'Masked apical sparing' in wild-type transthyretin cardiac amyloidosis complicated by aortic valve stenosis: a case report.

Background: Wild-type transthyretin cardiac amyloidosis (ATTRwt-CA) may accompany aortic stenosis (AS) in older adults. The coexistence of ATTRwt-CA and AS is associated with increased mortality and a higher incidence of heart failure hospitalization compared to AS alone. Apical sparing, manifested with a preserved apical longitudinal strain by echocardiography, is a cornerstone of diagnosing ATTRwt-CA; however, the role of this parameter in the diagnosis and follow-up of patients with AS complicated with ATTRwt-CA remain. Case summary: We report a case of ATTRwt-CA complicated by AS that was successfully treated with transcatheter aortic valve implantation (TAVI) and tafamidis, a tetramer stabilizer for transthyretin. The patient exhibited a favourable clinical course, highlighting the potential benefit of this combined therapeutic approach. Notably, characteristic features suggestive of apical sparing, which were completely absent before TAVI, emerged 10 months after the interventional afterloading. Discussion: This case indicates the potential benefit of combining tafamidis therapy with TAVI in patients with ATTRwt-CA and AS. Serial assessment of global longitudinal strain (GLS) provides valuable insights into myocardial function beyond the ejection fraction. The absence of the apical sparing sign prior to TAVI and the improvement of apical LS following the interventional afterloading suggest the risk of overlooking the characteristic GLS features of ATTRwt-CA when complicated with AS.