Hiemstra Jessica A, Liu Songtao, Ahlman Mark A, Schuleri Karl H, Lardo Albert C, Baines Christopher P, Dellsperger Kevin C, Bluemke David A, Emter Craig A
Department of Biomedical Science, University of Missouri- Columbia, Columbia, Missouri.
Radiology and Imaging Sciences, National Institutes of Health Clinical Center, Bethesda, Maryland ; Molecular Biomedical Imaging Laboratory, National Institute of Biomedical Imaging and Bioengineering, Bethesda, Maryland.
Physiol Rep. 2013 Dec 5;1(7):e00174. doi: 10.1002/phy2.174. eCollection 2013 Dec 1.
We recently reported that mitochondrial dysfunction, characterized by increased mitochondrial permeability transition (MPT), was present in a translational swine model of heart failure with preserved ejection fraction (HFpEF). Cyclophilin D is a key component of the MPT pore, therefore, the purpose of this study was to test the efficacy of a novel cyclosporine (CsA) dosing scheme as a therapeutic alternative for HFpEF. Computed tomography (CT), two-dimensional speckle tracking two-dimensional speckle tracking (2DST), and invasive hemodynamics were used to evaluate cardiac function. CT imaging showed 14 weeks of CsA treatment caused eccentric myocardial remodeling (contrasting concentric remodeling in untreated HF animals) and elevated systemic pressures. 2DST detected left ventricular (LV) mechanics associated with systolic and diastolic dysfunction prior to the onset of significantly increased LV end diastolic pressure including: (1) decreased systolic apical rotation rate, longitudinal displacement, and longitudinal/radial/circumferential strain; (2) decreased early diastolic untwisting and longitudinal strain rate; and (3) increased late diastolic radial/circumferential mitral strain rate. LV mechanics associated with systolic and diastolic impairment was enhanced to a greater extent than seen in untreated HF animals following CsA treatment. In conclusion, CsA treatment accelerated the development of heart failure, including dilatory LV remodeling and impaired systolic and diastolic mechanics. Although our findings do not support CsA as a viable therapy for HFpEF, 2DST was effective in differentiating between progressive gradations of developing HF and detecting diastolic impairment prior to the development of overt diastolic dysfunction.
我们最近报道,在射血分数保留的心力衰竭(HFpEF)的转化猪模型中存在以线粒体通透性转换(MPT)增加为特征的线粒体功能障碍。亲环蛋白D是MPT孔的关键组成部分,因此,本研究的目的是测试一种新型环孢素(CsA)给药方案作为HFpEF治疗替代方案的疗效。使用计算机断层扫描(CT)、二维斑点追踪(2DST)和有创血流动力学来评估心脏功能。CT成像显示,14周的CsA治疗导致偏心性心肌重塑(与未治疗的HF动物的向心性重塑形成对比)和全身压力升高。在左心室舒张末期压力显著升高之前,2DST检测到与收缩和舒张功能障碍相关的左心室(LV)力学变化,包括:(1)收缩期心尖旋转速率、纵向位移以及纵向/径向/圆周应变降低;(2)舒张早期解旋和纵向应变率降低;(3)舒张晚期二尖瓣径向/圆周应变率增加。与未治疗的HF动物相比,CsA治疗后与收缩和舒张功能损害相关的LV力学得到了更大程度的改善。总之,CsA治疗加速了心力衰竭的发展,包括扩张性LV重塑以及收缩和舒张力学受损。虽然我们的研究结果不支持将CsA作为HFpEF的可行治疗方法,但2DST在区分HF进展的不同程度以及在明显舒张功能障碍出现之前检测舒张功能损害方面是有效的。