Gut microbiome in heart failure and aortic stenosis.

The gut microbiome is linked to the development of individual diseases. Patients with congestive heart failure (HF) develop intestinal wall edema due to venous congestion, which impairs absorption function and allows bacterial overgrowth. Consequently, the pathogenous bacterial strains produce many harmful substances, including trimethylamine N-oxide (TMAO) and endotoxin (LPS - lipopolysaccharide), which lead to deterioration of HF. These discoveries led to hypothesis about the heart-bowel axis. High levels of TMAO present in patients with HF predispose to higher long-term mortality, even after correlation with traditional risk factors and cardiorenal indices. Most LPS is generated by the intestinal microbiome, and the osteogenic response in aortic stenosis to LPS stimulation of valve interstitial cells (VIC) is closely linked to inflammation and immunity. Thus, the concentration of intestinal microbiome research may provide new insights into the investigation of new therapeutic targets for HF and aortic stenosis.

Aortic stenosis and right ventricular dysfunction.

Cardiac damage in severe aortic stenosis (AS) is not limited to the aortic valve and left ventricle, but is a systemic disease characterized by a significant alteration in cardiac structure and function. Therefore, a new classification of AS based on the degree of myocardial damage was proposed. A significant number of patients with AS have right ventricular dysfunction likely due to ventricular interdependence. Relationship between right ventricular dysfunction and increased mortality in both symptomatic and asymptomatic patients with severe AS was demonstrated. These patients could benefit more from intervention. Therefore, a standardized echocardiographic examination of a patients with severe aortic stenosis should provide a detailed analysis of right ventricular function.

Left atrial appendage strain rate is associated with documented thromboembolism in nonvalvular atrial fibrillation.

BACKGROUND: The left atrial appendage (LAA) strain and strain rate have not yet been studied in the prediction of cardiac thromboembolism. Therefore, this study aimed to evaluate the significance of LAA strain and strain rate as assessed by speckle-tracking imaging in relation to documented thromboembolic events. METHODS: A group of 80 patients with a mean age of 65 years who were referred for electrical cardioversion of nonvalvular atrial fibrillation was retrospectively analyzed. Each patient underwent 2D transesophageal echocardiography (TEE). Velocity vector imaging (VVI)-derived LAA strain and strain rate in parallel with other conventional TEE predictors were analyzed in terms of their association with previous embolic stroke and peripheral embolization. RESULTS: By comparing the two groups of patients with (22/80) and without embolic events (58/80), patients with embolic events were older, had higher CHA2DS2-VASc scores, higher incidence of coronary artery disease and LAA thrombi, and worse LAA strain and strain rate. Moreover, patients without embolization more often used anticoagulants than patients with embolic events. After adjusting for the abovementioned embolic risk factors, only the CHA2DS2-VASc (congestive heart failure, hypertension, age ≥75 years [double weight], diabetes mellitus, stroke [double weight], vascular disease, age from 65 to 74 years, sex category) score and the LAA strain rate remained as significant predictors of embolic events. CONCLUSION: The results of the study show that the VVI-derived LAA strain rate is a significant predictor of documented ischemic stroke and systemic thromboembolism in patients with nonvalvular atrial fibrillation. Its predictive power is similar to the predictive power of the CHA2DS2-VASc score.