Division of Cardiovascular Surgery, Tohoku University Graduate School of Medicine, Sendai, Japan.
Department of Molecular and Cellular Biology, Institute of Development, Aging, and Cancer, Tohoku University, Sendai, Japan.
Eur J Cardiothorac Surg. 2018 Nov 1;54(5):841-846. doi: 10.1093/ejcts/ezy172.
Acquired von Willebrand syndrome, characterized by the reduction in von Willebrand factor (vWF) large multimers, has recently been considered as one of the causes of gastrointestinal bleeding (GIB). It remains unclear whether its haematological severity is linked with susceptibility to bleeding because the definition of the haematological severity of acquired von Willebrand syndrome has not been precisely determined. This study sought to establish a quantitative methodology to assess the haematological severity of acquired von Willebrand syndrome and to define the threshold for occurrence of GIB in patients implanted with left ventricular assist devices (LVADs).
In total, 41 patients treated with continuous-flow LVAD implanted between 2011 and 2017 at Tohoku University Hospital were investigated. vWF large multimers were quantitatively evaluated using the 'vWF large multimer index' defined as the ratio of a large multimer proportion in total vWF derived from a patient to that from a normal control. Using this index, the amount of vWF large multimers was expressed as a percentage of its normal control value obtained with a simultaneous analysis of each time measurement.
Twelve (29%) patients developed GIB events during follow-up periods (median 591 days) after an LVAD implantation. The vWF large multimer index in patients with GIB was significantly lower than that in those without GIB (25.0 ± 10.3% vs 37.5 ± 17.8%, P = 0.008). Most importantly, all patients experiencing GIB exhibited a vWF large multimer index below 40%.
Patients with GIB exhibited a more severe loss of vWF large multimers. The vWF large multimer index may dictate the risk of GIB after an LVAD implantation.
UMIN000018135.
获得性血管性血友病（von Willebrand syndrome，vWD）的特征是血管性血友病因子（von Willebrand factor，vWF）大多聚体减少，最近被认为是胃肠道出血（gastrointestinal bleeding，GIB）的原因之一。由于尚未精确确定获得性 vWD 血液学严重程度的定义，因此其血液学严重程度与出血易感性之间的关系尚不清楚。本研究旨在建立一种定量方法来评估获得性 vWD 的血液学严重程度，并确定植入左心室辅助装置（left ventricular assist devices，LVAD）患者发生 GIB 的阈值。
共调查了 2011 年至 2017 年在东北大学医院接受连续血流 LVAD 治疗的 41 例患者。使用“vWF 大多聚体指数”定量评估 vWF 大多聚体，该指数定义为患者 vWF 大多聚体比例与正常对照 vWF 大多聚体比例的比值。使用该指数，将 vWF 大多聚体的量表示为与每次时间测量同时进行的正常对照值的百分比。
12 例（29%）患者在 LVAD 植入后随访期间（中位数 591 天）发生 GIB 事件。GIB 患者的 vWF 大多聚体指数明显低于无 GIB 患者（25.0±10.3%比 37.5±17.8%，P=0.008）。最重要的是，所有发生 GIB 的患者均表现出 vWF 大多聚体指数低于 40%。
发生 GIB 的患者 vWF 大多聚体丢失更为严重。vWF 大多聚体指数可能决定 LVAD 植入后 GIB 的风险。
UMIN000018135。
