PhD defence Y.S. (Yaar) Aga

Summary:

Obesity significantly increases the risk of developing heart failure. With current diagnostic techniques, it is currently difficult to recognize signs of cardiac dysfunction and heart failure in people with obesity. The overall goal of this thesis is to study signs of early cardiac dysfunction and to investigate the role of speckle tracking echocardiography and biomarkers in the early detection of cardiac dysfunction in people with obesity. In this thesis, we have shown that measurements such as left atrium strain and left ventricular global longitudinal strain, measured by speckle tracking echocardiography, better and earlier detect signs of cardiac dysfunction in people with obesity. Abnormalities in strain parameters are already visible, while no abnormalities are found in conventional echocardiographic parameters. Furthermore, we found that in a large proportion of people with obesity, cardiac dysfunction is reversible one year after bariatric surgery. In a panel of 92 biomarkers, we found that people with obesity have elevated markers related to inflammation, fibrosis, and atherosclerosis. In 78% of the examined biomarkers, there was a significant change one year after bariatric surgery. In people where cardiac dysfunction persisted one year after bariatric surgery, biomarkers related to inflammation and insulin resistance were found to be important predictors for the persistence of cardiac dysfunction. These results are important, especially considering the increasing prevalence of obesity worldwide and the associated risk of heart failure. Early and accurate detection of signs of heart failure can ultimately lead to earlier treatment and patient management. The results in this thesis show that there are better methods for detecting heart failure in people with severe obesity, which is important for clinical practice and can be applied.