BACKGROUND

Right heart failure (RHF) in pulmonary hypertension (PH) patients is manifested by increased right atrial (RA) pressure. We hypothesized liver relaxation times measured at cardiovascular magnetic resonance (CMR) can be used to noninvasively assess increased right-sided filling pressure.

METHODS

Forty-five consecutive patients, that is, 37 PH patients and 8 chronic thromboembolic pulmonary disease patients without PH underwent right heart catheterization and CMR. CMR findings were compared to 40 control subjects. Native T1, T2, and extracellular volume (ECV) liver values were measured on the cardiac maps.

RESULTS

Patients with increased RA pressure (i.e.,≥8 mm Hg)(n = 19, RA+ group) showed higher NT-proBNP and CRP values, lower LVEF, MAPSE values, larger atrial size, and higher native T1 and T2 values of the myocardium than patients with normal RA pressure (RA- group, n = 26). Liver T1, T2 and ECV was significantly higher in RA+ than RA- patients and controls, that is, T1: 684 ± 129 ms vs 563 ± 72 ms and 540 ± 34 ms; T2: 60 ± 10 ms vs 49 ± 6 ms and 46 ± 4 ms; ECV: 36 ± 8% vs 29 ± 4% and 30 ± 3%. A positive correlation was found between liver T1, T2 and ECV and RA pressure, that is, r² of 0.61, 0.82, and 0.58, respectively (p < 0.001). ROC analysis to depict increased RA pressure showed an AUC of 0.847, 0.904, 0.816, and 0.645 for liver T1, T2, NT-proNBP and gamma-glutamyl transpeptidase, respectively. Excellent intra- and inter-observer agreement was found for assessment of T1/T2/ECV liver values.

CONCLUSIONS

Assessment of liver relaxation times as part of a comprehensive CMR exam in PH patients may provide valuable information with regard to the presence of passive liver congestion.

中文翻译：

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肝脏磁共振弛豫测量法——一种评估肺动脉高压右心衰竭的新成像生物标志物

背景

肺动脉高压 (PH) 患者的右心衰竭(RHF) 表现为右心房 (RA) 压力升高。我们假设心血管磁共振 (CMR) 测量的肝脏舒张时间可用于无创评估增加的右侧充盈压。

方法

连续 45 例患者，即 37 例 PH 患者和 8 例没有 PH 的慢性血栓栓塞性肺病患者接受了右心导管插入术和 CMR。将 CMR 结果与 40 名对照受试者进行比较。在心脏图上测量原生 T1、T2 和细胞外体积 (ECV) 肝脏值。

结果

RA 压力升高（即≥8 mm Hg）的患者（n  = 19，RA+ 组）显示更高的 NT-proBNP 和 CRP 值，更低的 LVEF、MAPSE 值、更大的心房大小以及更高的心肌原生 T1 和 T2 值比正常 RA 压力的患者（RA-组，n  = 26）。RA+ 患者和对照组的肝脏 T1、T2 和 ECV 显着高于 RA- 患者和对照组，即 T1：684 ± 129 ms vs 563 ± 72 ms 和 540 ± 34 ms；T2：60 ± 10 ms vs 49 ± 6 ms 和 46 ± 4 ms；ECV：36 ± 8% 对比 29 ± 4% 和 30 ± 3%。肝脏 T1、T2 和 ECV 与 RA 压力呈正相关，即 r ²分别为 0.61、0.82 和 0.58（p< 0.001)。描述 RA 压力增加的 ROC 分析显示，肝脏 T1、T2、NT-proNBP 和 γ-谷氨酰转肽酶的 AUC 分别为 0.847、0.904、0.816 和 0.645。在评估 T1/T2/ECV 肝脏值时发现了出色的观察者内部和观察者间一致性。

结论

作为 PH 患者综合 CMR 检查的一部分，评估肝脏松弛时间可以提供有关被动肝充血存在的有价值信息。