Transcatheter mitral valve-in-valve replacement (mViV) has emerged as a feasible option to redo surgical mitral valve replacement (rSMVR) for treating dysfunctional mitral valve prostheses. For a study, researchers used the National Inpatient Sample to assess real-world in-hospital mortality, the risk of unfavorable peri-operative outcomes, and mortality predictors between rSMVR and mViV. During the study period, 1,890 patients (78%) had rSMVR, whereas 520 (22%) underwent mViV. After propensity matching, each cohort contained 310 patients. No statistically significant difference in mortality was associated with these operations (odds ratio 1.53; 95% confidence interval 0.67 to 3.45; P=0.31). rSMVR was related to longer hospital stays (13 vs. 7.5 days; P<0.001), higher medical costs ($324,124 vs. $241,147; P<0.001), and more peri-operative problems than mViV. Age over 75 years, cirrhosis, sleep apnea, malnutrition/low body mass index, and obesity were mortality predictors distinct to rSMVR, indicating improved fit for mViV in these populations.