Received: 17 January 2019
Accepted: 14 March 2019
First Online: 11 April 2019
Ethics approval and consent to participate
: The local institutional review board (Medisch Ethische Toetsingscommissie, University Medical Center Groningen) approved the study (M15.168207 and M16.193856). Written informed consent was obtained from all patients.
: Not applicable.
: TWLS received honoraria from Edwards Lifesciences (Irvine, California, USA) for consulting and for giving lectures. The other authors declare that they have no competing interests.
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