Statistical Analysis
We used SPSS statistical software for all analyses (IBM SPSS Statistics for Macintosh, Version 20.0. Armonk, NY: IBM Corp.) with a two-sided P value of less than 0.05 considered statistically significant. A chi-squared test for association was conducted between MV disease (i.e., DMS or RMS) and each categorical/nominal variable; Fisher’s exact test was used instead if a variable had any expected cell frequencies less than 5. The Shapiro-Wilks test was used to assess the normality of continuous variables. Independent groups of continuous variables were compared using Student’s t-test if the variable had a normal distribution or Mann-Whitney U test if the distribution failed to meet this assumption. Mann-Whitney U tests were used to compare MVACEQ of DMS and RMS while controlling for mean TMPG. DMS patients were stratified based on MVACEQ (≤ 1.0 cm2, 1.0 to 1.5 cm2, > 1.5 cm2) to account for the small sample size, and a Kruskal-Wallis test was used to identify echocardiographic variables significantly impacted by MVACEQ stratification. Echocardiographic variables were assessed using simple linear regression analysis. A receiver operator characteristic (ROC) curve analysis was created to determine the cutoff value of the DMSI value associated with MVACEQ ≤ 1.5 cm2 and MVACEQ ≤ 1.0 cm2.