Department of Medicine, University of Chicago, Chicago, Illinois.
Advocate Heart Institute, Advocate Christ Medical Center, Oak Lawn, Illinois.
JAMA. 2024 Feb 13;331(6):500-509. doi: 10.1001/jama.2023.27029.
The US heart allocation system prioritizes medically urgent candidates with a high risk of dying without transplant. The current therapy-based 6-status system is susceptible to manipulation and has limited rank ordering ability.
To develop and validate a candidate risk score that incorporates current clinical, laboratory, and hemodynamic data.
DESIGN, SETTING, AND PARTICIPANTS: A registry-based observational study of adult heart transplant candidates (aged ≥18 years) from the US heart allocation system listed between January 1, 2019, and December 31, 2022, split by center into training (70%) and test (30%) datasets. Adult candidates were listed between January 1, 2019, and December 31, 2022.
A US candidate risk score (US-CRS) model was developed by adding a predefined set of predictors to the current French Candidate Risk Score (French-CRS) model. Sensitivity analyses were performed, which included intra-aortic balloon pumps (IABP) and percutaneous ventricular assist devices (VAD) in the definition of short-term mechanical circulatory support (MCS) for the US-CRS. Performance of the US-CRS model, French-CRS model, and 6-status model in the test dataset was evaluated by time-dependent area under the receiver operating characteristic curve (AUC) for death without transplant within 6 weeks and overall survival concordance (c-index) with integrated AUC.
A total of 16 905 adult heart transplant candidates were listed (mean [SD] age, 53 [13] years; 73% male; 58% White); 796 patients (4.7%) died without a transplant. The final US-CRS contained time-varying short-term MCS (ventricular assist-extracorporeal membrane oxygenation or temporary surgical VAD), the log of bilirubin, estimated glomerular filtration rate, the log of B-type natriuretic peptide, albumin, sodium, and durable left ventricular assist device. In the test dataset, the AUC for death within 6 weeks of listing for the US-CRS model was 0.79 (95% CI, 0.75-0.83), for the French-CRS model was 0.72 (95% CI, 0.67-0.76), and 6-status model was 0.68 (95% CI, 0.62-0.73). Overall c-index for the US-CRS model was 0.76 (95% CI, 0.73-0.80), for the French-CRS model was 0.69 (95% CI, 0.65-0.73), and 6-status model was 0.67 (95% CI, 0.63-0.71). Classifying IABP and percutaneous VAD as short-term MCS reduced the effect size by 54%.
In this registry-based study of US heart transplant candidates, a continuous multivariable allocation score outperformed the 6-status system in rank ordering heart transplant candidates by medical urgency and may be useful for the medical urgency component of heart allocation.
美国心脏分配系统优先考虑有高风险在没有移植的情况下死亡的急需医疗救治的候选人。目前基于治疗的 6 状态系统容易受到操纵，并且排名能力有限。
开发和验证一种候选风险评分，该评分纳入了当前的临床、实验室和血液动力学数据。
设计、地点和参与者：这是一项基于注册的观察性研究，研究对象为美国心脏分配系统中的成年心脏移植候选人（年龄≥18 岁），这些候选人于 2019 年 1 月 1 日至 2022 年 12 月 31 日期间在列，按中心分为训练（70%）和测试（30%）数据集。成人候选人于 2019 年 1 月 1 日至 2022 年 12 月 31 日期间在列。
通过向当前的法国候选风险评分（French-CRS）模型中添加一组预定义的预测因子，开发了美国候选风险评分（US-CRS）模型。进行了敏感性分析，其中包括在 US-CRS 中定义短期机械循环支持（MCS）时使用主动脉内球囊泵（IABP）和经皮心室辅助装置（VAD）。在测试数据集上，通过 6 周内无移植死亡的时间依赖性接收器操作特征曲线（AUC）和整体生存一致性（c-index）与综合 AUC 评估 US-CRS 模型、French-CRS 模型和 6 状态模型的性能。
共有 16905 名成年心脏移植候选人在列（平均[标准差]年龄，53[13]岁；73%为男性；58%为白人）；796 名患者（4.7%）在没有移植的情况下死亡。最终的 US-CRS 包含时间变化的短期 MCS（心室辅助-体外膜氧合或临时外科 VAD）、胆红素对数、估计肾小球滤过率、B 型利钠肽对数、白蛋白、钠和耐用性左心室辅助装置。在测试数据集上，US-CRS 模型在 6 周内死亡的 AUC 为 0.79（95%CI，0.75-0.83），French-CRS 模型为 0.72（95%CI，0.67-0.76），6 状态模型为 0.68（95%CI，0.62-0.73）。US-CRS 模型的整体 c-index 为 0.76（95%CI，0.73-0.80），French-CRS 模型为 0.69（95%CI，0.65-0.73），6 状态模型为 0.67（95%CI，0.63-0.71）。将 IABP 和经皮 VAD 归类为短期 MCS 将效果大小降低了 54%。
在这项基于美国心脏移植候选人的注册研究中，连续多变量分配评分在按医疗紧迫性对心脏移植候选人进行排名方面优于 6 状态系统，并且可能对心脏分配的医疗紧迫性部分有用。
