Predictors for clinical outcomes:
There was a statistically significant difference in 12-month mortality between the groups (20.7% (n=32) vs 42.8% (n=9), p=0.02). Survival status within the 12-month FU period is graphically depicted by the Kaplan–Meier curve (Figure 2). A Cox-regression analysis showed significantly higher 12-month mortality in group 2 compared to group 1 (HR: 2.33, 95% CI: 1.11 to 4.88, p=0.03) and a multivariate analysis relieved that intraprocedural MPG is the strongest predictor (OR: 1.70, 95% CI: 0.95 to 3.05, p=0.05) for 12-month mortality compared to MGs at another time points, residual MR>II at discharge and recurrent MR>II at FU (Table 4) .
According to multivariate regression analysis, including ROC curve analysis of MGs at three different time points (intraprocedurally, at discharge, and six-month FU) concerning the prediction of adverse functional outcomes (NYHA at FU >II, improvement in walk distance <25%), we found intraprocedural MG to be the strongest predictor for unfavourable clinical outcomes (OR: 1.96, 95%CI: 1.02 to 3.75, p=0.04) with a cut-off value of 3.9 mmHg (specificity of 80% and sensitivity of 63.9%) followed by MG at FU (OR: 1.56, 95%CI: 0.85 to 2.86, p=0.14) with a cut-off value of 2.6 mmHg; however, this finding was without statistical significance(Supplementary Table 1) .
According to the one-way variance analysis of group 1, group 2A, and group 2B concerning adverse functional outcome — higher NYHA functional class (>II) and lower walk distance (improvement <25%) — we found a significant difference between the groups (24% vs 75% vs 55%, p<0.001) (Figure 3A) . Group 2A and 2B showed a somewhat higher 12-month mortality rate than group 1, but without statistical significance (40% vs 33%, vs 29%, p=0.4) (Figure 3B). Remarkably, the worst outcomes – not only functional but also mortality- occurred in group 2A.