809 Hedges' g (95% CI) 0.2 (-1.0-1.5) Study Regurgitation models (n=135): P=0.737, I2=90.6% ) COMBINED (n=280): P=0.005, I2=86.7% 0 -7,5 7,5 Hedges' g (95% CI) 4.Study Regurgitation models (n=109): P<0.001, I2=61.0% Shunt models (n=81): P<0.001, I2=88.2% Ruzicka 1993, 7d (n=16) Ruzicka 1993, 28d (n=16) Szabó 2006, 90d (n=18) Bartelds 2011, 30d (n=11) Borgdorff 2012, 28d (n=20) COMBINED (n=190): P<0.001, I2=84.8%