Prognostic significance of moderate primary mitral regurgitation and concomitant paroxysmal atrial fibrillation.

•Moderate mitral regurgitation (MR) patients have worse outcomes than those with mild MR.•Patients with moderate MR had more paroxysmal and persistent atrial fibrillation.•Moderate MR was an independent determinant of the composite primary endpoint.•Paroxysmal atrial fibrillation was an independent primary endpoint determinant.•Concomitant moderate MR and paroxysmal atrial fibrillation demonstrated the worst prognosis.