Angiology and Blood Coagulation Unit , IRCCS, Azienda Ospedaliero-Universitaria di Bologna, Bologna, Italy.
Angiology and Blood Coagulation Unit, Department of Medical and Surgical Sciences, University of Bologna, Bologna, Italy.
Intern Emerg Med. 2023 Oct;18(7):1971-1980. doi: 10.1007/s11739-023-03379-5. Epub 2023 Aug 12.
Heparin-induced thrombocytopenia (HIT) is a rare immuno-mediated adverse reaction with high thrombotic and mortality risk. To evaluate incidence and outcomes of HIT cases diagnosed at a tertiary care hospital from 2007 to 2018. A retrospective study was conducted. Patients with suspected HIT underwent 4Ts score assessment and anti-heparin PF4 IgG antibodies ELISA screening test. If the latter was positive, platelet aggregation test (PAT) was performed. If the latter was positive, any form of heparin was stopped, alternative anticoagulants were started and then overlapped with warfarin. HIT incidence was calculated by dividing HIT cases by the mean yearly number of admitted patients over 11 years. Follow-up was 90 days. Among 2125 screening tests, 96 (4.5%) were positive with confirmatory PAT in 82/90 (3.8% for missing data in 6). Median age was 75; 39 patients were surgical and 51 medical. The median 4Ts score was 5. Unfractionated heparin was employed in 34 (37%). HIT incidence was 0.16/1000/patient/years (95% CI: 0.12-0.23) in surgical and 0.15/1000/patient/years (95%: 0.12-0.20) in medical patients. HIT with thrombosis (HIT-T) was observed in 31 patients (0.05/1000/patient/years 95% CI: 0.04-0.1), with venous thromboses in 25 (80%). HIT without thrombosis was observed in 59 patients (0.1/1000 patient/years; 95% CI: 0.08-0.13, twofold vs HIT-T). All cause mortality was 25.5% (95% CI: 17.6-35.4), major bleeding 7.7% (95% CI:3.2-15.3), and thromboembolic complications 3.3% (95% CI:1.1-9.3). HIT is a rare event with high mortality, despite the use of non heparin anticoagulants.
肝素诱导的血小板减少症（HIT）是一种罕见的免疫介导的不良反应，具有较高的血栓形成和死亡率风险。评估 2007 年至 2018 年在一家三级保健医院诊断的 HIT 病例的发生率和结局。进行了一项回顾性研究。对疑似 HIT 的患者进行 4Ts 评分评估和抗肝素 PF4 IgG 抗体 ELISA 筛选试验。如果后者阳性，则进行血小板聚集试验（PAT）。如果后者阳性，则停用任何形式的肝素，改用其他抗凝药物，并与华法林重叠。通过将 HIT 病例除以 11 年内平均每年入院患者人数来计算 HIT 发生率。随访 90 天。在 2125 次筛查试验中，96 次（4.5%）经确认性 PAT 呈阳性，6 次（3.8%）因数据缺失而呈阳性。中位年龄为 75 岁；39 例为外科患者，51 例为内科患者。中位数 4Ts 评分为 5。普通肝素用于 34 例（37%）。外科患者的 HIT 发生率为 0.16/1000/患者/年（95%CI：0.12-0.23），内科患者为 0.15/1000/患者/年（95%CI：0.12-0.20）。观察到 31 例 HIT 伴血栓形成（HIT-T）（0.05/1000/患者/年，95%CI：0.04-0.1），其中静脉血栓形成 25 例（80%）。59 例患者观察到无血栓形成的 HIT（0.1/1000 患者/年；95%CI：0.08-0.13，两倍于 HIT-T）。全因死亡率为 25.5%（95%CI：17.6-35.4），大出血率为 7.7%（95%CI：3.2-15.3），血栓栓塞并发症发生率为 3.3%（95%CI：1.1-9.3）。尽管使用了非肝素抗凝剂，HIT 仍是一种罕见的事件，死亡率较高。
