Department of Surgery, University of Mississippi Medical Center, Jackson, MS, USA.
Department of Data Science, University of Mississippi Medical Center, Jackson, MS, USA.
Transpl Int. 2021 Nov;34(11):2184-2191. doi: 10.1111/tri.14116. Epub 2021 Oct 7.
Heterotopic heart transplantation (HHT) is rare in the modern era. When used as a biologic left ventricular assist, HHT provides pulsatile flow, supports the left ventricle with a physiologic cardiac output, responds to humoral stimuli, and with modern immunosuppression may offer long-term untethered survival. This study was undertaken to compare survival of HHT with orthotopic heart transplantation (OHT) to assess its viability in the modern era. In the United Network for Organ Sharing database, from January 1999 to December 2020, there were 27691 bicaval OHT, 13836 biatrial OHT, 1271 total OHT, and 51 HHT with sufficient follow-up. Survival was analyzed using restricted mean survival time (RMST) through 4 years as the outcome. In the first 4 years after transplant, compared with HHT, differences in RMST were 0.1 years (99% CI: -0.4 to 0.5 years) for bicaval OHT, 0.0 years (99% CI: -0.4 to 0.5 years) for biatrial OHT, and 0.0 years (99% CI: -0.5 to 0.4 years) for total OHT. In this cohort, survival was indistinguishable between HHT and OHT recipients in the first four years. Thus, HHT might be a viable alternative to durable mechanical circulatory assist particularly with size mismatched grafts or for patients with refractory pulmonary hypertension.
异种心脏移植（Heterotopic heart transplantation，HHT）在现代较为罕见。当用作生物左心室辅助装置时，HHT 可提供脉动血流，以生理心输出量支持左心室，对体液刺激做出反应，并且在现代免疫抑制治疗下，可能实现长期无束缚的存活。本研究旨在比较 HHT 与原位心脏移植（Orthotopic heart transplantation，OHT）的存活率，以评估其在现代的可行性。在美国器官共享网络数据库中，1999 年 1 月至 2020 年 12 月，共有 27691 例双腔 OHT、13836 例双房 OHT、1271 例全心脏 OHT 和 51 例 HHT 有足够的随访。使用限制性平均生存时间（restricted mean survival time，RMST）作为 4 年的结局进行生存分析。在移植后前 4 年，与 HHT 相比，双腔 OHT、双房 OHT 和全心脏 OHT 的 RMST 差异分别为 0.1 年（99%置信区间：-0.4 年至 0.5 年）、0.0 年（99%置信区间：-0.4 年至 0.5 年）和 0.0 年（99%置信区间：-0.5 年至 0.4 年）。在该队列中，HHT 与 OHT 受者在前 4 年的生存无显著差异。因此，HHT 可能是一种可行的替代方案，特别是对于需要大小匹配的移植物或对肺动脉高压有抗性的患者，可替代持久的机械循环辅助。
