[Heparin-induced thrombocytopenia in patients  undergoing cardiac surgery].
OBJECTIVE
To investigate the incidence for heparin-induced thrombocytopenia (HIT) in patients undergoing cardiac surgery and to evaluate the risk factors for the generation of HIT-antibody.


METHODS
A total of 315 patients undergoing cardiac surgery in the Department of Cardiothoracic Surgery, Xiangya Hospital between December, 2013 and July, 2014 were enrolled for this study. Among them, 120, 154 and 41 were for surgery of congenital heart defect, valve and coronary artery bypass graft, respectively. There were 170 male patients and 69 patients were under 18 years old. Platelet counts, HIT-antibody and concentration of platelet factor 4 (PF4) were tested before and after the surgery. Diagnosis of HIT was based on "4Ts" (Pretest Clinical Scoring System).


RESULTS
HIT was diagnosed in 11 patients (3.5%, 11/315). And thromboembolic events occurred in 2 of 11 patients with HIT. The positive ratio for HIT-antibody was 36.5% (115/315). The coronary artery disease patients had a higher incidence of HIT than that of either the valve disease or the congenital heart defect (17.1%, 7/41 versus 1.9%, 3/154 or 0.8%, 1/120; P<0.05). The congenital heart defect patients had a higher positive ratio for HIT-antibody than that of both the valve disease and the coronary artery disease. The valve disease patients had a higher positive ratio for HIT-antibody than that of the coronary artery disease (51.7%, 62/120 versus 30.5%, 47/154 versus 14.6%, 6/41; P<0.05). Major postoperative complications occurred more frequently in HIT patients (36.4%, 4/11 versus 10.5%, 32/304; P<0.05). Age was a risk factor for HIT (P=0.030, OR=1.083, 95% CI 1.008-1.163). Cardiopulmonary bypass (CPB) (P=0.037, OR=3.113, 95% CI 1.071-9.050) and age (P<0.001, OR=0.970, 95% CI 0.959-0.982) were risk factors for HIT-antibody.


CONCLUSIONS
The incidence of HIT is low during cardiac surgery, but HIT is a highly risk factor for the major postoperative complications. More attentions should be paid to these severe complications and the risk factors for HIT.
Department of Cardiothoracic Surgery, Xiangya Hospital, Central South University, Changsha 410008, China.
Fushuo
F
Zhou
Department of Cardiothoracic Surgery, Xiangya Hospital, Central South University, Changsha 410008, China.
Lingjin
L
Huang
Department of Anesthesiology, Xiangya Hospital, Central South University, Changsha 410008, China.
E
E
Wang
Department of Cardiothoracic Surgery, Xiangya Hospital, Central South University, Changsha 410008, China.
Guoqiang
G
Lin
Department of Cardiothoracic Surgery, Xiangya Hospital, Central South University, Changsha 410008, China.
Wanjun
W
Luo
D000906:Antibodies / Q000097:blood; D006348:Cardiac Surgical Procedures; D002315:Cardiopulmonary Bypass; D001026:Coronary Artery Bypass; D005260:Female; D006493:Heparin / Q000009:adverse effects*; D006801:Humans; D015994:Incidence; D008297:Male; D010976:Platelet Count; D010978:Platelet Factor 4 / Q000097:blood; D011183:Postoperative Complications; D012307:Risk Factors; D013921:Thrombocytopenia / Q000139:chemically induced*
D000906:Antibodies; D010978:Platelet Factor 4; D006493:Heparin