Sherazi Saadia, Kouides Peter, Francis Charles, Lowenstein Charles Julian, Refaai Majed, Conley Grace, Johnson Brent Alan, Muchnik Eugene, Lien Susan, Massey Howard Todd, Alexis Jeffrey Dean
1 Cardiology Division, School of Medicine & Dentistry, University of Rochester, Rochester, NY, USA.
2 Hematology/Oncology Division, School of Medicine & Dentistry, University of Rochester, Rochester, NY, USA.
Int J Artif Organs. 2018 May;41(5):269-276. doi: 10.1177/0391398818762353. Epub 2018 Mar 22.
Bleeding is a major cause of morbidity in patients with continuous flow left ventricular assist devices (LVADs). We sought to identify clinical predictors of bleeding within the first year of LVAD implantation.
A prospective study was performed on 30 patients with HeartMate II implantation at the University of Rochester Medical Center, Rochester, New York, United States. Blood was collected within 1 week before implantation, and at 1, 3, and 30 ± 10 days after implantation. Blood samples were analyzed for prothrombin time (PT), international normalized ratio (INR), von Willebrand factor (vWF) activity, vWF antigen, vWF multimers, collagen binding assay, factor VIII, and epinephrine closure time. The first bleeding event within 1 year of implantation was recorded.
There were 17 (57%) patients with a bleeding event. The cumulative incidence of bleeding was 50% at 304 days. Age at the time of LVAD implantation was associated with higher risk of bleeding (hazard ratio (HR) = 1.05, 95% confidence interval (CI) = 1.01-1.10, p = 0.013). Higher baseline INR was also associated with increased risk of bleeding after adjusting for age at the time of implant (HR = 6.58, 95% CI = 1.21-35.70, p = 0.028). The bleeders and non-bleeders had similar hemostatic markers at all four time points. Prior to LVAD, mean epinephrine closure time was similar between bleeders and non-bleeders. However, post LVAD measurement of epinephrine, closure time was frequently limited by platelet clumping.
Older age and baseline INR are associated with higher risk of bleeding in LVAD patients. Platelet clumping may suggest underlying platelet dysfunction and associated high risk of bleeding.
出血是持续血流左心室辅助装置（LVAD）患者发病的主要原因。我们试图确定LVAD植入后第一年出血的临床预测因素。
在美国纽约罗切斯特的罗切斯特大学医学中心，对30例植入HeartMate II的患者进行了一项前瞻性研究。在植入前1周内以及植入后1、3和30±10天采集血液。分析血样的凝血酶原时间（PT）、国际标准化比值（INR）、血管性血友病因子（vWF）活性、vWF抗原、vWF多聚体、胶原结合试验、因子VIII和肾上腺素封闭时间。记录植入后1年内的首次出血事件。
有17例（57%）患者发生出血事件。304天时出血的累积发生率为50%。LVAD植入时的年龄与出血风险较高相关（风险比（HR）=1.05，95%置信区间（CI）=1.01 - 1.10，p = 0.013）。调整植入时的年龄后，较高的基线INR也与出血风险增加相关（HR = 6.58，95%CI = 1.21 - 35.70，p = 0.028）。在所有四个时间点，出血者和未出血者具有相似的止血标志物。在LVAD植入前，出血者和未出血者的平均肾上腺素封闭时间相似。然而，LVAD植入后肾上腺素测量时，封闭时间经常受血小板聚集限制。
年龄较大和基线INR与LVAD患者出血风险较高相关。血小板聚集可能提示潜在的血小板功能障碍及相关的高出血风险。
