients undergoing femoro-popliteal vein bypass were randomised to aspirin 300 mg and dipyridamole 150 mg twice daily or identical placebo tablets. Blood was taken from a subgroup of 145 patients (mean age 66.3 years) with patent grafts at 6 months. Serum salicylate analysis revealed that of the 65 randomised to receive placebo 18 (28%) had evidence of salicylate in their sample (greater than 50 ng ml-1). Similarly, in those randomised to active treatment and considered to be good compliers 16/61 (26%) had no evidence of salicylate in their serum sample (less than 50 ng ml-1). Analysis of primary graft patency by "intention to treat" failed to detect a difference by life table, the risk being slightly higher in the group assigned to placebo (RR = 1.33, 95% confidence internal C.I. 0.64-2.78, p = 0.438). When comparing patients with no detectable serum concentration (less than 50 ng ml-1) with patients with serum salicylate over 50 ng ml-1 there was a significant difference in graft patency at 66 versus 83% respectively at 3 years (RR = 2.38, 95%C.I. 1.08-5.26, p = 0.024). When corrected for a number of possible risk factors this significant difference was maintained (RR = 2.78, 95%C.I. 1.15-6.67, p = 0.017). Although these findings are based on observational data they provide indirect evidence of an improvement in graft patency with aspirin. This result combined with the finding of a significant reduction in cardiovascular events in the main trial results support the use of aspirin and dipyridamole in patients undergoing femoro-popliteal vein bypass.
Franks
P J
PJ
Department of Surgery, Charing Cross and Westminster Medical School, London, U.K.
Sian
M
M
Kenchington
G F
GF
Alexander
C E
CE
Powell
J T
JT
D000368:Aged; D000714:Anastomosis, Surgical; D001241:Aspirin / Q000008:administration & dosage / Q000097:blood / Q000494:pharmacology*; D004311:Double-Blind Method; D005260:Female; D005268:Femoral Vein / Q000187:drug effects / Q000601:surgery*; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D010349:Patient Compliance; D011152:Popliteal Vein / Q000187:drug effects / Q000601:surgery*; D014654:Vascular Patency / Q000187:drug effects*
D001241:Aspirin