Department of Cardiology, 5F, VU University Medical Center, De Boelelaan 1117, 1081 HV, Amsterdam, The Netherlands.
Eur J Nucl Med Mol Imaging. 2010 Apr;37(4):779-88. doi: 10.1007/s00259-009-1350-3. Epub 2010 Jan 13.
Next to hypertrophy, hypertrophic cardiomyopathy (HCM) is characterized by alterations in myocardial energetics. A small number of studies have shown that myocardial external efficiency (MEE), defined by external work (EW) in relation to myocardial oxidative metabolism (MVO(2)), is reduced. The present study was conducted to identify determinants of MEE in patients with HCM by use of dynamic positron emission tomography (PET) and cardiovascular magnetic resonance imaging (CMR).
Twenty patients with HCM (12 men, mean age: 55.2 + or - 13.9 years) and 11 healthy controls (7 men, mean age: 48.1 + or - 10 years) were studied with [(11)C]acetate PET to assess MVO(2). CMR was performed to determine left ventricular (LV) volumes and mass (LVM). Univariate and multivariate analyses were employed to determine independent predictors of myocardial efficiency.
Between study groups, MVO(2) (controls: 0.12 + or - 0.04 ml x min(-1) x g(-1), HCM: 0.13 + or - 0.05 ml x min(-1) x g(-1), p = 0.64) and EW (controls: 9,139 + or - 2,484 mmHg x ml, HCM: 9,368 + or - 2,907 mmHg x ml, p = 0.83) were comparable, whereas LVM was significantly higher (controls: 99 + or - 21 g, HCM: 200 + or - 76 g, p < 0.001) and MEE was decreased in HCM patients (controls: 35 + or - 8%, HCM: 21 + or - 10%, p < 0.001). MEE was related to stroke volume (SV), LV outflow tract gradient, NH(2)-terminal pro-brain natriuretic peptide (NT-proBNP) and serum free fatty acid levels (all p < 0.05). Multivariate analysis revealed that SV (ss = 0.74, p < 0.001) and LVM (ss = -0.43, p = 0.013) were independently related to MEE.
HCM is characterized by unaltered MVO(2), impaired EW generation per gram of myocardial tissue and subsequent deteriorated myocardial efficiency. Mechanical external efficiency could independently be predicted by SV and LVM.
除了肥大之外，肥厚型心肌病（HCM）的特征还在于心肌能量代谢的改变。少数研究表明，心肌外效率（MEE）降低，其定义为（EW）与心肌氧化代谢（MVO₂）的关系。本研究旨在通过动态正电子发射断层扫描（PET）和心血管磁共振成像（CMR）来确定 HCM 患者 MEE 的决定因素。
20 名 HCM 患者（12 名男性，平均年龄：55.2±13.9 岁）和 11 名健康对照组（7 名男性，平均年龄：48.1±10 岁）接受了 [(11)C]醋酸盐 PET 以评估 MVO₂。CMR 用于确定左心室（LV）容积和质量（LVM）。采用单变量和多变量分析确定心肌效率的独立预测因素。
在研究组之间，MVO₂（对照组：0.12±0.04ml·min⁻¹·g⁻¹，HCM：0.13±0.05ml·min⁻¹·g⁻¹，p=0.64）和 EW（对照组：9139±2484mmHg·ml，HCM：9368±2907mmHg·ml，p=0.83）相当，而 LVM 明显较高（对照组：99±21g，HCM：200±76g，p<0.001），并且 HCM 患者的 MEE 降低（对照组：35±8%，HCM：21±10%，p<0.001）。MEE 与每搏量（SV）、LV 流出道梯度、N 末端脑利钠肽前体（NT-proBNP）和血清游离脂肪酸水平相关（均 p<0.05）。多变量分析显示，SV（ss=0.74，p<0.001）和 LVM（ss=-0.43，p=0.013）与 MEE 独立相关。
HCM 的特征是 MVO₂ 不变、心肌组织每克产生的 EW 减少以及随后的心肌效率恶化。SV 和 LVM 可独立预测机械外效率。
