Surgical bleeding after pre-operative unfractionated heparin and low molecular weight heparin for coronary bypass surgery.
OBJECTIVE
Since the impairment of platelet function may cause excess peri-operative bleeding, pre-operative discontinuation of aspirin and heparin bridging are common for cardiac surgery. We evaluated the impact of pre-operative administration of enoxaparin and unfractionated heparin (UFH) on coagulation parameters and peri-operative bleeding in patients undergoing elective coronary artery bypass grafting (CABG) surgery after discontinuation of aspirin.


METHODS
Forty-three patients with three-vessel coronary artery disease undergoing elective CABG surgery discontinued aspirin and were randomized to receive either UFH 180 UI/Kg x 2/day s.c. or enoxaparin 100 UI/Kg x 2/day s.c. until 12 h before surgery (median pre-operative treatment 8 days, range 6-12 days). Surgery was performed as usual with UFH. Neither UFH nor any low molecular weight heparin was given in the immediate post-operative period. The effects of UFH and enoxaparin were monitored by the activated partial thromboplastin time (aPTT) and the Enox-test (sensitive to factor Xa inhibition) using a Rapidpoint Coagulation Analyzer. aPTT and factor Xa activity were also measured by standard methods. Peri-operative bleeding and the nadirs of hemoglobin concentration, hematocrit and platelet count were monitored post-operatively.


RESULTS
Patients in the two groups were similar for number of bypasses, on-pump time, total surgery time, and time from the last heparin administration. Coagulation parameters increased significantly and similarly at 30 min and 6 h with both treatments, but returned within the normal range at 12 h. Hemoglobin, hematocrit and platelet counts significantly decreased to the same extent after CABG and re-normalized at the same time. Transfusional requirements of blood and plasma units were similar in the two groups.


CONCLUSIONS
From the kinetics of coagulation parameters and the evaluation of bleeding, enoxaparin is a safe alternative to UFH as a bridging therapy to CABG after discontinuation of aspirin.
Renda
Giulia
G
Institute of Cardiology, G. d'Annunzio University, Chieti, Italy.
Di Pillo
Raffaele
R
D'Alleva
Alberto
A
Sciartilli
Adolfo
A
Zimarino
Marco
M
De Candia
Erica
E
Landolfi
Raffaele
R
Di Giammarco
Gabriele
G
Calafiore
Antonio
A
De Caterina
Raffaele
R
D000328:Adult; D000368:Aged; D000925:Anticoagulants / Q000008:administration & dosage / Q000009:adverse effects* / Q000627:therapeutic use; D001780:Blood Coagulation Tests; D016063:Blood Loss, Surgical / Q000517:prevention & control / Q000706:statistics & numerical data*; D001026:Coronary Artery Bypass; D003327:Coronary Disease / Q000601:surgery; D017558:Elective Surgical Procedures; D017984:Enoxaparin / Q000008:administration & dosage / Q000009:adverse effects* / Q000627:therapeutic use; D015951:Factor Xa / Q000032:analysis; D005260:Female; D006454:Hemoglobins / Q000032:analysis; D006493:Heparin / Q000008:administration & dosage / Q000009:adverse effects* / Q000627:therapeutic use; D006801:Humans; D008297:Male; D008875:Middle Aged; D010314:Partial Thromboplastin Time; D010976:Platelet Count; D011183:Postoperative Complications / Q000517:prevention & control; D019106:Postoperative Hemorrhage / Q000139:chemically induced; D011229:Preanesthetic Medication / Q000009:adverse effects*; D011300:Preoperative Care / Q000009:adverse effects*; D018401:Sample Size; D013927:Thrombosis / Q000517:prevention & control
D000925:Anticoagulants; D017984:Enoxaparin; D006454:Hemoglobins; D006493:Heparin; D015951:Factor Xa