Division of Cardiac Sciences, Libin Cardiovascular Institute, Foothills Medical Center, University of Calgary, Calgary, Alberta; Canada.
Division of Cardiology, Montreal Heart Institute, Université de Montréal, Montréal, Québec, Canada.
J Heart Lung Transplant. 2017 May;36(5):491-498. doi: 10.1016/j.healun.2017.01.003. Epub 2017 Jan 6.
Transplantation of sensitized recipients has been associated with increased risk of post-transplant complications. In 2010, the Canadian Cardiac Transplant Network (CCTN) created a unique status listing for highly sensitized heart transplant candidates. Status 4S listing requires calculated panel-reactive antibody (cPRA) level >80% as the sole listing criteria and enables geographic expansion of the donor pool by providing national access. In this study, we describe patient characteristics and outcomes of those transplanted as Status 4S in Canada.
Patients' characteristics and clinical outcomes were retrospectively collected from all 11 adult heart transplant centers in Canada.
Ninety-six patients were listed Status 4S from January 2010 to September 2015. Fifty-two were transplanted as Status 4S. Of these 52 transplants, mean cPRA level was 93.4%, mean age was 47 years, 46% were male, 44% had dilated cardiomyopathy and 17% were re-transplanted for cardiac allograft vasculopathy (CAV). Blood group O comprised 42% and 53% had a left ventricular assist device as a bridge to transplant. Desensitization therapy occurred in 9 patients (17%). Over a mean follow-up period of 28 months (1 week to 5.3 years), 9 patients died (17%). Kaplan-Meier 1-year year survival is 86%. Two patients were treated for antibody-mediated rejection (AMR) in the first year post-transplant and 33% of patients had at least 1 ISHLT Grade ≥2R cellular rejection in the first year. Twenty-nine percent of patients developed de novo door-specific antibodies and demonstrated no correlation with AMR. Freedom from CAV at 1 year is 88.5% and at 5 years is 81.0%. Fifty-two percent of donor hearts originated from outside the recipients' geographic and organ donation organization.
A national strategy of prioritizing highly sensitized heart transplant recipients has demonstrated effective expansion of the donor pool, acceptable short-term survival, freedom from CAV and low rates of clinically relevant AMR. However, we observed significantly higher rates of cellular rejection and de novo donor-specific antibody development in this population. It is currently unknown whether this will translate into poorer long-term outcome.
移植致敏受者与移植后并发症风险增加相关。2010 年，加拿大心脏移植网络（CCTN）为高度致敏的心脏移植候选者创建了独特的状态列表。4S 状态的列入标准仅为计算的群体反应性抗体（cPRA）水平>80%，通过提供全国范围内的供体来源，从而扩大供体池。本研究描述了在加拿大以 4S 状态进行移植的患者特征和结局。
从加拿大 11 个成人心脏移植中心回顾性收集所有患者的特征和临床结局数据。
2010 年 1 月至 2015 年 9 月期间，96 名患者被列入 4S 状态。其中 52 名患者以 4S 状态接受移植。在这 52 例移植中，平均 cPRA 水平为 93.4%，平均年龄为 47 岁，46%为男性，44%为扩张型心肌病，17%为因心脏同种异体移植血管病（CAV）而再次移植。血型 O 占 42%，53%有左心室辅助装置作为移植桥。9 例（17%）患者接受了脱敏治疗。平均随访 28 个月（1 周至 5.3 年）后，9 例患者（17%）死亡。Kaplan-Meier 1 年生存率为 86%。2 例患者在移植后 1 年内因抗体介导的排斥反应（AMR）接受治疗，33%的患者在第 1 年内至少发生 1 次 ISHLT 分级≥2R 的细胞排斥反应。33%的患者发生了新的门特定抗体，与 AMR 无相关性。1 年时无 CAV 发生率为 88.5%，5 年时为 81.0%。52%的供心来自受者地理和器官捐献组织以外的地区。
一项将高度致敏的心脏移植受者列为优先的国家策略已成功扩大了供体池，实现了可接受的短期生存率、无 CAV 和较低的临床相关 AMR 发生率。然而，我们在该人群中观察到更高的细胞排斥反应和新的供体特异性抗体形成率。目前尚不清楚这是否会转化为较差的长期预后。
