Background Aortic stenosis (AS) is common, affecting nearly 3% of those aged over 75. Once symptomatic with severe AS outcomes are poor without intervention. An under-recognised restrictive cardiomyopathy in the elderly is wild-type transthyretin amyloid, with deposits found in up to 25% of those aged over 85 at autopsy. Bone scintigraphy offers a reliable non-invasive method of diagnosis. Dual pathology is likely to be an important disease modifier in the elderly undergoing transcatheter aortic valve implantation (TAVI).

Methods This work forms part of the ATTRact-AS multi-centre study (NCT03029026), which seeks the prevalence of cardiac amyloid in the elderly (aged ≥75) with severe AS referred for TAVI. Participants underwent ^99mTc-3,3-diphosphono-1,2-propanodicarboxylic acid (DPD) scintigraphy prior to TAVI, which was graded using the Perugini scoring system. All DPD-positive patients were referred onto the National Amyloidosis Centre.

Results 125 patients were recruited between October 2016 and January 2018 (aged 86±5 years, 44% male). At baseline the aortic valve peak velocity was 4.19±0.66 m/s, mean gradient 43±15 mmHg and area 0.40±0.11 cm². Left ventricular ejection fraction was 53%±11% and mean septal wall thickness 13±2 mm (range 6–21 mm). DPD scintigraphy was positive in 16 patients (13%, 95% CI: 8% to 20%). Perugini grade was 1 (n=5) and 2 (n=11). In the DPD-positive cohort 44% were male (aged 88±5 years) and those genotyped were all wild-type (n=7).

Discussion We have built on the recently published interim results of the ATTRact-AS study. Our findings from two centres suggest that 13% of elderly patients referred for TAVI with AS have occult cardiac amyloidosis.