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Abstract
Background Participation in regular exercise activities is recommended for patients with chronic heart failure. However, less is known about the effect of exercise in patients with genetic dilated cardiomyopathy (DCM). We sought to examine the effect of vigorousintensity training on physical capacity in patients with DCM caused by truncating titin variants (TTNtv).
Trial design Non-randomised clinical pre-post trial of exercise training.
Methods Individuals with DCM-TTNtv were included from outpatient clinics for inherited cardiac diseases. The trial consisted of 8 weeks of usual care followed by 8 weeks of regular vigorous-intensity cycling exercise, enclosed by three test days. The primary outcome was change in peak oxygen uptake (VO2). Secondary outcomes included change in blood volume, total haemoglobin mass, measures of systolic function and cardiac output/stroke volume during exercise.
Results Thirteen out of 14 included participants (43% women, age 48±11 years, body mass index: 30±6 kg/m2) completed the trial. In the exercise training period, peak VO2 increased by +1.9 mL/kg/min (95% CI +0.9 to +2.9, p=0.002). Compared with usual care, exercise training improved peak VO2 by +2.9 mL/kg/min (95% CI +1.2 to +4.5, p=0.002), corresponding to a 10% increase. Adaptations to exercise training included an increase in resting cardiac output (+0.8 L/min, p=0.042), total blood volume (+713 mL, p<0.001), total haemoglobin mass (+73 g, p<0.001), and improved left ventricular (LV) systolic function (LV ejection fraction: +3.2% (p=0.053) and global longitudinal strain: −2.0% (p=0.044)). No exercise-related adverse events or change in plasma biomarkers of cardiac or skeletal muscle damage were observed.
Conclusions Our study shows that vigorous intensity exercise training improved peak VO2 in patients with DCM-TTNtv. Exercise training was associated with improved LV systolic function and increased blood volume and oxygen carrying capacity. Future research should investigate the effect of long-term exercise in this group.
Trial registration number NCT05180188.
- Cardiomyopathy, Dilated
- Heart Failure
- Cardiac Rehabilitation
Data availability statement
Data are available upon reasonable request. Anonymised data are available on reasonable request. The statistical code for the study can be found on https://github.com/christoffervi/TTNtv-exercise-training.
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Data availability statement
Data are available upon reasonable request. Anonymised data are available on reasonable request. The statistical code for the study can be found on https://github.com/christoffervi/TTNtv-exercise-training.
Footnotes
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Contributors CRV led the conceptualisation and design of the study. JV, HB, AHC, CL, MGS, SVS and IFF assisted in refining the study design and research questions. CRV, MGS, IFF and KHA performed imaging and exercise testing and collected data for the study. CRV and IFF conducted the statistical analysis. All authors assisted in interpreting the data. IFF and CRV wrote the initial drafts of the manuscript, integrating input from all coauthors. All authors critically reviewed and suggested substantial edits to the manuscript’s draft. HB, JV and CRV provided overall leadership for the project coordination and administration. IFF, SVS, HB, JV, CRV, CL and AHC secured funding, supplied relevant equipment and materials for the project, and managed budget allocations. JV, SVS and CRV ensured all ethical approvals were in place. CRV accepts full responsibility for the finished work and/or the conduct of the study, had access to the data and controlled the decision to publish.
Funding The Research Foundations at Rigshospitalet (IFF, CRV and HB), The Capital Region of Denmark (HB), and NordForsk (through the funding to PM Heart (90580, HB)) supported this study.
Competing interests None declared.
Patient and public involvement Patients and/or the public were not involved in the design, or conduct, or reporting or dissemination plans of this research.
Provenance and peer review Not commissioned; externally peer reviewed.
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