The Trojan Horse - A Case of Transthyretin Cardiac Amyloidosis Diagnosed Via Multi-Modality Imaging

Background: Observational studies have increasingly reported transthyretin amyloid cardiomyopathy (ATTR-CM) as an under-recognized cause of heart failure. We report the first ATTR-CM diagnosed via multi-modality imaging in the Philippines signifying an important milestone in recognition and management of this formerly believed rare disease, locally. Utilization of non-invasive imaging such as echocardiography, cardiac MRI and technetium-99m pyrophosphate scintigraphy (PYP) demonstrates the potential for accurate diagnosis as well as timely and appropriate treatment strategies. Discussion: An 81/M Filipino with a history of carpal tunnel surgery, post-percutaneous coronary intervention (PCI), had three months’ history of refractory heart failure symptoms despite optimized medical treatment. His 2D-echo showed an ejection fraction (EF): 45%-50%, increased left ventricular (LV) posterior wall thickness with mild basal inferior wall hypokinesia and ECG: atrial fibrillation with low voltage. Speckle tracking imaging showed average global longitudinal strain: - 6.5% with cherry-on-top pattern on polar strain map. Cardiac MRI demonstrated diffuse late gadolinium enhancement from endocardial to transmural layers of biventricular and biatrial walls, highly suggestive of cardiac amyloidosis (CA). Light-chain amyloidosis was excluded by negative serum/urine protein electrophoresis/immunofixation. Tc-99m PYP scan revealed greater myocardial-than-bone uptake with a Perugini score 3 and calculated heart-to-contralateral ratio of 1.7. Congestion was controlled with intravenous loop diuretics and he was discharged stable with metoprolol succinate, dapagliflozin and apixaban. At the time of paper submission, he is currently being evaluated for tafamidis treatment. Conclusion: The case highlighted the advantage of multi-modality imaging for noninvasive yet accurate identification of the disease. A tailored approach is required in slowing the disease progression and improving outcomes.