Volod Oksana, Lam Lee D, Lin Gloria, Kam Clarice, Kolyouthapong Kristica, Mac Jessica, Mirocha James, Ambrose Peter J, Czer Lawrence S C, Arabia Francisco A
From the *Department of Pathology, Cedars Sinai Medical Center, Los Angeles, California; ‡Cedars-Sinai Comprehensive Transplant Center, Cedars Sinai Medical Center, Los Angeles, California; §School of Pharmacy, University of California, San Francisco, California; and ¶Cedars - Sinai Research Institute (CSHI), Cedars Sinai Medical Center, Los Angeles, California.
ASAIO J. 2017 Jan/Feb;63(1):24-31. doi: 10.1097/MAT.0000000000000445.
Thromboembolic (TE) events and hemorrhagic complications continue to remain as frequent adverse events and causes of death after mechanical circulatory support device (MCSD) implantation. To counterbalance this postimplant multifactorial hypercoagulable state, antithrombotic therapy given postimplant must be individually tailored to keep patient adequately anticoagulated yet normocoagulable. Prior studies describing different anticoagulation protocols do not define normocoagulability for patients on MCSDs. We evaluated the role of thromboelastography platelet mapping (TEG PM) in defining "normocoagulability" for MCS patients on anticoagulant (warfarin) and antiplatelet agents. Ninety-eight MCSD patients who underwent TEG PM assay at our institution from 2012 to 2014 were included for retrospective analysis. Eleven (11.2%) subjects developed at least one TE event during the study period. Of the 13 TE events, 8 occurred in patients with total artificial heart (TAH). TEG parameters closest to the event or when patient was clinically adequately anticoagulated and corresponding international normalized ratio (INR) were measured. Thromboelastography coagulation index (CI) appears to be the single most statistically significant parameter that can be used to designate a patient as normocoagulable. Based on our results, patients with HeartMate II (HM II) and Heart Ware (HW) devices should be maintained at a CI value of less than or equal to 1.5 whereas patients with TAH devices should be maintained at a CI less than or equal to 1.2. The CI should be correlated with the degree of Vitamin K-dependent coagulation factor inhibition that is achieved using device-specific goal INR ranges. A recent modification, TEG PM assesses the effects of antiplatelet drug. Maximal amplitude arachidonic acid (MA-AA) < 50 and maximal amplitude adenosine diphosphate (MA-ADP) < 50 are desired for normocoagulable state.
血栓栓塞（TE）事件和出血并发症仍然是机械循环支持装置（MCSD）植入后常见的不良事件和死亡原因。为了平衡植入后这种多因素导致的高凝状态，植入后给予的抗栓治疗必须个体化定制，以使患者保持充分抗凝但凝血功能正常。先前描述不同抗凝方案的研究并未明确MCSD患者的正常凝血功能。我们评估了血栓弹力图血小板功能分析（TEG PM）在确定接受抗凝（华法林）和抗血小板药物治疗的MCS患者“正常凝血功能”中的作用。对2012年至2014年在我们机构接受TEG PM检测的98例MCSD患者进行回顾性分析。11例（11.2%）受试者在研究期间发生了至少1次TE事件。在这13次TE事件中，8次发生在植入全人工心脏（TAH）的患者中。测量了最接近事件发生时或患者临床抗凝充分时的TEG参数以及相应的国际标准化比值（INR）。血栓弹力图凝血指数（CI）似乎是最具统计学意义的单一参数，可用于判定患者凝血功能正常。根据我们的结果，使用HeartMate II（HM II）和Heart Ware（HW）装置的患者应将CI值维持在小于或等于1.5，而使用TAH装置的患者应将CI维持在小于或等于1.2。CI应与使用特定装置目标INR范围所实现的维生素K依赖凝血因子抑制程度相关。最近的一项改进是，TEG PM可评估抗血小板药物的效果。正常凝血状态下，花生四烯酸最大振幅（MA-AA）<50且二磷酸腺苷最大振幅（MA-ADP）<50。
