Randomized Trial Comparing Flecainide Plus Metoprolol to Metoprolol Alone for Reducing Ventricular Arrhythmias in Mitral Valve Prolapse

What this Trial Is About

Researchers are evaluating the effect and safety of adding flecainide to standard beta-blocker therapy to reduce ventricular arrhythmias in patients with arrhythmic mitral valve prolapse, a condition where the mitral valve bulges into the left atrium and can cause dangerous heart rhythms. This phase 3 randomized controlled crossover trial addresses the lack of proven treatments for patients who often experience sudden cardiac death or severe symptoms despite current therapies. The study is sponsored by Oslo University Hospital and aims to determine if combining flecainide with metoprolol is better than metoprolol alone for suppressing these arrhythmias. Participants will receive two treatment regimens in a crossover design one with flecainide added to metoprolol, and one with metoprolol alone. Flecainide is dosed starting at 50 mg twice daily, increasing to a target of 100 mg twice daily, not exceeding 300 mg daily. Metoprolol doses are adjusted based on prior use and patient needs, up to 200 mg daily, given once or twice daily depending on the formulation and preference. The first flecainide dose is given in-hospital with heart monitoring to ensure safety. Dosages are titrated during a run-in period to maximum tolerated levels. Participants will be monitored over 12 months with implantable loop recorders to track ventricular arrhythmias, alongside assessments of premature ventricular complexes, severe ventricular tachycardias, quality of life, and safety. The study uses blinded endpoint adjudication to ensure objective evaluation of arrhythmia burden. This careful monitoring includes regular ECGs and clinical assessments to evaluate how well the treatments suppress arrhythmias and affect patients well-being over time.

Effect and Safety of Flecainide and Metoprolol Versus Metoprolol Alone to Suppress Ventricular Arrhythmias in Arrhythmic Mitral Valve Prolapse