The Effect of Existing Heart Allocation Criteria on Transplant Outcomes Globally: A Systematic Review

Abstract

Introduction: Adult and pediatric heart allocation systems worldwide categorize transplant patients based on diverse criteria that impact mortality rates and quality of life. However, there is limited research examining the effectiveness of these systems. This study aims to address this gap by comprehensively comparing different adult heart allocation systems and a pediatric allocation system to identify potential challenges and provide valuable insights for optimizing heart transplant allocation strategies.

Methods: The review was conducted in accordance with the Cochrane Handbook for Systematic Reviews of Interventions. The protocol was registered in PROSPERO (CRD42024513009). An Ovid-MEDLINE and Ovid-Healthstar database search was conducted from January 1, 2024 to January 21, 2024 with relevant search terms. Articles were selected if they used quantitative or qualitative data, were published in the English language, described defined allocation frameworks specific to cardiac surgeries, data was retrieved from hospital-based interventions, and were peer-reviewed. Reviewers screened all articles using the COVIDENCE tool with vetted articles undergoing full-text extraction. The JBI Critical Appraisal tool for systematic reviews was used for risk of bias assessment. A thematic analysis was conducted with a qualitative analysis of intervention effectiveness. The robvis tool assessed the risk of reporting bias.

Results: The database search yielded 630 unique articles. Following screening, 15 articles were selected for analysis. The selected articles described four countries’ national allocation policies; the United Kingdom (n=1), Switzerland (n=1) France (n=2), and the United States of America (n=11). The articles, published between 2016 and 2024, focused on comparing patient outcomes and waitlist times before and after national allocation policy changes.

Discussion: Five articles found improvement in patient outcomes, six articles reported improvement in patient mortality, and six articles found a reduction in waiting time following policy change. The review identifies mixed results regarding the efficacy of various heart allocation frameworks.

Conclusion: The study emphasizes a requirement for further research due to limited access to relevant articles. Additionally, global heart allocation networks are urged to report patient outcomes to allow for a broader, comprehensive analysis of framework efficacy, thereby allowing for a successful informing of policies.