Defence: High-intensity interval training in de novo heart transplant recipients with long-term follow-up

The public defence will be held as a video conference over Zoom.

The defence will follow regular procedure as far as possible, hence it will be open to the public and the audience can ask ex auditorio questions when invited to do so.

Due to copyright reasons, an electronic copy of the thesis must be ordered from the faculty. In order for the faculty to have time to process the order, it must be received by the faculty no later than 2 days prior to the public defence. Orders received later than 2 days before the defence will not be processed. Inquiries regarding the thesis after the public defence must be addressed to the candidate.

Adjudication committee

• First opponent: Professor Ann-Dorthe Olsen Zwisler, University of Southern Denmark
• Second opponent: Coordinator Inger-Lise Aamot Aksetøy, St. Olavs hospital HF
• Third member and chair of the evaluation committee: Professor emeritus Knut Gjesdal, University of Oslo

Chair of the Defence

Professor Emeritus Odd Geiran, University of Oslo

Principal Supervisor

Post-doctor Kari Nytrøen, The National Health Archive of Norway and Oslo University Hospital

Summary

High-intensity interval training (HIT) is an effective method to increase VO2peak in maintenance heart transplant (HTx) recipients. However, there is limited evidence of HIT in the de novo HTx recipients, and the long-term effects of early initiation of HIT after HTx is unknown.

In this study, Rolid and colleagues aimed to investigate the effects of HIT compared to moderate intensity continuous training (MICT) on VO2peak in de novo HTx recipients with a 1-yr and a 3-yr follow-up. In addition, the study aimed to investigate predictors for VO2peak in de novo HTx.

Eighty-one HTx recipients were randomized to either HIT or MICT mean 11 weeks after HTx and were followed-up by local physical therapists for nine months. The study was extended to also perform a 3-yr follow-up of the participants

The primary endpoint was the mean change in VO2peak.  Secondary endpoints were heart rate response, muscle strength, body composition, cardiac function, biomarkers, hemodynamics, endothelial function, health-related quality of life, tolerability, safety, and adverse events.

At 1-yr follow-up there was a significantly higher mean change in VO2peak in the HIT group compared to the MICT group. The difference between groups was 1.8 mL/kg/min which is regarded a clinically meaningful difference. Furthermore, a significant difference between the two groups was found in muscular exercise capacity, anaerobic threshold (AT) and forced expiratory volume. There were no adverse events related to exercise during the intervention period.

At 3-yrs follow-up, there was no longer a statistically significant difference between groups in VO2peak, while difference between groups was still significant with regard to muscular exercise capacity and AT.

HIT, performed de-centralized instead of in the specialist health care setting, was found to be a safe and effective method of exercise in this medically stable cohort of de novo HTx recipients, and showed also some sustainable long-term effects.