Yoshinaga Keiichiro, Ohira Hiroshi, Tsujino Ichizo, Oyama-Manabe Noriko, Mielniczuk Lisa, Beanlands Rob S B, Katoh Chietsugu, Kasai Katsuhiko, Manabe Osamu, Sato Takahiro, Fujii Satoshi, Ito Yoichi M, Tomiyama Yuuki, Nishimura Masaharu, Tamaki Nagara
Department of Molecular Imaging, Hokkaido University Graduate School of Medicine, Kita 15 Nishi 7, Kita-Ku, Sapporo, Hokkaido, Japan, 060-8638,
Eur J Nucl Med Mol Imaging. 2014 Jun;41(6):1240-50. doi: 10.1007/s00259-014-2736-4. Epub 2014 Mar 11.
The right ventricle (RV) has a high capacity to adapt to pressure or volume overload before failing. However, the mechanisms of RV adaptation, in particular RV energetics, in patients with pulmonary hypertension (PH) are still not well understood. We aimed to evaluate RV energetics including RV oxidative metabolism, power and efficiency to adapt to increasing pressure overload in patients with PH using (11)C-acetate PET.
In this prospective study, 27 patients with WHO functional class II/III PH (mean pulmonary arterial pressure 39.8 ± 13.5 mmHg) and 9 healthy individuals underwent (11)C-acetate PET. (11)C-acetate PET was used to simultaneously measure oxidative metabolism (k mono) for the left ventricle (LV) and RV. LV and RV efficiency were also calculated.
The RV ejection fraction in PH patients was lower than in controls (p = 0.0054). There was no statistically significant difference in LV k mono (p = 0.09). In contrast, PH patients showed higher RV k mono than did controls (0.050 ± 0.009 min(-1) vs. 0.030 ± 0.006 min(-1), p < 0.0001). PH patients exhibited significantly increased RV power (p < 0.001) and hence increased RV efficiency compared to controls (0.40 ± 0.14 vs. 0.017 ± 0.12 mmHg·mL·min/g, p = 0.001).
The RV oxidative metabolic rate was increased in patients with PH. Patients with WHO functional class II/III PH also had increased RV power and efficiency. These findings may indicate a myocardial energetics adaptation response to increasing pulmonary arterial pressure.
右心室（RV）在发生衰竭前具有较高的适应压力或容量超负荷的能力。然而，肺动脉高压（PH）患者右心室适应的机制，尤其是右心室能量代谢，仍未得到充分了解。我们旨在使用（11）C - 乙酸盐PET评估PH患者右心室能量代谢，包括右心室氧化代谢、功率和效率，以适应不断增加的压力超负荷。
在这项前瞻性研究中，27例世界卫生组织功能分级为II/III级的PH患者（平均肺动脉压39.8±13.5 mmHg）和9名健康个体接受了（11）C - 乙酸盐PET检查。（11）C - 乙酸盐PET用于同时测量左心室（LV）和右心室的氧化代谢（k单）。还计算了左心室和右心室的效率。
PH患者的右心室射血分数低于对照组（p = 0.0054）。左心室k单无统计学显著差异（p = 0.09）。相比之下，PH患者的右心室k单高于对照组（0.050±0.009 min（-1）对0.030±0.006 min（-1），p < 0.0001）。与对照组相比，PH患者的右心室功率显著增加（p < 0.001），因此右心室效率也增加（0.40±0.14对0.017±0.12 mmHg·mL·min/g，p = 0.001）。
PH患者的右心室氧化代谢率增加。世界卫生组织功能分级为II/III级的PH患者的右心室功率和效率也增加。这些发现可能表明心肌能量代谢对不断增加的肺动脉压的适应性反应。
