Centre for Cardiovascular Science, University of Edinburgh, Edinburgh, UK.
Department of Cardiovascular Sciences, University of Edinburgh, Edinburgh, UK.
Open Heart. 2019 Oct 3;6(2):e001115. doi: 10.1136/openhrt-2019-001115. eCollection 2019.
Ultra-small superparamagnetic particles of iron oxide (USPIO)-enhanced MRI can detect cellular inflammation within tissues and may help non-invasively identify cardiac transplant rejection. Here, we aimed to determine the normal reference values for USPIO-enhanced MRI in patients with a prior cardiac transplant and examine whether USPIO-enhanced MRI could detect myocardial inflammation in patients with transplant rejection.
Ten volunteers and 11 patients with cardiac transplant underwent T2, T2* and late gadolinium enhancement 1.5T MRI, with further T2* imaging at 24 hours after USPIO (ferumoxytol, 4 mg/kg) infusion, at baseline and 3 months.
Ten patients with clinically stable cardiac transplantation were retained for analysis. Myocardial T2 values were higher in patients with cardiac transplant versus healthy volunteers (53.8±5.2 vs 48.6±1.9 ms, respectively; p=0.003). There were no differences in the magnitude of USPIO-induced change in R2* in patients with transplantation (change in R2*, 26.6±7.3 vs 22.0±10.4 s in healthy volunteers; p=0.28). After 3 months, patients with transplantation (n=5) had unaltered T2 values (52.7±2.8 vs 52.12±3.4 ms; p=0.80) and changes in R2* following USPIO (29.42±8.14 vs 25.8±7.8 s; p=0.43).
Stable patients with cardiac transplantation have increased myocardial T2 values, consistent with resting myocardial oedema or fibrosis. In contrast, USPIO-enhanced MRI is normal and stable over time suggesting the absence of chronic macrophage-driven cellular inflammation. It remains to be determined whether USPIO-enhanced MRI may be able to identify acute cardiac transplant rejection.
NCT02319278349 (https://clinicaltrials.gov/ct2/show/NCT02319278) Registered 03.12.2014 EUDraCT 2013-002336-24.
超小超顺磁性氧化铁颗粒（USPIO）增强 MRI 可检测组织内的细胞炎症，并且可能有助于无创性识别心脏移植排斥。在此，我们旨在确定先前接受过心脏移植的患者的 USPIO 增强 MRI 的正常参考值，并检查 USPIO 增强 MRI 是否可以检测到移植排斥患者的心肌炎症。
10 名志愿者和 11 名心脏移植患者接受了 1.5T 的 T2、T2和晚期钆增强 MRI 检查，并在基线和 3 个月后进行了进一步的 USPIO（ferumoxytol，4mg/kg）输注后 24 小时的 T2成像。
保留了 10 名临床稳定的心脏移植患者进行分析。与健康志愿者相比，心脏移植患者的心肌 T2 值更高（分别为 53.8±5.2 和 48.6±1.9ms；p=0.003）。移植患者 USPIO 诱导的 R2变化幅度无差异（变化幅度，26.6±7.3 和健康志愿者的 22.0±10.4s；p=0.28）。3 个月后，移植患者（n=5）的 T2 值保持不变（52.7±2.8 和 52.12±3.4ms；p=0.80），USPIO 后 R2的变化（29.42±8.14 和 25.8±7.8s；p=0.43）。
心脏移植稳定患者的心肌 T2 值升高，与静息性心肌水肿或纤维化一致。相比之下，USPIO 增强 MRI 是正常且稳定的，这表明没有慢性巨噬细胞驱动的细胞炎症。尚待确定 USPIO 增强 MRI 是否能够识别急性心脏移植排斥。
NCT02319278349（https://clinicaltrials.gov/ct2/show/NCT02319278）于 2014 年 12 月 3 日注册 EUDraCT 2013-002336-24。
