Copyright
©The Author(s) 2018. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Transplantation. Sep 10, 2018; 8(5): 188-197
Published online Sep 10, 2018. doi: 10.5500/wjt.v8.i5.188
Clinical features and determinants of VO2peak in de novo heart transplant recipients
Katrine Rolid, Arne K Andreassen, Marianne Yardley, Elisabeth Bjørkelund, Kristjan Karason, Julia P Wigh, Christian H Dall, Finn Gustafsson, Lars Gullestad, Kari Nytrøen
Katrine Rolid, Arne K Andreassen, Marianne Yardley, Elisabeth Bjørkelund, Lars Gullestad, Kari Nytrøen, Department of Cardiology, Oslo University Hospital, Oslo 0424, Norway
Katrine Rolid, Marianne Yardley, the Norwegian Health Association, Oslo 0307, Norway
Katrine Rolid, Marianne Yardley, Lars Gullestad, Kari Nytrøen, Faculty of Medicine, University of Oslo, Oslo 0316, Norway
Katrine Rolid, Lars Gullestad, Kari Nytrøen, KG Jebsen Center for Cardiac Research, and Center for Heart Failure Research, University of Oslo, Oslo 0316, Norway
Kristjan Karason, Department of Cardiology, Sahlgrenska University Hospital, Gothenburg 41345, Sweden
Julia P Wigh, Department of Physical Therapy, Sahlgrenska University Hospital, Gothenburg 41345, Sweden
Christian H Dall, Department of Cardiology, Bispebjerg University Hospital, Copenhagen 2400, Denmark
Finn Gustafsson, Department of Cardiology, Rigshospitalet University Hospital, Copenhagen 2100, Denmark
Author contributions: Rolid K coordinated the study, collected and analyzed the data and drafted the paper; Andreassen AK contributed to the inclusion of the participants in Norway and in further drafting of the paper; Yardley M and Bjørkelund E contributed to data collection in Norway; Karason K was responsible for the study in Sweden; Wigh JP was responsible for coordination and data collection in Sweden; Dall CH coordinated and collected data in Denmark; Gustafsson F was responsible for the study in Denmark; Gullestad L and Nytrøen K designed the research, were project leaders and participated in further drafting and analyses of the data; all authors contributed to critical revision and editing and approval of the final version.
Supported by the Norwegian Health Association, No. 12906; Scandiatransplant; and the South-Eastern Norway Regional Authority, No. 2013111.
Institutional review board statement: The study was approved by the South-East Regional Committee for medical and health research ethics in Norway and the Committee for medical and health research ethics in Sweden and Denmark.
Clinical trial registration statement: This study is registered at ClinicalTrials.gov. The registration identification number is NCT01796379.
Informed consent statement: All study participants gave their written consent prior to study inclusion.
Conflict-of-interest statement: None of the authors have any conflict of interest to declare.
CONSORT 2010 statement: We have prepared the manuscript according to the CONSORT 2010 statement, where appropriate. A pdf version of the document is uploaded.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Correspondence to: Katrine Rolid, BSc, MSc, Physiotherapist, Department of Cardiology, Oslo University Hospital Rikshospitalet, Postbox 4950 Nydalen, Oslo 0424, Norway.
katrine.rolid@medisin.uio.no
Telephone: +47-41-548328
Received: June 23, 2018
Peer-review started: June 24, 2018
First decision: July 19, 2018
Revised: July 29, 2018
Accepted: August 6, 2018
Article in press: August 6, 2018
Published online: September 10, 2018
Processing time: 76 Days and 20 Hours
AIM
To study exercise capacity and determinants of early peak oxygen consumption (VO2peak) in a cohort of de novo heart transplant (HTx) recipients.
METHODS
To determine possible central (chronotropic responses, cardiopulmonary and hemodynamic function) and peripheral factors (muscular exercise capacity and body composition) predictive of VO2peak, a number of different measurements and tests were performed, as follows: Cardiopulmonary exercise testing (CPET) was performed mean 11 wk after surgery in 81 HTx recipients > 18 years and was measured with breath by breath gas exchange on a treadmill or bicycle ergometer. Metabolic/respiratory measures include VO2peak and VE/VCO2 slope. Additional measures included muscle strength testing, bioelectrical impedance analysis, echocardiography, blood sampling and health-related quality of life. Based on the VO2peak (mL/kg per minute) median value, the study population was divided into two groups defined as a low-capacity group and a high-capacity group. Potential predictors were analyzed using multiple regression analysis with VO2peak (L/min) as the dependent variable.
RESULTS
The mean ± standard deviation (SD) age of the total study population was 49 ± 13 years, and 73% were men. This de novo HTx cohort demonstrated a median VO2peak level of 19.4 mL/kg per min at 11 ± 1.8 wk post-HTx. As compared with the high-capacity group, the low-capacity group exercised for a shorter time, had lower maximal ventilation, O2 pulse, peak heart rate and heart rate reserve, while the VE/VCO2 slope was higher. The low-capacity group had less muscle strength and muscular exercise capacity in comparison with the high-capacity group. In order of importance, O2 pulse, heart rate reserve, muscular exercise capacity, body mass index, gender and age accounted for 84% of the variance in VO2peak (L/min). There were no minor or major serious adverse events during the CPET.
CONCLUSION
Although there is great individual variance among de novo HTx recipients, early VO2peak measures appear to be influenced by both central and peripheral factors.
Core tip: This de novo heart transplant (HTx) cohort demonstrated a median peak oxygen consumption (VO2peak) level of 19.4 mL/kg per min at 11 ± 1.8 wk post-HTx, which is comparable to what is shown in maintenance HTx recipients. VO2peak in this study was determined by both central and peripheral factors. The strongest predictors were O2 pulse, heart rate reserve and muscular exercise capacity. Maximal exercise testing provides valuable information for clinical use and future prognosis and can be safely performed as early as 11 wk post-HTx.
