Division of Nephrology and Hypertension, Department of Medicine, Mayo Clinic, 200 First Street SW, Rochester, MN 55905, USA.
Am J Hypertens. 2011 Apr;24(4):458-65. doi: 10.1038/ajh.2010.259. Epub 2011 Jan 13.
Hypertension (HTN) may lead to left ventricular hypertrophy and vascular dysfunction, which are independent factors for adverse cardiovascular outcomes. We hypothesized that decreased blood pressure by percutaneous transluminal renal angioplasty (PTRA) would improve the function and architecture of coronary microvessels, in association with decreased inflammation and fibrosis.
Three groups of pigs were studied: normal, HTN, and HTN+PTRA. After 6 weeks of renovascular HTN, induced by placing a local-irritant coil in the renal artery, pigs underwent PTRA or sham. Four weeks later multidetector-computed tomography (CT) was used to assess systolic, diastolic, and microvascular function, and responses to adenosine. Microvascular architecture, oxygen sensors, inflammation, and fibrosis were then explored in cardiac tissue.
PTRA successfully decreased blood pressure and left ventricular hypertrophy. Basal fractional vascular volume (FVV) was similar among the groups, but its response to adenosine was significantly attenuated in HTN, whereas microvascular permeability (MP) and response to adenosine were greater than normal. Both were restored by PTRA. These were accompanied by increased myocardial expression of hypoxia-inducible factor (HIF)-1α, inflammation, and microvascular remodeling, including increased density of epicardial microvessels (20-200 µm), as well as cardiac diastolic dysfunction, all of which improved by reversal of HTN. However, PTRA only partially decreased myocardial fibrosis.
Reversal of early renovascular HTN improved coronary microvascular function and architecture and reversed myocardial hypertrophy and diastolic dysfunction, in association with decreased levels of myocardial ischemia and inflammation markers, underscoring the benefits of blood pressure normalization for preservation of cardiovascular function and structure.
高血压（HTN）可导致左心室肥厚和血管功能障碍，这是不良心血管结局的独立因素。我们假设经皮腔内肾血管成形术（PTRA）降低血压会改善冠状动脉微血管的功能和结构，同时降低炎症和纤维化。
研究了三组猪：正常组、HTN 组和 HTN+PTRA 组。通过在肾动脉中放置局部刺激线圈，诱导肾血管性 HTN 6 周后，对猪进行 PTRA 或假手术。4 周后，使用多排 CT 评估收缩期、舒张期和微血管功能，以及对腺苷的反应。然后在心脏组织中探索微血管结构、氧传感器、炎症和纤维化。
PTRA 成功降低了血压和左心室肥厚。各组的基础血管容积分数（FVV）相似，但 HTN 组对腺苷的反应明显减弱，而微血管通透性（MP）和对腺苷的反应大于正常组。PTRA 可恢复这些反应。这些反应伴随着心肌缺氧诱导因子（HIF）-1α、炎症和微血管重塑表达的增加，包括心外膜微血管密度（20-200 µm）的增加，以及心脏舒张功能障碍的改善，所有这些都通过逆转 HTN 得到改善。然而，PTRA 仅部分降低了心肌纤维化。
早期肾血管性 HTN 的逆转改善了冠状动脉微血管功能和结构，逆转了心肌肥厚和舒张功能障碍，同时降低了心肌缺血和炎症标志物的水平，强调了血压正常化对心血管功能和结构保护的益处。
