Transplant Trial Watch

Cardiorespiratory fitness in kidney transplant recipients compared to patients with kidney failure: a systematic review and meta-analysis.

Theodorakopoulou, M. P., et al.

Transplant International 2021 [record in progress].

This systematic review aimed to compare cardiovascular functional reserve with cardiopulmonary-exercise-testing (CPET) in renal transplant patients versus patients with kidney failure.

Electronic databases, including PubMed/MEDLINE, Web of Science and Scopus were searched. Study selection and data extraction were performed by two independent reviewers. The methodological quality of the included studies was assessed in duplicate using the Newcastle-Ottawa-Scale (NOS) for cohort and case-control studies and the modified NOS for cross-sectional studies.

12 studies were included in the review.

The primary outcome was the assessment of oxygen consumption, either as peak oxygen uptake (VO2peak) during CPET or maximum oxygen uptake (VO2max). Secondary outcomes were separate evaluation of VO2peak; separate evaluation of VO2max and oxygen consumption at anaerobic threshold (VO2AT).


CET Conclusions
This systematic review and meta-analysis explores differences in cardiorespiratory fitness (assessed by cardiopulmonary exercise testing; CPET) between patients with renal failure and those with a functioning transplant. The authors find significantly higher peak VO2 in transplant recipients compared to both HD and peritoneal dialysis patients. There was also significant improvement when comparing patients before and after transplantation. The review is limited by the fact that all included studies are by their nature observational, and there is no mention as to whether there is adjustment for confounders between the cohorts. One would expect a dialysis cohort to include patients unfit for transplantation, and so direct comparison with a transplant cohort without adjustment for comorbidities and cardiovascular risk is likely uninformative. Most analyses had significant heterogeneity that remains unexplained by subgroup analyses.

Trial registration
PROSPERO - CRD42021234487

Funding source
No funding received