Multimodality Imaging in Eosinophilic Myocarditis: A Rare Cause of Heart Failure.

Eosinophilic myocarditis (EM) is a rare and potentially fatal form of acute myocarditis. Currently, no validated diagnostic criteria exist, and definitive diagnosis relies on endomyocardial biopsy (EMB) not devoid of periprocedural complications. This review aims to explore how a multimodality imaging approach can support early diagnosis, reduce reliance on EMB, enable risk stratification and monitor the response to anti-inflammatory therapy. In particular, while echocardiography provides rapid and useful information in suspected EM, cardiac magnetic resonance (CMR) remains the non-invasive gold standard for diagnosis due to its ability to provide accurate tissue characterization. Moreover, positron emission tomography/computed tomography (PET/CT) and cardiac CT (CCT) may offer valuable insights, particularly when echocardiographic image quality is poor or CMR is contraindicated or unavailable. Based on our experience and current literature, an optimal multimodality imaging approach should reserve EMB only for high-risk or inconclusive cases. Furthermore, this strategy offers complementary information, supporting clinical decisions and optimizing long-term outcomes.