Introduction: Aspirin usage before coronary artery bypass graft (CABG) surgery is associated with a lower risk of postoperative in-hospital mortality and appears to be safe (1). The aim of this study is to evaluate the biological effect of aspirin in these conditions. We evaluated thromboxane A2 synthesis, indirect markers of platelet activation levels and inflammatory process in aspirin treated patients undergoing CABG surgery.

Methods: Twenty aspirin treated (160 mg/day) patients were enrolled prospectively. We evaluated the association between aspirin usage for more than 1 month and urine 11-dehydro thromboxane B2 (11DHTB2) level, as well as soluble P-Selectin (sPsel) and soluble CD40 ligand (sCD40L) serum levels during the 7 days following surgery. Considering the variation of platelet count following CABG surgery and the known relation between sCD40L level and platelet mass (2), we reported sPsel and sCD40L serum levels to the platelet count. Blood and urine samples were collected at H0 (before surgery) and at H36, 72, 168 post surgery. Inflammatory process was also investigated by C-reactive protein and fibrinogen level determinations.

Results: Main data are expressed in table 1. 11DHTB2 (metabolite of thromboxane A2) increased at H36 following surgery and decreased progressively until day 7 without reaching the preoperative level. 11DHTB2 didn’t correlate with the inflammatory process (C-reactive protein and fibrinogen levels). Only concomitant increase of leukocytes count and 11DHTB2 level was observed. In the other hand, at H36 post surgery, sPsel and sCD40L levels slightly increased. Soluble P-selectin level progressively decreased until H168 while sCD40L level remain stable up to H168. At least, no correlation was found between sPsel, sCD40L and 11DHTB2.

Conclusion: These data indicated that, under aspirin treatment, a slight and transitional platelet activation occurred after CABG surgery. According to the lake of correlation between sPsel, sCD40L levels and 11DHTB2 level, we hypothesized that 11DHTB2 is produced by an another source (i.e leukocytes) which occurred independently to platelet activation.

Biological data.

H0 (n = 20)H36 (n = 20)H72 (n = 20)H168 (n = 20)
All data are expressed as mean ± 1SD. 11DHTB2: 11-dehydro thromboxane B2; sCD40L: soluble CD40 ligand. 
Platelet count (109/L) 247 ± 46 176 ± 49 175 ± 59 319 ± 89 
Leukocytes count (109/L) 8.1 ± 3.1 12.5 ± 2.9 9.8 ± 4.1 9.7 ± 3.8 
C-reactive protein (mg/L) 11.5 ± 20.4 113.1 ± 80 207 ± 94 87 ± 93.3 
Fibrinogen (g/L) 4.2 ± 1.2 4.4 ± 1.4 7.8 ± 1.6 8.5 ± 1.9 
11DHTB2 (ng/mmol creatinin) 24.5 ± 21.1 104.8 ± 36.8 42.5 ± 31.7 33.9 ± 42.7 
sCD40L (ng/108 platelets) 2.3 ± 1 3.3 ± 1.1 3.5 ± 1 3.3 ± 0.9 
sP-selectin (ng/108 platelets) 55 ± 34 99 ± 64 81 ± 48 59 ± 27 
H0 (n = 20)H36 (n = 20)H72 (n = 20)H168 (n = 20)
All data are expressed as mean ± 1SD. 11DHTB2: 11-dehydro thromboxane B2; sCD40L: soluble CD40 ligand. 
Platelet count (109/L) 247 ± 46 176 ± 49 175 ± 59 319 ± 89 
Leukocytes count (109/L) 8.1 ± 3.1 12.5 ± 2.9 9.8 ± 4.1 9.7 ± 3.8 
C-reactive protein (mg/L) 11.5 ± 20.4 113.1 ± 80 207 ± 94 87 ± 93.3 
Fibrinogen (g/L) 4.2 ± 1.2 4.4 ± 1.4 7.8 ± 1.6 8.5 ± 1.9 
11DHTB2 (ng/mmol creatinin) 24.5 ± 21.1 104.8 ± 36.8 42.5 ± 31.7 33.9 ± 42.7 
sCD40L (ng/108 platelets) 2.3 ± 1 3.3 ± 1.1 3.5 ± 1 3.3 ± 0.9 
sP-selectin (ng/108 platelets) 55 ± 34 99 ± 64 81 ± 48 59 ± 27 
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Topics:
aspirin, coronary artery bypass surgery, platelet activation, thromboxane, surgical procedures, operative, c-reactive protein, cd40 ligand, fibrinogen assay, p-selectin, fibrinogen
1)
Bybee KA, Powell BD, Valeti U, Rosales AG, Kopecky SL, Mullany C, Wright RS. Preoperative aspirin therapy is associated with improved postoperative outcomes in patients undergoing coronary artery bypass grafting.
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Viallard JF, Solanilla A, Gauthier B, Contin C, Déchanet J, Grosset C, Moreau JF, Praloran V, Nurden P, Pellegrin JL, Nurden AT, Ripoche J. Increased soluble and platelet-associated CD40ligand in essential thrombocythemia and reactive thrombocytosis.
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Author notes

Disclosure: No relevant conflicts of interest to declare.

2007, The American Society of Hematology
2007
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