Abstract
Heart failure with preserved ejection fraction (HFpEF) represents a major phenotype of heart failure and accounts for over 50% of clinical cases. The complex pathophysiological mechanism involved in HFpEF promotes diagnostic difficulties and limited treatment options, posing a significant challenge in modern cardiology. Conventional imaging methods have significant limitations in comprehensively evaluating the heterogeneous etiologies and key pathological mechanisms of HFpEF. Radionuclide myocardial imaging, through the application of targeted radioactive tracers, enables in vivo, non-invasive quantitative assessment of multiple pathological and physiological processes such as myocardial perfusion, energy metabolism, sympathetic nervous activity, inflammatory responses, and fibrotic progression. Moreover, this technology offers a transformative approach to the precise diagnosis, molecular phenotyping, risk stratification, therapeutic monitoring, and prognostic assessment of HFpEF. Therefore, this review systematically summarizes the latest progress in radionuclide myocardial imaging techniques in diagnosing and treating HFpEF, with a particular focus on analyzing the unique clinical value of this technology in identifying specific etiologies (such as cardiac amyloidosis, cardiac sarcoidosis, and coronary microvascular dysfunction) and elucidating pathological mechanisms (including metabolic remodeling, inflammatory, fibrosis, and alterations in sympathetic innervation). Furthermore, we discuss the future directions of this imaging modality, including the development of novel molecular probes, integration with multimodal imaging techniques, and the application of artificial intelligence-assisted analysis. These innovations are expected to facilitate a paradigm shift from symptom-oriented management to mechanism-targeted therapy, offering new perspectives for the precise classification and clinical management of HFpEF.