A case report of ATTR-amyloidosis following cardiac transplantation: thick ventricles that look alike

Transthyretin (ATTR-) amyloidosis is more prevalent than initially thought. As much as 13% of patients hospitalized with HFpEF may have ATTR-cardiomyopathy (CM). Conversely, heart transplant patients may manifest left ventricular hypertrophy or diastolic dysfunction, especially late after transplantation. We present a case of a 82-year old male heart transplant patient, 31 years following orthotopic heart transplantation. While he was satisfied with his exercise capacity as an octogenarian, several years before he required pacemaker implantation due to 3rd degree AV block, had bilateral carpal tunnel syndrome treated with carpal tunnel release surgery and experienced idiopathic sudden deafness. Based on increasing left ventricular wall thickness during routine follow-up, a diagnosis of ATTR-amyloidosis was suspected. Ultimately, the diagnosis was confirmed non-invasively with a specific scintigraphic exam, while an additional physicochemical stain on an endomyocardial biopsy taken several years before provided pathological proof. We initiated tafamidis, yet stopped this treatment after one month because of gastro-intestinal intolerance. Ultimately, our patient died two years later due to heart failure. Our case shows the long delay between the onset of transthyretin deposition, the presence of clinical signs and the final diagnosis. Echocardiographic findings suggestive for ATTR-CM include left ventricular hypertrophy and diastolic dysfunction, which are both common in heart transplant patients. Yet, ATTR-CM should be considered in the differential diagnosis, especially late after transplantation, in this closely monitored population.