AV Junction Ablation or Optimal Medical Treatment in PatiEnts With Cardiac Resynchronization Therapy and Permanent Atrial Fibrillation

This trial is comparing two strategies for people with atrial fibrillation (AFib) and heart failure who have already had a cardiac resynchronization therapy (CRT) device implanted — a device that helps both sides of the heart beat in a coordinated way. The study compares optimal medication management alone versus adding an ablation procedure (using heat to destroy the junction between the upper and lower heart chambers) to force the CRT device to fully control the heartbeat. **You may be eligible if...** - You have had a CRT device (biventricular pacemaker or conduction system pacemaker) for more than 6 months - You have permanent or recurrent persistent atrial fibrillation requiring emergency care or hospitalization - You are on optimized heart failure medications and rate control drugs - You are between 18 and 85 years old **You may NOT be eligible if...** - You do not have atrial fibrillation or heart failure requiring a CRT device - Your ventricular pacing from the CRT device is already nearly 100% - You have severe health conditions that make ablation unsafe Talk to your doctor to see if this trial is right for you.