Heart Failure and Preserved Ejection Fraction

The goal of this clinical trial is to learn if a digital lifestyle education program improves exercise capacity in adults who have heart failure with preserved ejection fraction (HFpEF) and overweight or obesity. HFpEF is a type of heart failure in which the heart muscle is stiff and does not relax well, even though its pumping strength looks normal. The main questions it aims to answer are: * Does the program improve how much oxygen participants can use during exercise, a measure of fitness, after 6 months? * Does the program improve participants' quality of life and help them lose weight? Researchers will compare a group that uses the digital program plus usual care to a group that receives usual care alone. This will show whether the program adds a benefit. Participants will: * Be placed by chance into one of the two groups * Use a study website with short videos on exercise, healthy eating, and managing stress (program group), with new content every week for 6 months * Have exercise tests, an ultrasound scan of the heart, blood tests, and complete a quality-of-life questionnaire at the start and after 6 months Both groups will keep taking their usual heart failure medicines.

Heart failure is a serious condition in which the heart is unable to pump blood effectively, and it remains a leading cause of hospitalization and death worldwide despite advances in treatment. Selenium is an essential micronutrient that plays an important role in cellular energy production, antioxidant defense, and overall cardiovascular function. Low selenium levels are common among patients with heart failure in Northern Europe, and observational studies have shown that selenium deficiency is associated with an increased risk of hospitalization and death. In cases of severe deficiency, such as in Keshan disease, heart dysfunction can be reversed with selenium supplementation, suggesting a potential causal relationship. However, it is not yet known whether selenium supplementation can improve clinical outcomes in patients with heart failure when added to standard medical therapy. The SIRI-HF trial is a randomized, placebo-controlled study designed to evaluate whether daily supplementation with 200 micrograms of selenium, in addition to guideline-directed medical therapy, improves outcomes in patients with heart failure. The primary endpoint is a composite of recurrent heart failure hospitalizations and cardiovascular death. Secondary endpoints include all-cause mortality, changes in symptoms and functional status, and safety outcomes. This study will include patients from Sweden and Norway and aims to determine whether correcting selenium deficiency can improve prognosis in heart failure.

Obesity, severe overweight, is a growing problem worldwide and increases the risk of heart failure, especially a type called heart failure with preserved ejection fraction (HFpEF). In HFpEF, the heart becomes stiffer. This makes it harder for the heart to fill with blood, which can lead to shortness of breath during physical activity. In the Netherlands, 15% of the population has obesity. In South Limburg, this is even higher at 19%. Among people with HFpEF, obesity is much more common: about 50% of these patients have obesity. Life expectancy in people with HFpEF is poor, and current treatment mainly focuses on reducing symptoms. Early recognition and treatment of risk factors, such as obesity, are therefore very important. This study includes about 250 people with obesity. Using a heart ultrasound and tests of blood and fat tissue, we will look for early signs of HFpEF and study the effects of weight loss. The measurements will be repeated after 1 and 2 years. The goal of this study is to better understand how obesity contributes to HFpEF and how weight loss affects the heart. This research may help improve future treatments for patients with HFpEF.