# High-intensity interval training and health-related quality of life in de novo heart transplant recipients - results from a randomized controlled trial

PMID: 32807179
Journal: Health and Quality of Life Outcomes
Published: 2020-08-17
Authors: Rolid K, Andreassen AK, Yardley M, Gude E, Bjørkelund E, Authen AR, Grov I, Pettersen KI, Dall CH, Karason K, Broch K, Gullestad L, Nytrøen K

## Question

Does high-intensity interval training improve health-related quality of life more than moderate-intensity continuous training in de novo heart transplant recipients?

## Summary

In recent heart transplant recipients, 9 months of supervised high-intensity interval training and moderate continuous training both improved physical quality-of-life scores. HIIT did not outperform moderate training for the main quality-of-life outcomes, but it produced a larger VO2peak gain and better extensor muscular exercise capacity. Adverse events and rejection rates were similar between groups.

## Population

- Seventy-eight heart transplant recipients were retested after 9 months; baseline groups were HIT n=37 and MICT n=41. Participants were recent de novo heart transplant recipients on immunosuppressive medication, with mean age about 49 years and about 73% men.
- Sample size: 78
- Age: HIT 50 +/- 12; MICT 48 +/- 14 years
- Sex: HIT 28 men/37; MICT 29 men/41
- Fitness level: Recent heart transplant rehabilitation population
- Health status: De novo heart transplant recipients on immunosuppression

## Methodology

- Multicenter randomized controlled trial
- 9 months
- Three Scandinavian transplant centers and supervised local community exercise
- Randomized and controlled study design.

## Protocol

- Supervised HIT after heart transplant; details: Nine months of HIT beginning about 11 +/- 2 weeks after transplant, 2-3 sessions/week. Sessions included 10 min warm-up, 2-4 bouts at 85-95% maximal effort (RPE 16-18) with active rests at RPE 11-13, a goal of 4 x 4 min in the final period, 5 min cool-down, and strength training.
- Modality: Aerobic interval training plus strength training.
- Work intervals: 2-4 intervals, progressing toward 4 min intervals.
- Recovery: Active rest between intervals.
- Sets or repetitions: 2-4 high-intensity bouts per HIT session.
- Intensity: HIT 85-95% maximal effort, RPE 16-18; active rest RPE 11-13.
- Session duration: Warm-up plus interval or continuous aerobic work plus cooldown and strength training.
- Frequency: 2-3.
- Program length: 9 months.
- Progression: HIT goal was 4 x 4 min in the final period.
- Supervised moderate-intensity continuous training; details: MICT standard-care exercise at 60-80% maximal effort (RPE 12-15) for 25 min, with the same warm-up, cool-down, strength training, local supervision, and session frequency.
- Modality: Aerobic interval training plus strength training.
- Work intervals: 2-4 intervals, progressing toward 4 min intervals.
- Recovery: Active rest between intervals.
- Sets or repetitions: 2-4 high-intensity bouts per HIT session.
- Intensity: HIT 85-95% maximal effort, RPE 16-18; active rest RPE 11-13.
- Session duration: Warm-up plus interval or continuous aerobic work plus cooldown and strength training.
- Frequency: 2-3.
- Program length: 9 months.
- Progression: HIT goal was 4 x 4 min in the final period.

## Outcomes

### SF-36 physical component
Status: no clear change
SF-36 Physical Component Summary improved within both groups: HIT 42.2 +/- 7.6 to 48.4 +/- 9.3 and MICT 43.2 +/- 7.7 to 49.0 +/- 8.4; no between-group difference in change (0.6, 95% CI -3.1 to 4.2; p=.762).

95% CI -3

### SF-36 role emotional
Status: mixed
Role Emotional was the only HRQoL between-group difference favoring HIT: change difference 7.2, 95% CI 1.6 to 12.8; p=.012.

95% CI 1

### VO2peak
Status: improved
VO2peak improved more with HIT: +4.8 +/- 4.1 vs +3.1 +/- 3.5 mL/kg/min; difference 1.8, 95% CI 0.1 to 3.5; p=.044.

95% CI 0

### Extensor muscular exercise capacity
Status: improved
Extensor muscular exercise capacity favored HIT with a between-group difference of 464, 95% CI 63 to 863; p=.024.

95% CI 63 to 863

### Anxiety and depression
Status: no clear change
Anxiety and depression scores were low and did not meaningfully change.

## Practical Insights

- In medically supervised rehabilitation, HIIT can be feasible after heart transplant in selected recipients.
- For quality of life, HIIT should not be framed as clearly superior to moderate training based on this trial.
- Fitness gains may be larger with HIIT even when patient-reported physical quality-of-life scores improve similarly.

## Limitations

- Participants had relatively high baseline HRQoL and may represent healthier transplant recipients.
- HRQoL was a secondary/prespecified endpoint and the sample may have been underpowered for some patient-reported outcomes.
- Generic SF-36 may miss transplant-specific quality-of-life changes.
- Findings are not generalizable to unsupervised exercise or high-risk transplant recipients.

## Safety And Adherence

- No between-group differences were found in rejections, serious adverse events, or adverse events.
- Exercise was supervised by health personnel and heart-rate monitored.

## Original Sources

- [PubMed](https://pubmed.ncbi.nlm.nih.gov/32807179/) (pubmed)
- [DOI](https://doi.org/10.1186/s12955-020-01536-4) (doi)
- [PMC full text](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7433122/) (full text)

## Agent Guidance

Preserve the paper-level scope of this note. Do not generalize beyond the population, protocol, measured outcomes, and limitations above.