Background

In PHT, cardiac catheterization with endomyocardial biopsy (EMB) is standard practice for diagnosing AR and CAV but is costly and invasive.

Objectives

To evaluate the ability of cardiac magnetic resonance (CMR) to non-invasively identify differences in pediatric heart transplant (PHT) patients with acute rejection (AR) and cardiac allograft vasculopathy (CAV).

Methods

Patients were enrolled at three children’s hospitals. Data were collected from surveillance EMB or EMB for-cause AR. Patients were excluded if they had concurrent diagnoses of AR and CAV, CMR was obtained >7 days from AR diagnosis, they had EMB negative AR, or could not undergo contrasted, unsedated CMR. Kruskal-Wallis test was used to compare groups: 1. No AR or CAV (Healthy) 2. AR 3. CAV. Wilcoxon rank sum test was used for pairwise group comparisons.

Results

Fifty-nine patients met inclusion criteria (median age 17 years [IQR 15-19]) 10 (17%) with AR, and 11 (19%) with CAV. AR subjects had worse left ventricular ejection fraction (LVEF) compared to Healthy patients (p=0.001). Global circumferential strain (GCS) was worse in AR (p=0.054) and CAV (p=0.019), compared to Healthy patients. ECV, native T1, and T2 z-scores were elevated in patients with AR.

Conclusions

CMR was able to identify differences between CAV and AR patients. CAV subjects had normal global function but abnormal GCS which may suggest early subclinical dysfunction. AR patients have abnormal function and tissue characteristics consistent with edema (elevated ECV, native T1 and T2 z-scores). Characterization of CMR patterns is critical for the development of non-invasive biomarkers for PHT and may decrease dependence on EMB.

中文翻译：

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小儿心脏移植中急性排斥反应和心脏同种异体移植血管病变的心脏磁共振评估

背景

在 PHT 中，心导管插入术和心内膜心肌活检 (EMB) 是诊断 AR 和 CAV 的标准做法，但成本昂贵且具有侵入性。

目标

评估心脏磁共振 (CMR) 无创识别儿童心脏移植 (PHT) 患者急性排斥反应 (AR) 和心脏同种异体移植血管病变 (CAV) 差异的能力。

方法

患者在三家儿童医院入组。数据是从监测 EMB 或 EMB 有因 AR 收集的。如果患者同时诊断出 AR 和 CAV、自 AR 诊断后 >7 天获得 CMR、EMB 阴性 AR 或无法接受对比、未镇静的 CMR，则患者被排除。Kruskal-Wallis 检验用于比较各组： 1. 无 AR 或 CAV（健康） 2. AR 3. CAV。Wilcoxon 秩和检验用于成对组比较。

结果

59 名患者符合纳入标准（中位年龄 17 岁 [IQR 15-19]），其中 10 名 (17%) 患有 AR，11 名 (19%) 患有 CAV。与健康患者相比，AR 受试者的左心室射血分数 (LVEF) 较差 (p=0.001)。与健康患者相比，AR (p=0.054) 和 CAV (p=0.019) 的整体圆周应变 (GCS) 更差。AR 患者的 ECV、原始 T1 和 T2 z 评分升高。

结论

CMR 能够识别 CAV 和 AR 患者之间的差异。CAV 受试者的整体功能正常，但 GCS 异常，这可能表明早期亚临床功能障碍。AR 患者具有与水肿一致的功能和组织特征异常（ECV、原始 T1 和 T2 z 评分升高）。CMR 模式的表征对于 PHT 非侵入性生物标志物的开发至关重要，并且可能减少对 EMB 的依赖。