Cryoballoon Ablation Versus Medical Therapy in Patients With Heart Failure and Atrial Fibrillation

Rationale: Atrial fibrillation (AF) and heart failure (HF) can cause each other and sustain each other. Combined, the two diseases negatively influence each other's prognosis and lead to higher mortality. Studies in HF patients in which the AF burden is reduced by AF ablation show promising results toward improved prognosis, but so far only one randomized trial is conducted that focused on major clinical endpoints. As the selected patients in this trial were not representative for the entire population and its ablation method varied from patient to patient, it is the aim of the present study to confirm that early invasive therapy consisting of a strict pulmonary vein isolation (PVI) protocol using cryoballoon therapy has positive effects on hard clinical endpoints in a wider variety of patients in the HF population. Furthermore, there are no studies which compare cost-effectiveness of an early invasive strategy in this patient category. The investigators expect that avoided hospitalizations and healthcare resource utilizations lead to lower costs in the AF ablation group, despite initial higher costs of the procedure. Objective: To compare outcome and cost-effectiveness of early AF ablation by PVI using cryoballoon therapy with standard (medical) therapy in patients with heart failure with reduced ejection fraction. Study design: Multicenter, randomized, open label clinical trial. Study population: Symptomatic adult patients with heart failure with reduced ejection fraction (\<40%) and paroxysmal or persistent AF. Intervention: AF ablation (PVI) using cryoballoon therapy. Outcome measures: The primary endpoint is a combined endpoint of all-cause mortality, unplanned cardiovascular hospitalization, and stroke (time-to-event analysis). Secondary endpoints of the trial are: * A combined endpoint of mortality, number of unplanned cardiovascular hospitalizations, and stroke (recurrent-event analysis); * A hierarchical endpoint of mortality, unplanned cardio