心脏手术患者围术期肝素诱导的血小板减少症

Heparin-induced thrombocytopenia in patients undergoing cardiac surgery

目的:了解心脏手术患者围术期肝素诱导的血小板减少症(heparin-induced thrombocytopenia,HIT)发生率及其抗体阳性率,探索HIT发病及其抗体产生的影响因素。方法:检测连续的315例心脏手术病例手术前后血小板计数、HIT抗体、血小板因子4(platelet factor 4,PF4)。按4Ts评分诊断HIT。按性别、年龄、病种等分别统计发生率及其抗体阳性率并分析影响因素。结果:HIT发生率3.5%(11/315),HIT抗体阳性率36.5%(115/315)。其中冠心病患者HIT发生率(17.1%)高于心脏瓣膜病患者(1.9%,P<0.05)和先天性心脏病患者(0.8%,P<0.05)。先天性心脏病患者HIT抗体阳性率(51.7%)高于心脏瓣膜病患者(30.5%,P<0.05),心脏瓣膜病患者HIT抗体阳性率高于冠心病患者(14.6%,P<0.05)。HIT患者术后严重并发症发生率(36.4%)高于非HIT患者(10.5%,P<0.05)。Logistic回归示HIT发病的影响因素为年龄,HIT抗体产生的影响因素有年龄和体外循环。结论:心脏手术患者围术期HIT发生率较低,但易产生严重并发症,致残致死率高,应警惕HIT发病的危险因素。

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 HITantibody. Conclusion: 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.