A Systematic Review and Meta-Analysis of Posttransplant Anemia With Overall Mortality and Cardiovascular Outcomes Among Kidney Transplant Recipients

Prog Transplant. 2023 Mar;33(1):78-89 doi: 10.1177/15269248221145046.
Abstract

Introduction: Posttransplant anemia is a common finding after kidney transplantation. A previous meta-analysis reported an association between anemia and graft loss. However, data on cardiovascular outcomes have not yet been reported. Objective: We conducted an updated meta-analysis to examine the association between posttransplant anemia and outcomes after transplantation including cardiovascular mortality in adult kidney transplant recipients. Methods: We comprehensively searched the databases of MEDLINE and EMBASE from inception to November 2021. Data from each study were combined using the random-effects model. Generic inverse variance method of DerSimonian and Laird was employed to calculate the risk ratios and 95% CIs. Results: Seventeen studies from August 2006 to April 2019 were included (16 463 kidney transplantation recipients). Posttransplant anemia was associated with overall mortality (pooled risk ratio = 1.72 [1.39, 2.13], I2 = 56%), graft loss (pooled risk ratio = 2.28 [1.77, 2.93], I2 = 94%), cardiovascular death (pooled risk ratio = 2.06 [1.35, 3.16], I2 = 0%), and cardiovascular events (pooled risk ratio = 1.33 [1.10, 1.61], I2 = 0%). Early anemia (≤6 months), compared with late anemia (>6 months), has higher risk of overall mortality and graft loss with a pooled risk ratio of 2.63 (95% CI 1.79-3.86; I2 = 0%) and 2.96 (95% CI 2.29-3.82; I2 = 0%), respectively. Discussion: In addition to increased risk of graft loss, our updated meta-analysis demonstrated that posttransplant anemia was significantly associated with poor outcomes after kidney transplantation including overall mortality, graft loss, cardiovascular death, and cardiovascular events. Future studies are required to assess the effects of treatment strategies for posttransplant anemia on posttransplant outcomes including cardiovascular mortality.

CET Conclusion
Reviewer: Reshma Rana Magar, Centre for Evidence in Transplantation, Nuffield Department of Surgical Sciences University of Oxford
Conclusion: This systematic review aimed to assess the impact of posttransplant anaemia (PTA) on overall mortality, graft loss and cardiovascular outcomes. Two electronic databases were used to conduct the literature search. Study screening and data extraction were performed in duplicate. A total of 17 studies were included, all of which were observational cohort studies. The authors concluded that kidney transplant recipients (KTRs) with PTA had a significantly higher risk of overall mortality, graft loss, cardiovascular death and major adverse cardiovascular events (MACE), in comparison to KTRs without PTA. Heterogeneity was significant for some of the outcomes, which the authors speculated were due to differences in demographics, study design, and in definitions and onsets of PTA in each study. No attempts were made to adjust for the effect of confounders in the analysis.
Study Details
Aims: This study aimed to investigate the outcomes associated with posttransplant anaemia (PTA) in kidney transplant recipients.
Interventions: Electronic databases including MEDLINE and EMBASE were searched. Study selection and data extraction were performed by two independent reviewers. The methodological quality of the included studies was assessed using the Newcastle-Ottawa scale.
Participants: 17 studies were included in the review.
Outcomes: The primary outcomes were cardiovascular death and major adverse cardiovascular events (MACE). The secondary outcomes included overall mortality and graft loss.
Follow Up: N/A
Metadata
Funding: No funding was received for this study
Publication type: Meta-Analysis, Review, Systematic Review
Review registration: PROSPERO - CRD42021256762
Organ: Kidney
Language: English
Author email: Poemlarp.Mekraksakit@ttuhsc.edu
MeSH terms: Adult; Humans; Kidney Transplantation; Risk Factors; Anemia; Cardiovascular Diseases; Transplant Recipients