Imaging intestinal morphological changes in dogs with congestive heart failure: Ultrasonographic approach in the gut-heart axis

Objective: The aim of this thesis study was to evaluate cardiovascular (cTnI, Nt-proBNP, CK-MB, Myoglobin and D-dimer) and intestinal (Zonulin and DAO) biomarkers and echocardiographic and intestinal ultrasonographic changes in dogs with CHF. Materials and Methods: Dogs with CHF (n=25) and healthy dogs (n=10) that applied to Adnan Menderes University, Faculty of Veterinary Medicine, Internal Medicine Small Animals Polyclinic were included in the study. The dogs included in the study were evaluated in terms of radiographic, echocardiographic, intestinal ultrasonographic findings and biomarkers related to cardiovascular and intestinal permeability. In the analysis of the data, Mann-Whitney U, Chi-square and Spearman's rho tests were performed using SPSS program. Results: In the study, CHF group dogs were compared with each other and with healthy group dogs. Evaluation of echocardiographic data revealed higher left atrium/aorta LA/Ao (p=0.000), EDV (p=0.045), SV (p=0.019), E/A (p=0.001) and E/IVRT (p=0.001) values in the CHF group compared to the healthy group; lower IVSd (p=0.001), IVRT (p=0.000) and IVRT/(E/A) (p=0.000) values. Each of the evaluated cardiovascular and intestinal permeability biomarkers was determined to be statistically significantly higher in the CHF group compared to the healthy group. Colon wall thickness determined by intestinal ultrasonography was found to be significantly higher in CHF dogs compared to healthy groups (p=0.000), but no significant difference was observed in duodenum and jejunum wall thicknesses. In dogs with CHF, intestinal wall thickness was found to correlate significantly with various echocardiographic parameters, including weak to modrate correlations between duodenal and jejunal thickness and diastolic function indices and modrate positive correlations between colonic thickness and E wave velocity. In dogs with CHF, intestinal wall thickness correlated significantly with various echocardiographic parameters. Duodenal wall thickness correlated with E, E/A, DT, E/IVRT (weakly negative), and IVRT/(E/A) (modrately positive). Jejunal wall thickness correlated with LA/Ao, E/A, DT, E/IVRT (negative); A, IVRT/(E/A), LVIDs, EF (positive). Colonic wall thickness correlated with E (modrately positive), IVRT, and E/IVRT (weakly). No statistically significant correlations were found between duodenal and colonic wall thickness and any of the cardiovascular and intestinal permeability biomarkers. Jejunal wall thickness showed low positive correlation with cTnI, low negative correlation with myoglobin and DAO. Conclusion: The determination of colon wall thickness increase accompanied by significant and strong statistically high values of cardiovascular and intestinal permeability biomarkers in CHF group dogs compared to healthy individuals and the modrate increase in E wave velocity and weak decrease in IVRT and E/IVRT values among echocardiographic parameters with this increase; although it is associated with a low sample pool, it indicates the existence of a relationship between diastolic dysfunction and colon dysfunction. Further studies with larger sample groups regarding the findings regarding the heart-gut axis will contribute to the elucidation of the pathophysiological mechanisms of bidirectional interactions within this axis and to the determination of the potential diagnostic and prognostic value of GIS changes in HF.