Early Diagnosis Begets Timely Treatment: Multimodal Imaging Unraveling a Diffuse Amyloid Cardiomyopathy

A case of a 67-year-old male with a history of hypertension, diabetes, and hyperlipidemia presented to the hospital because of chest discomfort, preceded by a gradual onset of diminished exercise tolerance, exertional dyspnea, orthopnea, paroxysmal nocturnal dyspnea, and bilateral lower extremity swelling. An electrocardiogram showed no acute ischemic changes, though he had very mild troponin elevation. Cardiac catheterization showed nonobstructive coronary artery disease. A transthoracic echocardiogram revealed reduced left ventricular systolic function with elevated left ventricular filling pressure. Cardiac magnetic resonance imaging demonstrated abnormal contrast kinetics, consistent with cardiac amyloidosis. A technetium-99m pyrophosphate scan unveiled diffuse cardiac amyloidosis of the transthyretin type. Myocardial biopsy showed amyloid deposition by positive Congo red stain and confirmed by apple-green birefringence on polarized light. He was started on medical therapy for heart failure and coronary artery disease. He was eventually started on an oral transthyretin stabilizer that significantly improved his heart failure symptoms and exercise capacity, with no readmission to the hospital since then. He had been evaluated and deemed a candidate for cardiac transplantation.