Received: 14 November 2018
Accepted: 10 June 2019
First Online: 14 June 2019
Ethics approval and consent to participate
: All procedures performed in studies involving human participants were in accordance with the ethical standards of Nagoya Graduate School of Medicine University and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards. A waiver of the informed consent was approved as this study did not provide any intervention to participants. Participants can withdraw at any time without any consequences.
: All authors have agreed to publish this study.
: Akihiro Hirashiki used to belong to a department endowed by Actelion Pharmaceuticals Japan, Ltd. Both Takahisa Kondo, Naoki Okumura and Shiro Adachi belong to a department endowed by Actelion Pharmaceuticals Japan, Ltd.