A Case Report: The Utility of Multimodality Imaging in the Diagnosis of Cardiac Sarcoidosis–Has It Surpassed the Need for a Biopsy?

<b>Background and Clinical Significance:</b> Cardiac sarcoidosis (CS) is a rare but life-threatening disorder, occurring in 2-5% of sarcoidosis cases, though post-mortem studies suggest a higher prevalence. It presents diagnostic challenges due to nonspecific symptoms and the low sensitivity of an endomyocardial biopsy. Recent guidelines emphasize multimodal imaging, such as cardiac magnetic resonance imaging (MRI) and positron emission tomography (PET). Given the risk of heart failure (HF) and arrhythmias, early detection is critical. This case highlights the role of non-invasive imaging in diagnosing CS and guiding treatment. <b>Case Presentation:</b> A 54-year-old female with asthma, hyperlipidemia, a recent diagnosis of anterior uveitis, and familial sarcoidosis presented with dyspnea, chest tightness, and worsening cough. Examination revealed anterior uveitis, erythema nodosum, jugular venous distension, and pedal edema. The electrocardiogram (ECG) demonstrated bifascicular block and premature ventricular contractions (PVCs). The brain natriuretic peptide (BNP) was 975 pg/mL, with the transthoracic echocardiogram revealing a left ventricular ejection fraction of 25-30% with global LV akinesis. Coronary computed tomography angiography (CCTA) excluded coronary artery disease. Cardiac MRI showed late gadolinium enhancement, with PET demonstrating active myocardial inflammation, supporting a >90% probability of CS. Given her clinical trajectory and risk of further decompensation, immunosuppressive therapy was initiated without pursuing a biopsy. A dual-chamber implantable cardioverter defibrillator (ICD) was placed due to risk of ventricular arrhythmias. Bronchoalveolar lavage (BAL) showed a CD4/CD8 ratio of 6.53, reinforcing the diagnosis. She responded well to treatment, with symptom improvement and repeat imaging demonstrating signs of disease remission. <b>Conclusions:</b> This case underscores the growing role of multimodal imaging in CS diagnosis, potentially replacing biopsy in select cases. Early imaging-based diagnosis enabled timely immunosuppression and ICD placement, improving outcomes.