Analysis of mast cells and myocardial fibrosis in autopsied patients with hypertensive heart disease.

OBJECTIVE: To analyze the percentage of collagen fibers and mast cell density in the left ventricular myocardium of autopsied patients with and without hypertensive heart disease. METHODS: Thirty fragments of left ventricular myocardium were obtained from individuals autopsied at the Clinical Hospital of the Federal University of Triangulo Mineiro (UFTM) in the period from 1987 to 2017. Individuals were divided into two groups: those with hypertensive heart disease (HD) and those with no heart disease (ND). Subjects were also assessed according to age, gender and race (white and non-white). Collagen fibers were quantified by computed morphometry and mast cell density was assessed by immunohistochemical methods. RESULTS: There were significantly more collagen fibers in the left ventricle in the HD group than in the ND group (p<0.001). Mast cell density was significantly higher in the left ventricle of individuals with HD immunolabeled with anti-chymase and anti-tryptase antibodies (p=0.02) and also of those immunolabeled only with anti-tryptase antibodies (p=0.03). Analyzing the HD group, there was a significant positive correlation between the percentage of collagen fibers in the left ventricle and mast cell density immunolabeled by anti-chymase and anti-tryptase antibodies (p=0.04) and also mast cell density immunolabeled only with anti-tryptase antibodies (p=0.02). CONCLUSIONS: Mast cells are involved in the development of hypertensive heart disease, contributing to the remodeling of collagen fibers in this disease.