Purpose <p>The development of effective treatments for heart failure (HF) often fails due to the lack of preclinical models that closely reflect the native structure and function of the human myocardium. Living myocardial slices (LMS) are ultra-thin sections of heart tissue that have shown to retain the complexity, multicellularity, and function of the innate adult myocardium. The number of studies using LMS for HF research and its underlying diseases has been increasing rapidly over the last few years, mainly due to methodological advances that have prolonged LMS culture. This review summarizes key findings and various applications of LMS in HF research.</p> Recent Findings <p>LMS derived from both animal and human hearts, including end-stage HF explants, donor hearts, or surgical specimens, have increasingly been used to model HF and related cardiac diseases. Moreover, LMS have enabled the study of human-specific responses to potential therapeutic drugs and replicate other drug-related effects, such as cardiotoxicity, as they appear in the clinic. Additionally, they have been used to validate the impact of gene delivery of pro-regenerative targets previously investigated in animal studies. More recently, LMS platforms have also been used to mimic device therapy for HF patients by controlling the mechanical and electrical parameters of LMS in culture.</p> Summary <p>LMS represent a physiologically relevant model that bridges the gap between conventional in vitro systems and in vivo models in HF research. Despite remaining challenges related to tissue availability and culturing, LMS provide a highly translational platform for testing potential treatment strategies and understanding the underlying mechanisms of HF.</p> Graphical Abstract <p></p>