Department of Pathology and Molecular Medicine, McMaster University, Hamilton, Ontario, Canada.
Department of Medicine, McMaster University, Hamilton, Ontario, Canada.
J Thromb Haemost. 2022 Nov;20(11):2601-2616. doi: 10.1111/jth.15826. Epub 2022 Aug 11.
Heparin-induced thrombocytopenia (HIT) is an important adverse drug reaction that can occur postcardiac surgery. Preoperative exposure to unfractionated heparin (UFH) is common, raising the issue of how frequently cardiac surgery-associated HIT occurs after immunizing preoperative exposure to heparin.
To determine the frequency and clinical picture of HIT occurring within 4 days of cardiac surgery (early presentation) versus later presentations (typical, delayed).
We identified patients with laboratory-confirmed HIT following cardiac surgery over 30 years in a single cardiac surgery center. Three different clinical presentations of HIT were identified: typical (HIT-related platelet count fall beginning between postoperative days [PODs] 5-10), delayed (patients with falls after POD10 or who presented following hospital discharge), and early (established before POD5, including during cardiac surgery [acute intraoperative HIT]).
Of 129 patients identified with HIT complicating cardiac surgery, 100 had typical and 16 had delayed presentation of HIT; only 13 patients (10.1%) presented with early HIT, all of whom had received exposure to UFH during the 10 days before cardiac surgery. No patient was identified in whom remote preoperative UFH exposure was implicated in explaining early HIT. Notably, five patients appeared to have had acute intraoperative HIT, without immediate adverse consequences.
Approximately 90% of patients with HIT after cardiac surgery appear to develop this complication due to immunization triggered by cardiac surgery; however, in approximately 10% of patients, early presentation during the first four PODs (or intraoperatively) can be explained by recent immunizing exposure to heparin.
肝素诱导的血小板减少症（HIT）是一种重要的药物不良反应，可发生在心脏手术后。术前接触未分级肝素（UFH）很常见，这引发了一个问题，即在免疫接种术前肝素暴露后，心脏手术相关的 HIT 有多频繁发生。
确定心脏手术后 4 天内（早期表现）与较晚表现（典型、延迟）发生的 HIT 的频率和临床表现。
我们在一个单一的心脏手术中心确定了 30 多年来心脏手术后实验室确诊的 HIT 患者。确定了 HIT 的三种不同临床表现：典型（血小板计数下降开始于术后第 5-10 天[POD]）、延迟（POD10 后下降或出院后出现的患者）和早期（POD5 前确诊，包括心脏手术期间[急性术中 HIT]）。
在 129 例心脏手术后并发 HIT 的患者中，100 例有典型表现，16 例有延迟表现；仅 13 例（10.1%）出现早期 HIT，他们都在心脏手术前 10 天内接受了 UFH 暴露。没有患者被认为是由于术前 UFH 暴露导致早期 HIT。值得注意的是，有 5 例患者似乎发生了急性术中 HIT，但没有立即出现不良后果。
约 90%的心脏手术后发生 HIT 的患者似乎是由于心脏手术触发的免疫而发生这种并发症；然而，在约 10%的患者中，前 4 个 POD 期间（或手术期间）的早期表现可以用近期接触肝素的免疫来解释。
