Activation of the coagulation system during coronary artery bypass grafting: comparison between on-pump and off-pump techniques.
OBJECTIVE
The activation of the coagulation and fibrinolytic systems and platelet function in patients undergoing coronary artery bypass surgery on-pump or off-pump techniques was compared.


METHODS
Thirty-two patients were randomly assigned to on-pump or off-pump coronary artery bypass grafting. Heparin was given at the same dose. Activation of the coagulation and fibrinolytic systems was evaluated by measurement of several markers. Platelet function was evaluated by in vitro bleeding time test. Blood samples were collected at 7 different times, up to postoperative day 6.


RESULTS
Overall tissue factor production was similar in the two groups. Thrombin formation was more elevated in the on-pump group (P < .001), particularly during the operation; prothrombin fragment 1.2 discharge values were higher than the preoperative ones (P = .002). Levels of tissue-plasminogen activator showed no difference between the groups (P = .1). D-dimers release was higher in the on-pump group (P = .0002). In vitro bleeding time was longer in the on-pump group (P < .0001), particularly in the first 24 hours; it was not prolonged in the off-pump group. In both groups, regardless of aspirin treatment, discharge in vitro bleeding times were lower than the preoperative ones (P < .01).


CONCLUSIONS
Although the extrinsic coagulation pathway is similarly activated, thrombin formation is more pronounced in patients having on-pump bypass grafting. Patients subjected to off-pump bypass grafting have normally functioning platelets and a weak activation of the fibrinolytic system. At discharge, both groups have preserved platelet function and increased thrombin formation. Further studies with angiographic evaluation are needed to establish a correlation between coagulation parameters, platelet function, and graft patency.
Paparella
Domenico
D
Division of Cardiac Surgery, Dipartimento d'Emergenza e Trapianti di Organo, University of Bari, Italy. paparella@tin.it
Galeone
Antonella
A
Venneri
Maria Teresa
MT
Coviello
Maria
M
Scrascia
Giuseppe
G
Marraudino
Nicola
N
Quaranta
Michele
M
de Luca Tupputi Schinosa
Luigi
L
Brister
Stephanie J
SJ
D001777:Blood Coagulation; D001792:Blood Platelets / Q000502:physiology; D001026:Coronary Artery Bypass; D047549:Coronary Artery Bypass, Off-Pump; D005340:Fibrinogen / Q000032:analysis; D005342:Fibrinolysis; D006801:Humans; D010446:Peptide Fragments / Q000097:blood; D017395:Plasminogen Activator Inhibitor 1 / Q000097:blood; D011516:Prothrombin; D013925:Thromboplastin / Q000032:analysis; D010959:Tissue Plasminogen Activator / Q000097:blood
D010446:Peptide Fragments; D017395:Plasminogen Activator Inhibitor 1; C045879:prothrombin fragment 1.2; D011516:Prothrombin; D005340:Fibrinogen; D013925:Thromboplastin; D010959:Tissue Plasminogen Activator