Cardiac Magnetic Resonance to Define Myocardial Structure in Obesity-Associated Heart Failure

The global prevalence of both obesity and heart failure continues to rise, and accumulating evidence suggests that their association is likely causal, giving rise to a distinct heart failure phenotype with unique pathophysiologic features compared to non-obese individuals. This review highlights the evolving role of cardiac magnetic resonance imaging (CMR) in the assessment and management of obesity-related heart failure, emphasizing it’s ability to characterize the structural, functional, and tissue-level cardiovascular abnormalities that define this increasingly prevalent condition. Obesity plays a central role in the development of heart failure with preserved ejection fraction (HFpEF), contributing to a unique pathophysiologic cardiovascular phenotype through mechanisms such as myocardial inflammation, diffuse fibrosis, abnormal ventricular loading, and pathologic expansion of adjacent epicardial adipose tissue. These structural and physiologic changes in turn lead to disproportionate atrial and ventricular remodeling, pronounced diastolic dysfunction, cardiac microvascular dysfunction, impaired interventricular mechanics, and elevated cardiac filling pressures. Together, these alterations contribute to the heightened symptom burden, exercise intolerance, and adverse outcomes observed in obese patients with HFpEF. Cardiac magnetic resonance imaging (CMR) provides a non-invasive, comprehensive platform to assess these hemodynamic, structural, and tissue-level abnormalities through an ever-expanding suite of quantitative imaging tools. CMR, with its high spatial resolution, advanced tissue characterization, and comprehensive evaluation of cardiac structure and function, has emerged as a pivotal modality for the diagnosis, phenotyping, and risk stratification of obesity related HFpEF, while also enabling differentiation from important phenocopies and alternative causes of heart failure.