Morphological and histopathological evaluation of autopsied patients with hypertensive cardiopathy.

Background: Physiopathological processes in hypertensive heart disease are controlled by complex interactions between cardiomyocytes, extracellular matrix, microvasculature and other cells present in the myocardium.

Objective: To analyze morphological changes in hypertensive cardiopathy and to describe and compare findings in order to help clarify determinant factors.

Methods: 42 fragments of the left ventricular myocardium and circumflex branch of the left coronary artery were obtained from individuals autopsied at the Clinical Hospital of the Federal University of Triângulo Mineiro (UFTM) in the period ranging from 1984 to 2018. Groups were split into individuals with hypertensive heart disease (HD) and individuals without heart disease (ND). Wall thickness was measured with a digital caliper and Computed Tomography. Quantification of collagen fibers was conducted by computerized morphometry and mast cell density was assessed by immunohistochemical methods.

Results: There was a significant increase of heart weight in the HD group compared to the ND group, (p = 0.0002). There was a significant increase of thickness of the middle third of the free wall in the HD group compared to the ND group, (p = 0.04). There was a significant increase of collagen fibers in the left ventricle in the HD group compared to the ND group, (p < 0.0001). Concerning mast cell density, there was a significant increase in the left ventricle of individuals with HD immuno-labeled by the set anti-chymase/anti-tryptase (p < 0.0001). There was a significant increase of mast cell density in the circumflex branch of the left coronary artery of individuals with HD immuno-labeled by the set anti-chymase/anti-tryptase (p = 0.01).

Conclusions: Mast cells are involved in the development of hypertensive heart disease, contributing to the remodeling of collagen fibers in this disease.