Emerging Insights into Granulomatous and Amyloidogenic Cardiomyopathies

Background: Granulomatous and amyloidogenic cardiomyopathies are infiltrative conditions that can be fatal if left untreated. Among these, cardiac amyloidosis and cardiac sarcoidosis are significant but often underdiagnosed causes of heart failure, each serving as cardiac manifestations of broader systemic diseases. Advancements in imaging techniques and the emergence of novel therapies—particularly for cardiac amyloidosis—have brought these conditions into sharper focus for both clinicians and researchers. Methods: We conducted a comprehensive review of the literature by searching databases including PubMed and Scopus for studies published since 1990 regarding clinical features, diagnostic techniques, and treatment strategies for cardiac amyloidosis and cardiac sarcoidosis. Studies were selected based on relevance to imaging methods, including echocardiography, cardiac magnetic resonance imaging (CMR), positron emission tomography (PET), and technetium-labeled nuclear scintigraphy, as well as treatment modalities for both conditions. Results: Imaging techniques, particularly CMR, technetium-labeled nuclear scan, and PET, were found to be crucial for the early identification and differentiation of cardiac amyloidosis and cardiac sarcoidosis. Distinct late gadolinium enhancement patterns were observed in CMR along with morphological differences, aiding in diagnosis. Technetium-labeled nuclear scintigraphy can definitively distinguish between subtypes of cardiac amyloidosis in the absence of paraproteinemia. Early diagnosis has been shown to significantly improve patient outcomes. Early treatment can reduce morbidity in both cardiomyopathies. Conclusions: Multimodality imaging can help in the early detection of cardiac amyloidosis and cardiac sarcoidosis. Treatment strategies differ substantially: cardiac amyloidosis is primarily managed with disease-modifying therapies for the transthyretin subtype and chemotherapy/stem cell transplant for the AL subtype, while cardiac sarcoidosis is treated with corticosteroids and immunosuppressive drugs to reduce inflammation. Early and accurate diagnosis through advanced imaging techniques is critical to improving outcomes for patients with these conditions.