Improving exercise capacity and quality of life using non-invasive heart failure treatments: evidence from clinical trials

Abstract

Endpoints of large-scale trials in chronic heart failure have mostly been defined to evaluate treatments with regard to hospitalizations and mortality. However, patients with heart failure are also affected by very severe reductions in exercise capacity and quality of life. We aimed to evaluate the effects of heart failure treatments on these endpoints using available evidence from randomized trials. Interventions with evidence for improvements in exercise capacity include physical exercise, intravenous iron supplementation in patients with iron deficiency, and - with less certainty - testosterone in highly selected patients. Erythropoiesis-stimulating agents have been reported to improve exercise capacity in anaemic patients with heart failure. Sinus rhythm may have some advantage when compared with atrial fibrillation, particularly in patients undergoing pulmonary vein isolation. Studies assessing treatments for heart failure co-morbidities such as sleep-disordered breathing, diabetes mellitus, chronic kidney disease and depression have reported improvements of exercise capacity and quality of life; however, the available data are limited and not always consistent. The available evidence for positive effects of pharmacologic interventions using angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, beta-blockers, and mineralocorticoid receptor antagonists on exercise capacity and quality of life is limited. Studies with ivabradine and with sacubitril/valsartan suggest beneficial effects at improving quality of life; however, the evidence base is limited in particular for exercise capacity. The data for heart failure with preserved ejection fraction are even less positive, only sacubitril/valsartan and spironolactone have shown some effectiveness at improving quality of life. In conclusion, the evidence for state-of-the-art heart failure treatments with regard to exercise capacity and quality of life is limited and appears not robust enough to permit recommendations for heart failure. The treatment of co-morbidities may be important for these patient-related outcomes. Additional studies on functional capacity and quality of life in heart failure are required.

Keywords: Exercise capacity; Heart failure; Quality of life.