Limitations
There are several important limitations to this study. It is a retrospective single institution study and the techniques used in the repair in this study are largely surgeon’s preference which might be different from institution to another. Even though, mortality analysis was adjusted for comorbid conditions and acuity of the surgery, it is still possible that the results are affected by factors that were not accounted for in the analysis. Not all mitral valve repair techniques were included in this analysis due to rare use. The effect of concomitant surgery (CABG or other valve) and the type of mitral valve replacement (biologic vs mechanical) were not assessed in this analysis, because they are out of the scope of the study.