Challenges in diagnosis and management of severe aortic stenosis with coexisting cardiac amyloidosis: a case report.

BACKGROUND: Transthyretin amyloid cardiomyopathy (ATTR-CM) coexists in up to 15% of elderly patients with severe aortic stenosis (AS), presenting complex diagnostic and therapeutic challenges due to overlapping clinical phenotypes. CASE SUMMARY: An 85-year-old female presented with a 2-month history of heart failure and a previous medical history of total knee replacement. Echocardiography and computed tomography confirmed severe AS, alongside left ventricular hypertrophy out of proportion to the valvular load and an 'apical sparing' strain pattern. Due to the accompanying red flags, a Tc99m-PYP bone scintigraphy was done. This showed a Grade 3 cardiac uptake, and further testing confirmed wild-type ATTR-CM. Given her recent symptom onset, preserved ejection fraction, and high-gradient AS, the Heart Team prioritized transcatheter aortic valve implantation (TAVI). Following a successful procedure, she demonstrated excellent functional recovery at one month, which clinically justified the subsequent initiation of transthyretin stabilizers. DISCUSSION: Concomitant ATTR-CM must be suspected in elderly AS patients presenting with disproportionate hypertrophy or other clinical/imaging 'red flags'. A sequential management strategy-prioritizing TAVI to relieve the haemodynamic bottleneck, followed by clinical reassessment-can effectively identify appropriate candidates for long-term, disease-modifying transthyretin stabilizer therapy.