Received: 4 February 2019
Accepted: 6 May 2019
First Online: 24 May 2019
Ethics approval and consent to participate
: This study was performed in accordance with the Declaration of Helsinki and the full protocol was approved by the Institutional Review Board of the Fondazione IRCCS Ca′ Granda Ospedale Maggiore Policlinico, Milan, Italy. All the subjects enrolled in the study gave their written informed consent.
: Not applicable.
: The authors declare that they have no competing interests.
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