Wesley Medical Research Limited, Auchenflower, Queensland, Australia
St Andrew's War Memorial Hospital, Spring Hill, Queensland, Australia.
Open Heart. 2021 Apr;8(1). doi: 10.1136/openhrt-2020-001565.
Point of care viscoelastic measures with thromboelastography (TEG; Haemonetics Corporation, Switzerland) and thromboelastometry (ROTEM, Tem Innovations GmbH, Germany) now supersede laboratory assays in the perioperative assessment and management of coagulation. To the best of our knowledge, this sophisticated coagulation assessment has not been performed to characterise thrombotic changes in the transcatheter aortic valve implantation (TAVI) setting, nor have the two latest iteration cartridge-based systems been directly compared in the elective perioperative period.
Patients undergoing TAVI were prospectively recruited. Samples (n=44) were obtained at four timepoints (postinduction of anaesthesia, postheparin (100 IU/kg), postprotamine (1 mg/100 IU heparin) and 6 hours postoperatively). Each sample was concurrently assessed with standard laboratory tests (prothrombin time/international normalised ratio, activated partial thromboplastin time, thrombin clotting time, platelet count and direct fibrinogen, ROTEMSigma and TEG6s).
Clot strength showed a statistically significant increase postheparin/TAVI deployment. When considering the subgroup of samples taken following the administration heparin, the heparinase channel of the TEG6s did not yield clotting strength results in 55% of samples and clotting time exceeded the upper limit of normal in 70% of samples. It was retrospectively recognised that the arachidonic acid channel of the TEG6s Platelet Mapping Cartridge had been decommissioned prohibiting assessment of aspirin effect.
This study demonstrated a small intraprocedural prothrombotic change of uncertain clinical importance during the transcatheter aortic valve procedure. Further comparison with percutaneous coronary intervention and aortic valve replacement cohorts are needed to assess the merits of current antithrombotic guidelines, which are extrapolated from the PCI setting. The heparin effect was more consistently quantified by ROTEM.
即时检测血栓弹力图（TEG；Haemonetics 公司，瑞士）和血栓弹力描记法（ROTEM，Tem Innovations GmbH，德国）等床边检测方法现已取代实验室检测，用于围术期凝血评估和管理。据我们所知，这种复杂的凝血评估尚未用于描述经导管主动脉瓣植入术（TAVI）过程中的血栓变化，也没有直接比较过最新的两款基于试剂盒的系统在择期围术期的情况。
前瞻性招募接受 TAVI 的患者。在四个时间点（麻醉诱导后、肝素后（100IU/kg）、鱼精蛋白后（1mg/100IU 肝素）和术后 6 小时）采集样本（n=44）。每个样本均同时用标准实验室检测（凝血酶原时间/国际标准化比值、活化部分凝血活酶时间、凝血酶时间、血小板计数和直接纤维蛋白原、ROTEMSigma 和 TEG6s）进行评估。
肝素后/TAVI 放置后，凝块强度显示出统计学上的显著增加。当考虑肝素后采集的样本亚组时，TEG6s 的肝素酶通道在 55%的样本中未产生凝块强度结果，在 70%的样本中凝血时间超过正常值上限。回顾性发现，TEG6s 血小板图谱试剂盒的花生四烯酸通道已停用，禁止评估阿司匹林的作用。
本研究显示，经导管主动脉瓣术过程中存在较小的术中促血栓形成变化，但临床意义不确定。需要进一步与经皮冠状动脉介入治疗和主动脉瓣置换队列进行比较，以评估从 PCI 环境中推断而来的当前抗血栓形成指南的优势。ROTEM 更一致地量化了肝素的作用。
