Doença valvar cardíaca em pacientes com morbidades metabólicas: uma análise histopatológica e metagenômica. Estudo de série de casos

Abstract

Heart disease has been the leading cause of death worldwide. Among these conditions, calcification of heart valves stands out, occurring due to a degenerative process influenced by infections associated with an inflammatory state. In this context, the objective of this study was to identify the microorganisms present in heart valves removed from cardiac patients through metagenomic analysis. This is an observational, cross-sectional, case-control study of samples collected from heart valves of patients undergoing valve replacement surgery. 27 valve leaflets from patients with valvular heart disease and 9 from the control group were histologically analyzed for the presence of inflammation and mineralizations. Giemsa and Grocott histochemical analyses were performed to evaluate possible bacteria and fungi present in the sample. The DNAs from the heart valve samples were extracted and frozen for PCR analysis. Furthermore, metagenomic sequencing of the 16S and 18S rRNA regions was performed, followed by bioinformatic analysis. The results demonstrated an unfavorable cardiometabolic profile, with hyperglycemia and reduced HDL cholesterol. Histologically, diffuse fibrosis, chronic inflammation, myxoid degeneration, and calcification predominated. Histochemical analysis with Groccot and Giemsa staining identified a significant frequency of structures compatible with microorganisms, especially bacteria and fungi. Metagenomic analysis identified potentially opportunistic bacteria and fungi, including Staphylococcus, Sphingomonas, Actinotignum, Cutaneotrichosporon, and Apiotrichum. It is concluded that the valvular heart diseases analyzed present a multifactorial character, involving interactions between metabolic, inflammatory, degenerative, and microbiological alterations, highlighting the relevance of metagenomics as a complementary tool in the investigation of valvular heart diseases.