Winkel E, Kao W, Fisher S G, Heroux A L, Johnson M R, Costanzo M R
Department of Medicine, Rush Presbyterian St. Luke's Medical Center, Chicago, Ill 60612, USA.
J Heart Lung Transplant. 1998 Aug;17(8):809-16.
The use of outpatient intravenous inotropic therapy in heart transplant candidates is contentious. In addition to concerns about morbidity and mortality rates, the current United Network for Organ Sharing (UNOS) heart allocation system presently grants no waiting list priority status benefit to candidates who receive intravenous inotropic therapy in the outpatient setting (UNOS status 2), whereas identical therapy given in an intensive care unit setting does increase priority status (UNOS status 1). The goal of this study was to determine whether an increase in UNOS waiting list priority status is justified in heart transplant candidates receiving outpatient intravenous inotropic therapy by comparing the waiting list mortality of UNOS status 2 candidates on such therapy with that of UNOS status 2 candidates maintained on oral heart failure agents alone.
This is a retrospective analysis of the pretransplantation outcomes of heart transplant candidates initially listed as UNOS status 2, comparing 29 candidates receiving intravenous outpatient inotropic therapy (group 1) to 109 candidates maintained on oral heart failure agents alone (group 2).
The waiting list mortality was not significantly different between the two groups (group 1=7% vs group 2=20%, p=.18); however, group 1 patients had greater morbidity rates while awaiting transplantation than group 2 patients. A greater percentage of group 1 than group 2 patients clinically deteriorated to UNOS status 1 while awaiting transplantation (45% vs 11%), resulting in more group 1 patients undergoing transplantation overall, (59% vs 33%, p=.01) and more group 1 than group 2 patients undergoing transplantation at a higher priority status, UNOS status 1 (76% vs 33%, p=.003). Group 1 patients had more pretransplantation heart failure admissions (1.2 vs 0.6 admissions/total waiting period, p=.02) and longer hospital stays (26+/-39 vs 8.8+/-16 days, p=.03), spent a greater percentage of their total waiting time hospitalized (7% vs 2%, p=.003), and were more likely than group 2 patients to receive intravenous inotropic therapy during hospitalization (70% vs 25%, p=.001).
This study suggests that heart transplant candidates who require maintenance outpatient intravenous inotropic therapy represent a subgroup of UNOS status 2 candidates with greater waiting list morbidity, but no greater waiting list mortality than candidates who can be maintained on oral heart failure agents alone. However, the current UNOS heart allocation system provides for this increased illness acuity by assigning a higher priority status when necessary. A larger, prospective study is necessary to determine whether a true difference in waiting list mortality rates exists and if an increase in priority status is justified for UNOS status 2 candidates requiring maintenance inotropic therapy.
在心脏移植候选者中使用门诊静脉注射正性肌力药物疗法存在争议。除了对发病率和死亡率的担忧外，当前的器官共享联合网络（UNOS）心脏分配系统目前并未给予在门诊接受静脉注射正性肌力药物疗法的候选者（UNOS状态2）等待名单优先地位的益处，而在重症监护病房接受相同疗法确实会提高优先地位（UNOS状态1）。本研究的目的是通过比较接受门诊静脉注射正性肌力药物疗法的UNOS状态2候选者与仅接受口服心力衰竭药物治疗的UNOS状态2候选者的等待名单死亡率，来确定增加UNOS等待名单优先地位对接受门诊静脉注射正性肌力药物疗法的心脏移植候选者是否合理。
这是一项对最初列为UNOS状态2的心脏移植候选者移植前结局的回顾性分析，将29例接受门诊静脉注射正性肌力药物疗法的候选者（第1组）与109例仅接受口服心力衰竭药物治疗的候选者（第2组）进行比较。
两组的等待名单死亡率无显著差异（第1组=7%，第2组=20%，p = 0.18）；然而，第1组患者在等待移植期间的发病率高于第2组患者。在等待移植期间，第1组临床病情恶化至UNOS状态1的患者百分比高于第2组（45%对11%），导致第1组总体接受移植的患者更多（59%对33%，p = 0.01），且第1组以更高优先地位（UNOS状态1）接受移植的患者多于第2组（76%对33%，p = 0.003）。第1组患者移植前心力衰竭住院次数更多（1.2次对0.6次/总等待期，p = 0.02），住院时间更长（26±39天对8.8±16天，p = 0.03），在总等待时间中住院的百分比更高（7%对2%，p = 0.003），并且在住院期间比第2组患者更有可能接受静脉注射正性肌力药物疗法（70%对25%，p = 0.001）。
本研究表明，需要维持门诊静脉注射正性肌力药物疗法的心脏移植候选者是UNOS状态2候选者中的一个亚组，其等待名单发病率更高，但与仅能接受口服心力衰竭药物治疗的候选者相比，等待名单死亡率并无更高。然而，当前的UNOS心脏分配系统通过在必要时给予更高的优先地位来应对这种增加的疾病严重程度。需要进行一项更大规模的前瞻性研究，以确定等待名单死亡率是否真的存在差异，以及对于需要维持正性肌力药物疗法的UNOS状态2候选者增加优先地位是否合理。
