Microvascular Rarefaction and Myocardial Fibrosis in Hypertrophic Obstructive Cardiomyopathy: A Histopathological Comparison of Pediatric and Adult Patients

Authors

  • Mingkui Zhang, MD Heart Center, First Hospital of Tsinghua University, Beijing China
  • Zhengjie Zhang, MD Heart Center, First Hospital of Tsinghua University, Beijing China
  • Hui Xue, MD Heart Center, First Hospital of Tsinghua University, Beijing China
  • Lixin Fan, MD Heart Center, First Hospital of Tsinghua University, Beijing China
  • Yan Weng, MD The Department of Pathology, First Hospital of Tsinghua University, Beijing China

DOI:

https://doi.org/10.1532/hsf.4277

Keywords:

Hypertrophic cardiomyopathy, Microvascular density, Myocardial fibrosis, Children, Adults

Abstract

Background: Hypertrophic obstructive cardiomyopathy (HOCM) is a genetic cardiomyopathy characterized by microvascular ischemia and myocardial fibrosis. Microvessels play an important role in myocardial fibrosis in HOCM. However, the changes of myocardial microvessels and myocardial fibrosis in pediatric and adult patients with HOCM remain unclear. This study was to investigate the changes in myocardial microvessel density (MVD) and myocardial fibrosis in pediatric and adult patients with HOCM.

Methods: We analyzed the changes in MVD and myocardial fibrosis in myectomy left ventricular (LV) septal wall specimens in 12 adult patients and five pediatric patients with HOCM. Control myocardium from the LV septal wall was collected at autopsy of 5 adults and 4 pediatric individuals, who died of non-cardiac causes.

Results: There was no significant difference in MVD between pediatric HOCM patients and control subjects (706.4±187.5 vs. 940.2±491.1, P > 0.05), but the myocardial fibrosis area ratio was significantly increased in HOCM than in control subjects (10.6±3.5 vs. 4.9±1.2, P < 0.01). MVD was significantly reduced, and myocardial fibrosis area ratio was significantly higher in adult HOCM patients than in control subjects (i.e. 523.3± 209.4 vs. 845.7±260.7, P < 0.05; 12.8±5.1 vs. 4.4±1.3, P < 0.05). There was no significant difference in MVD and myocardial fibrosis between pediatric and adult HOCM patients (706.4±187.5 vs. 523.3±209.4, P > 0.05; 10.6±3.5 vs. 12.8±5.1, P > 0.05). 

Conclusions: Pediatric and adult patients with HOCM have high myocardial fibrosis. The present findings suggest that myocardial microvascular density lesions contribute to myocardial fibrosis during childhood.

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Published

2022-01-17

How to Cite

Zhang, M.-K., Zhang, Z., Xue, H., Fan, L., & Wen, Y. (2022). Microvascular Rarefaction and Myocardial Fibrosis in Hypertrophic Obstructive Cardiomyopathy: A Histopathological Comparison of Pediatric and Adult Patients. The Heart Surgery Forum, 25(1), E042-E047. https://doi.org/10.1532/hsf.4277

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