Acute intraoperative heparin-induced thrombocytopenia (HIT) and thrombosis during coronary artery bypass grafting: Two case reports providing evidence for the role of preoperative LMWH in triggering sensitization.
BACKGROUND
Systemic anticoagulation is necessary during cardiac surgery. To date, the only well established anticoagulation protocol involves the use of heparin. However, heparin can cause heparin-induced thrombocytopenia (HIT) a potentially life threatening immune-mediated thromboembolic syndrome. Until now, devastating consequences of HIT syndrome in patients undergoing heart surgery have been described, but only postoperatively. Here we report the development of HIT syndrome during cardiac revascularization by intra-operative heparin administration in two patients previously exposed to LMWH.


METHODS
We report on two patients who developed rapid and profound intravascular coagulation with severe thrombocytopenia (platelet count decreased from ≥250×109/L to 50×109/L) due to HIT development caused by heparin administration during coronary artery bypass graft surgery. In addition we report that fondaparinux, given intra-operatively in association with antithrombin, may be a suitable alternative anticoagulant for successfully preventing the devastating consequences of intra-operative HIT development.


CONCLUSIONS
To our knowledge, this is the first report describing the development of acute intra-operative HIT, secondary to high-dose UFH administered for coronary revascularization, in which the unexpected presence of platelet-activating anti-PF4/heparin antibodies at surgery was explained by preoperative administration of a one-week course of LMWH but without any preoperative evidence for HIT.
2nd Department of Heart Surgery, Onassis Cardiac Surgery Center, Athens, Greece.
M
M
Khoury
St. Luke Heart Institute, Thessaloniki, Greece.
A
A
Pitsis
St. Luke Heart Institute, Thessaloniki, Greece.
H
H
Poumpouridou-Kioura
Haematology and Blood transfusion Department, Onassis Cardiac Surgery Center, Athens, Greece.
G
G
Soufla
Department of Oncology, School of Medicine, University of Sheffield, UK.
C
C
Kanthou
Haematology and Blood transfusion Department, Onassis Cardiac Surgery Center, Athens, Greece.
N
N
Matoula
Haematology and Blood transfusion Department, Onassis Cardiac Surgery Center, Athens, Greece.
A
A
Angelidis
Haematology and Blood transfusion Department, Onassis Cardiac Surgery Center, Athens, Greece. Electronic address: melisari@ocsc.gr.
E
E
Melissari
D000368:Aged; D001026:Coronary Artery Bypass / Q000379:methods*; D006495:Heparin, Low-Molecular-Weight / Q000009:adverse effects*; D006801:Humans; D008297:Male; D008875:Middle Aged; D013921:Thrombocytopenia / Q000139:chemically induced*; D013927:Thrombosis / Q000188:drug therapy*
D006495:Heparin, Low-Molecular-Weight
CPB; Fondaparinux; HIT; Thrombocytopenia; Thromboembolism