Inclusion Criteria:  Age ≥ 18 years. Moderate-severe or severe TR while in atrial fibrillation. Ambulatory (not wheelchair/scooter dependent). Patient willing to consider surgical management of severe TR  Exclusion Criteria:  Systolic pulmonary artery pressure>70 mmHg with a fixed pulmonary vascular resistance >7 Wood units by catheterization. Ejection fraction <40%. Obstructive hypertrophic cardiomyopathy. Constrictive pericarditis or tamponade. Active myocarditis. Complex congenital heart disease. Other valve disease requiring surgical intervention. Terminal illness (other than HF) with expected survival of less than 1 year. Enrollment or planned enrollment in another therapeutic clinical trial in next 3 months. Inability to comply with planned study procedures. Pregnancy or breastfeeding mothers.