Ethics approval and consent to participate
All methods were carried out in accordance with relevant guidelines and regulations.
All experimental protocols were approved by a Juntendo University review board in accordance with the Declaration of Helsinki. The ethics application approval number was 17-206.
Informed consent was obtained from all patients and all subjects were over 20 in this study.
Availability of data and materials
The datasets used and/or analysed during the current study are available from the corresponding author on reasonable request. All data generated or analysed during this study are included in this published article
Competing interests
T.K is affiliated with a department endowed by Philips Respironics, ResMed, Teijin Home Healthcare, and Fukuda Denshi. R.N is affiliated with a department endowed by Philips Respironics, ResMed, Teijin Home Healthcare, and Fukuda Denshi. H.D received speakers’ Bureau/Honoraria from Kowa Pharmaceutical Company Ltd., Sanofi-Aventis K.K., Daiichi Sankyo Company., Takeda Pharma ceutical Co., Ltd., Bayer Yakuhin Ltd., MSD K.K., Astellas Pharma Inc., Amgen Astellas BioPharma K.K., AstraZeneca K.K., and research funds from Sanwakagaku Kenkyusho Co., Ltd., Canon Medical Systems Corporation., Kowa Pharmaceutical Company Ltd., Daiichi Sankyo Company., Abbott Medical Japan Co., Ltd., Nihon Medi-Physics Co., Ltd., and Scholarship funds from Abbott Medical Japan Co., Ltd., Nippon Boehringer Ingelheim Co., Ltd., Otsuka Pharmaceutical Co., Ltd., Bayer Yakuhin Ltd., Astellas Pharma Inc., Dainippon Sumitomo Pharma Co., Ltd., Pfizer Co., Ltd., Daiichi Sankyo Company., Takeda Pharma ceutical Co., Ltd., Abbott Medical Japan Co., Ltd., Actelion Pharmaceuticals Ltd., Mitsubishi Tanabe Pharma Corporation., Teijin Pharma Ltd., that are unrelated to this study. All other authors declare no conflict of interest. These funding sources have no other roles in this study. The sponsor had no role in the design of the study, the collection and analysis of the data, or the preparation of the manuscript.
Funding
This study was partly supported by a Grant-in-Aid for Scientific Research (C) [Grant Number 26507010]; JSPS KAKENHI Grant Number JP17K09527, by a Grant-in-Aid for Early Career Scientists Grant Number 18K15904, by a grant to Intractable Respiratory Diseases and Pulmonary Hypertension Research Group, from the Ministry of Health, Labor and Welfare of Japan, No. 20FC1027.
Author contributions:
All authors listed have contributed sufficiently to the project to be included as authors, and all those who are qualified to be authors are listed in the author byline. J.S. and T.K. contributed to designing the study protocol, collecting clinical data, supervising data management and statistical analysis, and drafting the manuscript. H.E., H.W., S.D., H.K., S.T., M.O., T.D., S.O., K.M. contributed to collecting clinical data and reviewing the manuscript. H.D. was involved in supervision and funding acquisition. I attest to the fact that all authors listed on the title page have read the manuscript, attest to the validity and legitimacy of the data and its interpretation, and agree to its submission to BMC cardiovascular disorders.
Acknowledgments
We thank the staff of the Department of Cardiovascular Medicine at Juntendo University. We are also grateful to Yumi Nozawa and Ayako Onodera for their secretarial assistance.