Abstract
Cell therapy, gene therapy, and tissue engineering have been explored as potential strategies to repair or regenerate damaged cardiac tissue. Despite the presence of encouraging preclinical data, clinical trials of regenerative cardiac therapies have yielded mixed results. Our study aimed to investigate the fate of all registered clinical trials within regenerative cardiac medicine, with the purpose of exploring the potential role of publication bias (or trial-completion bias), how published and unpublished research affects the field, and to draw lessons and recommendations for future clinical trials. In this analysis, we show that only a third of all registered trials has yielded results and that a significant number of trials are not completed. Furthermore, we identified significant heterogeneity in study design, study phase, funding, specific therapies used, primary outcome measures and methods of outcome assessment. These observations might hinder the successful translation of cardiac regenerative therapies into clinical practice.