Advancing Early Detection: The Role of Cardiac Imaging and Early Biomarkers in Immune Checkpoint Inhibitor-Related Myocarditis

The advent of Immune Checkpoint Inhibitors (ICIs) has marked a significant paradigm shift in oncology, leading to improved outcomes in various malignancies. However, this therapeutic advance is affected by the emergence of immune-related adverse events, among which myocarditis, though infrequent, carries a high mortality rate. The nonspecific clinical manifestations and lack of uniform diagnostic criteria frequently result in delayed recognition, underscoring the need for enhanced strategies for early detection. This review synthesizes current evidence on the application of cardiac imaging and circulating biomarkers in the identification of ICI-associated myocarditis. We critically evaluate the diagnostic performance of established imaging modalities such as Cardiac Magnetic Resonance (CMR) and transthoracic echocardiography, while exploring the advanced techniques, including hybrid PET-CMR imaging and myocardial strain analysis. Parallelly, we examine the diagnostic and prognostic utility of conventional and emerging biomarkers, ranging from high-sensitivity troponins and natriuretic peptides to exploratory molecular signatures such as cytokine profiles and exosomal microRNAs. Collectively, these modalities offer the potential for a multimodal, risk-stratified diagnostic framework that may facilitate timely therapeutic intervention. Emphasis is placed on integrating clinical, imaging, and molecular data to inform evidence-based surveillance algorithms. As the oncologic use of ICIs expands, refining our capacity to detect cardiac immune toxicity at a subclinical stage remains imperative to optimizing both oncologic and cardiovascular outcomes.