Risks factors of adverse clinical outcomes in asymptomatic mitral regurgitation patients with preserved ejection fraction: a systematic review and meta-analysis.

Introduction and objective: Indication for mitral valve (MV) surgery in asymptomatic mitral regurgitation (MR) patients with preserved ejection fraction (EF) remains unclear. This study aims to identify risk factors of adverse clinical outcomes in asymptomatic MR patients with preserved EF for early indication of MV surgery.

Methods: 3 databases were systematically searched to include studies with asymptomatic MR patients with preserved EF. Risk factors of adverse clinical outcomes (composite outcome of MACE and MV surgery indication), mortality, and left ventricular dysfunction (LVD) are pooled with a meta-analysis of random effect model.

Results: A total of 39 observational studies with 9135 asymptomatic moderate to severe MR patients are included. We identified 21 statistically significant risk factors for adverse outcomes. Increased natriuretic peptide, presence of atrial fibrillation, LV GLS > 20%, LVEDD > 35 mm, LVESD > 22 mm, and LAVI > 55 ml/mm², ERO > 55mm², and regurgitation volume > 60 ml (HR 2.21, 2.07, 4.23, 2.98, 4.05, 1.84, 4.02, 3.30, respectively; p-value < 0.05; I² 0-87%) are associated with greater risk of adverse clinical outcome. Risk factors associated with postoperative LVD are the increase of LVEDD, LVESD, and RVSP. Risk factors associated with mortality are increasing STS score and LV GLS.

Conclusion: Several clinical parameters and risk factors can be used to stratify asymptomatic MR patients with preserved ejection fraction who could benefit from early indication for MV surgery.