Differences in coronary microvascular lesions in coronary heart disease and hypertension: an autopsy study of elderly patients / 中华医学杂志(英文版)

ABSTRACT

<p><b>BACKGROUND</b>In the case of hypertension, lesions in the microvessels of the target organs precede and deteriorate further after arteriosclerosis in the small arteries. Thus coronary microvascular lesion (CML) was considered the crucial factor contributing to damage to the target organs. The purpose of this study is to observe the characteristics and differences of CML in autopsies of elderly patients with essential hypertension (EHT), coronary heart disease (CHD), or EHT with CHD, given the same degree of left ventricular wall thickness (LVWT).</p><p><b>METHODS</b>A retrospective study was performed on 246 cases of patients over 60 years old with EHT, CHD, or EHT with CHD, and on 26 cases without cardiovascular disease as controls, out of a total of 3195 consecutive autopsied cases. The arterioles (with diameter 10 - 60 microm) and the capillaries in the cardiac muscle layer were examined by haematoxylin and eosin staining, elastic van Gieson staining, and CD31 immunohistochemistry. To quantify CML severity, measurements were taken of arteriole density (AD), the ratio of wall-to-lumen area of arteriole (RWL), and capillary density (CD), using light microscopy and computer image analysis. Based on LVWT, the cases were divided into four degrees, from I to IV. The EHT, CHD, and EHT with CHD groups all rated LVWT I-IV, and the control group rated LVWT I. SAS software was used for statistical analysis.</p><p><b>RESULTS</b>With the aggravation of LVWT, both AD and RWL increased while CD decreased significantly in the EHT group (P < 0.05 - 0.0001); there were similar but more severe changes in the EHT with CHD group (P < 0.001 - 0.0001); and AD increased (P < 0.001) while RWL and CD did not change significantly in the CHD group.</p><p><b>CONCLUSION</b>Comparing EHT with CHD patients, there are similar patterns of change to AD, but different patterns of change to RWL and CD. CML is much more severe in EHT patients with CHD. We conclude that CML is one of the main causes of decreased coronary flow reserve and myocardial damage in both EHT patients and EHT patients with CHD.</p>