Division of Cardiovascular Medicine, Stanford University School of Medicine, Stanford, California.
Department of Cardiothoracic Surgery, Stanford University School of Medicine, Stanford, California.
J Heart Lung Transplant. 2018 Sep;37(9):1060-1066. doi: 10.1016/j.healun.2018.04.008. Epub 2018 Apr 26.
Proposed changes to the United Network for Organ Sharing heart transplant allocation protocol will prioritize patients receiving temporary mechanical circulatory support (tMCS), including extracorporeal membrane oxygenation (ECMO), percutaneous ventricular assist devices (PVADs), and intra-aortic balloon pumps (IABPs). We sought to evaluate contemporary trends in the incidence and outcomes of patients who required tMCS during the hospitalization before heart transplantation.
Using the National Inpatient Sample from 1998 to 2014, we identified 6,892 patients who received an orthotopic heart transplant and classified them by pre-transplant ECMO, PVAD, or IABP placement or no pre-transplant tMCS. We compared baseline characteristics and in-hospital outcomes between patients who underwent pre-transplant ECMO, PVAD, or IABP and patients who did not receive tMCS before heart transplantation.
Of patients who underwent heart transplantation, 456 (6.6%) received tMCS before transplant. During the study period, the use of tMCS more than doubled, from 17 cases per year from 1998 to 2002 to 40 cases per year from 2012 to 2014 (p < 0.001 for trend). Of patients with tMCS, 341 (74.8%) were supported by IABP, 130 (28.5%) were supported by ECMO, and 21 (4.6%) were supported by PVAD. Before 2007, patients who required tMCS had higher in-hospital mortality than patients who did not require tMCS before transplant (14.3% vs 7.5%, p = 0.05). In the subsequent era (2007 to 2014), mortality was not significantly different (4.7% vs 5.1%, p = 0.9). Hospital mortality improved over time for all patients but most significantly in patients who required tMCS (9.6% absolute risk reduction). However, patients who received tMCS had increased lengths of stays and rates of acute renal, hepatic, and respiratory failure, sepsis, bleeding complications, and surgical reoperations.
The use of tMCS before cardiac transplantation is increasing, with no difference in in-patient post-transplant mortality in the recent era between patients who did and did not receive tMCS but with increased complication rates among those who received tMCS. These data support the use of tMCS before cardiac transplantation in appropriately selected patients. Clinicians should balance the above outcomes when making decisions to implant tMCS, given the impending changes to the United Network for Organ Sharing heart allocation protocol.
美国器官共享网络（United Network for Organ Sharing）心脏移植分配方案的修改建议将优先考虑接受临时机械循环支持（tMCS）的患者，包括体外膜肺氧合（ECMO）、经皮心室辅助装置（PVAD）和主动脉内球囊泵（IABP）。我们试图评估在心脏移植前住院期间需要 tMCS 的患者的发生率和结局的当代趋势。
我们使用 1998 年至 2014 年期间的全国住院患者样本，确定了 6892 名接受原位心脏移植的患者，并根据移植前 ECMO、PVAD 或 IABP 放置或无移植前 tMCS 对他们进行分类。我们比较了接受移植前 ECMO、PVAD 或 IABP 与未接受心脏移植前 tMCS 的患者之间的基线特征和住院结局。
在接受心脏移植的患者中，有 456 例（6.6%）在移植前接受了 tMCS。在此期间，tMCS 的使用增加了一倍以上，从 1998 年至 2002 年每年 17 例增加到 2012 年至 2014 年每年 40 例（趋势 p <0.001）。在接受 tMCS 的患者中，341 例（74.8%）接受 IABP 支持，130 例（28.5%）接受 ECMO 支持，21 例（4.6%）接受 PVAD 支持。在 2007 年之前，需要 tMCS 的患者的院内死亡率高于未接受移植前 tMCS 的患者（14.3%对 7.5%，p=0.05）。在随后的时代（2007 年至 2014 年），死亡率没有显著差异（4.7%对 5.1%，p=0.9）。所有患者的住院死亡率随时间改善，但在需要 tMCS 的患者中改善最为显著（绝对风险降低 9.6%）。然而，接受 tMCS 的患者住院时间延长，急性肾、肝和呼吸衰竭、败血症、出血并发症和再次手术的发生率增加。
心脏移植前 tMCS 的使用正在增加，在最近的时代，接受和不接受 tMCS 的患者在住院后移植死亡率方面没有差异，但接受 tMCS 的患者的并发症发生率更高。这些数据支持在适当选择的患者中使用心脏移植前 tMCS。鉴于美国器官共享网络心脏分配方案即将发生变化，临床医生在决定植入 tMCS 时应权衡上述结果。
