Background: Management of moderate functional mitral regurgitation (FMR) commonly accompanying severe aortic valve (AV) disease is still debatable without specific guidelines. Prognostics accused of postoperative residual mitral regurgitation (MR) in either severe aortic stenosis (AS) or regurgitation (AR) patients are unclear and still questionable.
 Objective: This study was aimed to identify the preoperative predictors of residual MR in patients with severe AS or AR and moderate FMR subjected to aortic valve replacement (AVR) with or without mitral valve (MV) ring annuloplasty repair.
Patients and Methods: This retrospective comparative study involved 87 patients presented with severe AS or AR associated with moderate FMR. Patients were divided into two groups Group < /strong> (I) that included 40 patients who were subjected to AVR only and Group (II) that included 47 patients who were subjected to AVR and MV ring annuloplasty repair.
Results: Significant predictors of overall mortality were atrial fibrillation (AF) (p < /em>=0.011) and residual MR (p < /em>=0.001), of early residual MR were unattempting MV repair (p < /em>=0.007) and prolonged inotropic support (p < /em>=0.015), of late residual MR were postoperative FMR grade 2 or more (p < /em>=0.008), persistent AF (p < /em>=0.046) and left atrial diameter (LAD) >5 cm (p < /em>=0.054), and of development of residual MR among AS populations were AF (p < /em>=0.01), LAD >5 cm (p < /em>=0.002), peak AV gradient p < /em>=0.01) and mean AV gradient p < /em>=0.02) while left ventricular end-systolic diameter (LVESD) p < /em>=0.001) for AR patients.
Conclusion: It could be concluded that the preoperative grade 2 FMR per se is not associated with poor overall survival rate and is not an independent risk factor for postoperative mortality for either AS or AR patients. The postoperative residual MR with its congestive heart failure lethal sequelae is strongly associated with postoperative complications and higher overall mortality. We strongly recommend combined MV ring annuloplasty during AVR when there are any of the forementioned preoperative risk factors.