Juntaro Ashikari, MMSc is the Director of the Investigation and Research Division of the Japan Organ Transplant Network. Mr. Ashikari began his professional career as one of the pioneering procurement transplant coordinators at the Japan Organ Transplant Network in 1996 after graduating from the Masterʼs Degree Course in Medical Science of Osaka University Medical School.
Specializing in the field of organ donation and transplantation, Mr. Ashikari has extensive experience in a wide range of areas, including organ donation consent and family support, donor evaluation, extended criteria donors, donation after circulatory determination of death, organ utilization and allocation, transplant recipient registries, data management, and research in organ donation and transplantation.
Juntaro Ashikari is an active board member and contributor to multiple local medical societies and organizations. He also serves on the local organizing committee for the upcoming International Society for Organ Donation Professionals (ISODP) 2025 Kyoto Conference.
Mr. Ashikari has been granted many government-funded research projects, is a regular speaker at national and international organ and tissue procurement and transplantation conferences, and has authored or co-authored more than 50 scientific abstracts and papers in Japanese and English. Mr. Ashikari has co-edited and co-authored multiple Japanese textbooks for organ procurement coordinators and healthcare professionals, and also has statistically analyzed Japanʼs organ donation and transplantation data in the Japan Organ Transplant Network Organ Donation and Transplantation Databook.
Identifying confounding factors of waitlist mortality and transplant probability for adult heart transplant candidates: A study of the nationwide registry data of Japan
Juntaro Ashikari1, Shinichi Nunoda1,2, Goro Matsumiya3, Tomoyuki Fujita4, Koichiro Kinugawa5, Yasumasa Tsukamoto6, Takeshi Nakatani7, Yoshiki Sawa8.
1Division of Investigation and Research, Japan Organ Transplant Network, Tokyo, Japan; 2Tokyo Women’s Medical University, Tokyo, Japan; 3Chiba University, Chiba, Japan; 4Institute of Science Tokyo, Tokyo, Japan; 5Toyama University, Toyama, Japan; 6National Cerebral and Cardiovascular Center, Osaka, Japan; 7Maki Hospital, Osaka, Japan; 8Osaka Keisatsu Hospital, Osaka, Japan
Introduction: Heart transplant candidates enlisted on the Japan Organ Transplant Network (JOTNW) national waitlist are selected by a recipient selection criterion having two categories for medical urgency. Patients with a ventricular assist device (VAD), other mechanical circulatory support, or continuous intravenous infusion of catecholamines/inotropes in the intensive care unit/cardiac care unit (ICU/CCU) are categorized as Status 1, others as Status 2. This study evaluated and identified the confounding factors in waitlist mortality and transplant probability for adult heart transplant candidates enlisted in Japan.
Method: Anonymized nationwide heart transplant registry data from October 16, 1997 to June 30, 2024 was provided from the JOTNW database with approval of the JOTNW Institutional Review Board (approval number JOTIRB24008). The primary endpoints were all-cause waitlist mortality, and the secondary endpoints were heart transplantation probability. Factors associated with the cumulative incidence of waitlist mortality and transplant probability with a p-value of <0.2 in the univariate Fine-Gray sub-distribution hazard regression model were included in a multivariate model.
Results: Overall heart transplant candidates included in this cohort were 2,441 patients. Heart-lung transplantation candidates (n=17), patients that were never on the waiting list after the revision of the Organ Transplant Act on July 17, 2010 (n=270), patients under 18 years of age at the time of registration (n=327), and patients aged 60 and over at the time of registration (n=172) were excluded. The final cohort included 1,655 patients; 672 patients received heart transplantation (40.6%), 322 patients died on the waitlist (19.5%), 27 patients were delisted (1.6%), and 634 patients were continuously enlisted (38.3%) at the time of observation (June 30, 2024). The median Status 1 wait time and total wait time to heart transplantation were 1,474 ± 505 days and 1,628 ± 746 days respectively. The median wait time at mortality was 943 ± 1,049 days. In the multivariate analysis of the Fine-Gray model, age at registration, blood type AB, congenital heart disease (CHD), valvular heart disease, re-transplantation, cerebral vascular accident (CVA), and change in Status from registration to observation were identified as independent factors for transplant probability. Additionally, age at registration, body mass index, CHD, general ward or intensive care unit/cardiac care unit hospitalization at registration, CVA, change in Status from registration to observation, inotropes at observation, and VAD at observation were identified as independent factors for waitlist mortality.
Conclusion: A serious organ shortage underlies leading to a prolonged wait time of approximately 4 years 6 months to heart transplantation. CHD candidates had a significantly lower probability of transplantation and higher waitlist mortality.
[1] heart transplantation waitlist
[2] waitlist mortality
[3] transplantation probability