Abstract：
OBJECTIVE: Heparin-induced thrombocytopenia (HIT) is an uncommon complication of heparin therapy with significant risk for severe morbidity and mortality. We investigated the role and outcome of direct oral anticoagulants (DOACs) for the management of HIT.
METHODS: After IRB approval, a retrospective review was performed identifying all patients with positive HIT serotonin-release assays between 2020 and 2022 at two hospitals. Demographic and clinical variables were collected: initial anticoagulant, dosing and indication, interval before onset of HIT, thrombotic complications, platelet nadir and recovery, direct thrombin inhibitor (DTI) and DOAC usage, and clinical outcomes.
RESULTS: 15 patients were included in the study. 8 underwent a vascular procedure, 3 had cardiac surgery, 1 patient had both and was included in both groups, and 5 patients had either non-cardiac, non-vascular surgery or no surgery. 14 patients received unfractionated heparin (93% with therapeutic dosing) and 1 received prophylactic enoxaparin prior to diagnosis of HIT. The average time to diagnosis of HIT was 10.77 days after initial anticoagulation. In-hospital mortality was 27%, related to Covid-19 infection (3/4) and intracranial hemorrhage (1/4). 40% developed thrombosis (67% venous, 33% arterial) after the diagnosis of HIT. 8/11 survivors were discharged on a DOAC. With DOAC therapy, platelet counts rebounded to an average of 265K (+/- 104.6K) within an average of 2.3 days and 364K (+/- 273.9K) within 30 days after initiation of a DOAC. No recurrent thrombosis occurred after DOAC administration and only one patient had persistent thrombocytopenia within 30 days.
CONCLUSIONS: Mortality and thrombosis (arterial and venous) are common complications in patients diagnosed with HIT. In patients who survive to discharge, DOACs are the most common discharge antithrombotic agent, with low rates of recurrent thrombosis and thrombocytopenia.
METHODS: After IRB approval, a retrospective review was performed identifying all patients with positive HIT serotonin-release assays between 2020 and 2022 at two hospitals. Demographic and clinical variables were collected: initial anticoagulant, dosing and indication, interval before onset of HIT, thrombotic complications, platelet nadir and recovery, direct thrombin inhibitor (DTI) and DOAC usage, and clinical outcomes.
RESULTS: 15 patients were included in the study. 8 underwent a vascular procedure, 3 had cardiac surgery, 1 patient had both and was included in both groups, and 5 patients had either non-cardiac, non-vascular surgery or no surgery. 14 patients received unfractionated heparin (93% with therapeutic dosing) and 1 received prophylactic enoxaparin prior to diagnosis of HIT. The average time to diagnosis of HIT was 10.77 days after initial anticoagulation. In-hospital mortality was 27%, related to Covid-19 infection (3/4) and intracranial hemorrhage (1/4). 40% developed thrombosis (67% venous, 33% arterial) after the diagnosis of HIT. 8/11 survivors were discharged on a DOAC. With DOAC therapy, platelet counts rebounded to an average of 265K (+/- 104.6K) within an average of 2.3 days and 364K (+/- 273.9K) within 30 days after initiation of a DOAC. No recurrent thrombosis occurred after DOAC administration and only one patient had persistent thrombocytopenia within 30 days.
CONCLUSIONS: Mortality and thrombosis (arterial and venous) are common complications in patients diagnosed with HIT. In patients who survive to discharge, DOACs are the most common discharge antithrombotic agent, with low rates of recurrent thrombosis and thrombocytopenia.
摘要：
目的：肝素诱导的血小板减少症（HIT）是肝素治疗的一种罕见并发症，具有严重的发病率和死亡率的显著风险。我们调查了直接口服抗凝剂（DOAC）在HIT管理中的作用和结果。
方法：IRB批准后，我们进行了一项回顾性审查,确定了在2020年至2022年期间在两家医院HIT血清素释放试验阳性的所有患者.收集人口统计学和临床变量：初始抗凝剂，给药和适应症，发作前的间隔，血栓性并发症,血小板最低点和恢复，直接凝血酶抑制剂（DTI）和DOAC的使用，和临床结果。
结果：15名患者被纳入研究。8人接受了血管手术，3人做了心脏手术,1名患者同时患有这两种疾病，并被纳入两组，5名患者患有非心脏疾病，非血管手术或不手术。14例患者在诊断HIT之前接受普通肝素（治疗剂量为93％），1例接受预防性依诺肝素。初始抗凝后，诊断HIT的平均时间为10.77天。住院死亡率为27%，与Covid-19感染（3/4）和颅内出血（1/4）有关。40%发生血栓形成（67%静脉，33%动脉)诊断后HIT。8/11幸存者使用DOAC出院。使用DOAC治疗，血小板计数在DOAC开始后平均2.3天内反弹至平均265K(+/-104.6K),在30天内反弹至364K(+/-273.9K).DOAC给药后未发生复发性血栓形成，只有一名患者在30天内出现持续性血小板减少症。
结论：死亡率和血栓形成（动脉和静脉）是诊断为HIT的患者的常见并发症。在存活出院的患者中，DOAC是最常见的释放抗血栓药物，血栓形成和血小板减少的复发率低。
方法：IRB批准后，我们进行了一项回顾性审查,确定了在2020年至2022年期间在两家医院HIT血清素释放试验阳性的所有患者.收集人口统计学和临床变量：初始抗凝剂，给药和适应症，发作前的间隔，血栓性并发症,血小板最低点和恢复，直接凝血酶抑制剂（DTI）和DOAC的使用，和临床结果。
结果：15名患者被纳入研究。8人接受了血管手术，3人做了心脏手术,1名患者同时患有这两种疾病，并被纳入两组，5名患者患有非心脏疾病，非血管手术或不手术。14例患者在诊断HIT之前接受普通肝素（治疗剂量为93％），1例接受预防性依诺肝素。初始抗凝后，诊断HIT的平均时间为10.77天。住院死亡率为27%，与Covid-19感染（3/4）和颅内出血（1/4）有关。40%发生血栓形成（67%静脉，33%动脉)诊断后HIT。8/11幸存者使用DOAC出院。使用DOAC治疗，血小板计数在DOAC开始后平均2.3天内反弹至平均265K(+/-104.6K),在30天内反弹至364K(+/-273.9K).DOAC给药后未发生复发性血栓形成，只有一名患者在30天内出现持续性血小板减少症。
结论：死亡率和血栓形成（动脉和静脉）是诊断为HIT的患者的常见并发症。在存活出院的患者中，DOAC是最常见的释放抗血栓药物，血栓形成和血小板减少的复发率低。
