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

Background: Severe primary mitral regurgitation [degenerative MR (DMR)] is associated with poor outcomes, including cardiac death and hospitalization due to worsening heart failure. However, little information is available regarding the characteristics of moderate DMR and their impacts on prognostic outcome. The aim of the present study was to investigate the prognosis and its determinants in patients with moderate DMR. Methods: We retroactively reviewed 13,700 consecutive patients who underwent transthoracic echocardiography and selected those with moderate DMR but without other underlying cardiac diseases. We assessed the characteristics and event-free rate of patients with moderate DMR compared with those of age-and gender-matched patients with mild or no MR. Results: The cohort included 182 (1%) patients with moderate DMR, and these were compared with 182 age-and gender-matched patients with mild or no MR. During the follow-up period of 1376 +/- 652 days, 30 patients (8%) met the composite endpoint defined as cardiac death or hospitalization due to worsening heart failure. Kaplan-Meier analysis showed that patients with moderate DMR were significantly associated with a poor outcome compared to patients with mild or no MR (log-rank test p < 0.0001). Cox proportional hazard ratio revealed that moderate DMR and paroxysmal atrial fibrillation (PAF) were the independent predictors of the composite endpoint. Conclusions: Patients with moderate DMR and concomitant PAF had a significantly worse outcome compared to those with mild or no MR. Active surveillance and some intervention for patients with PAF and moderate DMR may be required. (C) 2019 Japanese College of Cardiology. Published by Elsevier Ltd. All rights reserved.