Received: 25 December 2019
Accepted: 5 August 2020
First Online: 12 August 2020
Ethics approval and consent to participate
: The study protocol conformed to the Declaration of Helsinki and was approved by the ethic committee of Kanagawa Cardiovascular and Respiratory Center, with a waiver of the need for informed consent because of the retrospective study design.
: Not applicable.
: The authors declare that they have no competing interests.