Activation of coagulation and fibrinolysis during coronary surgery: on-pump versus off-pump techniques.
BACKGROUND
The authors studied the changes in selected hemostatic variables in patients undergoing coronary surgery with on-pump coronary artery bypass grafting (CABG) or off-pump coronary artery bypass surgery (OPCAB) techniques.


METHODS
Platelet counts and plasma concentrations of antithrombin, fibrinogen, D dimer, alpha(2) antiplasmin, and plasminogen were measured preoperatively, 5 min after administration of heparin, 10 min after arrival in the intensive care unit, and 24 h after surgery in patients scheduled to undergo OPCAB (n = 15) or CABG (n = 15). To correct for dilution, hemostatic variables and platelet counts were adjusted for the changes in immunoglobulin G plasma concentrations and hematocrit, respectively.


RESULTS
Adjusting for dilution, antithrombin and fibrinogen concentrations decreased to a similar extent in patients undergoing OPCAB or CABG (pooled means and 95% confidence limits of the mean: 95.5% of baseline, 93-98%, P = 0.002, and 91.7% of baseline, 88-95%, P = 0.0001), respectively, whereas alpha(2)-antiplasmin concentrations were unchanged. Only CABG was associated with a reduction in platelet counts (76% of baseline, 66-85%, P = 0.0001), plasminogen concentrations (96% of baseline, 91-99%, P = 0.011), and increased D-dimer formation (476%, 309-741%, P = 0.004). Twenty-four hours after surgery, platelet counts were still lower in patients undergoing CABG (P = 0.049), but all the investigated variables adjusted for dilution were similar in the two groups.


CONCLUSIONS
Coronary surgery causes a net consumption of antithrombin and fibrinogen. A transient decrease in platelet counts, with plasminogen activation and increased D-dimer formation, however, is only observed with CABG. Twenty-four hours after surgery, the hemostatic profiles of patients in both groups are similar.
Casati
V
V
Department of Anesthesiology, University of Milan, Italy. valter.casati@tin.it
Gerli
C
C
Franco
A
A
Della Valle
P
P
Benussi
S
S
Alfieri
O
O
Torri
G
G
D'Angelo
A
A
D001777:Blood Coagulation; D001026:Coronary Artery Bypass / Q000379:methods*; D005260:Female; D005338:Fibrin Fibrinogen Degradation Products / Q000378:metabolism; D005342:Fibrinolysis; D006400:Hematocrit; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood; D008297:Male; D008875:Middle Aged; D010958:Plasminogen / Q000378:metabolism; D010976:Platelet Count; D011184:Postoperative Period; D011446:Prospective Studies
D005338:Fibrin Fibrinogen Degradation Products; D007074:Immunoglobulin G; C036309:fibrin fragment D; D010958:Plasminogen