C43-09 Cardio-Pulmonary Amyloidosis: A Rare Cause of Dyspnea

Abstract Background Amyloidosis is a disease characterized by the accumulation of protein fibrils across the body leading to a wide range of clinical presentations. It can be primary or secondary, related to chronic infection, inflammation or malignancy. Pulmonary amyloidosis is a rare disorder that occurs either as part of systemic amyloidosis or limited to the lung. Diagnosis is often difficult as clinical and radiological features are vague and variable often with limited treatment options. Case Presentation A 77-year-old man with a past medical history of atrial fibrillation with history of amiodarone use, heart failure, 2nd-degree AV block with pacemaker, prior VSD repair in childhood, interstitial lung disease, coming in with recurrent hypoxic respiratory failures and progressive dyspnea over 18 months. Patient had multiple admissions treated for HF exacerbations and ILD exacerbations with mild response to diuretics and prednisone. Extensive workup done including a high-resolution CT of the chest demonstrating diffuse ground-glass opacities (GGOs), interlobular septal, diffuse bronchial wall thickening without honeycombing or traction bronchiectasis Figure 1. Autoimmune serologies were negative except for rheumatoid factor, and hypersensitivity panels were unremarkable. Pulmonary function tests revealed a mild restrictive pattern. Echocardiogram revealed a normal LVEF, increased LV and RV wall thickness, moderate RV dysfunction, and elevated estimated RVSP consistent with pulmonary hypertension. Right and left heart catheterization showed normal filling pressures, shunt study with minimal shunt from residual VSD. Technetium-99m pyrophosphate scintigraphy demonstrated grade 3 myocardial uptake, and endomyocardial biopsy confirmed wild-type ATTR amyloidosis (TTR gene negative). The CT scan findings persistent despite appropriate diuresis and a prednisone taper. The discordance between extensive radiographic parenchymal disease and only mild physiologic impairment like normal filling pressure and mild restrictive pattern on PFT raised suspicion for pulmonary amyloid deposition rather than primary ILD or amiodarone toxicity. Bronchoscopic biopsy was deferred given frailty and limited clinical utility. Patient was started on acoramidis (Attruby) with reported functional improvement and no oxygen requirement on follow-up. Discussion Pulmonary amyloidosis is common but is mostly asymptomatic. It mimics other diseases like ILD and cancer. Definitive diagnosis requires a tissue biopsy confirming amyloid deposition with congo red staining. Given the wide spectrum of radiographic patterns and overlapping presentations, a multidisciplinary approach is essential to distinguish localized from systemic disease, as treatment strategies and prognosis differ substantially. This abstract is funded by: None