Screening for Occult Transthyretin Amyloidosis in Patients with Severe Aortic Stenosis and Amyloid Red Flags

Abstract

Aims: The optimal strategy to identify transthyretin-type cardiac amyloidosis (ATTR-CA) in patients with aortic stenosis (AS) is still unclear. This study aimed to investigate if targeted screening for ATTR-CA in patients with severe AS and amyloid red flags is associated with higher detection rates. Methods: The study prospectively enrolled patients ≥65 years with severe AS. Patients who fulfilled ≥1 major (carpal tunnel syndrome (CTS), ruptured biceps tendon, spinal stenosis, N-terminal pro B-type natriuretic peptide ≥1000 pg/mL, cardiac troponin >99th percentile) or ≥2 minor criteria (diastolic dysfunction ≥2 grade/lateral e’ <10 cm/s, atrial fibrillation, atrioventricular conduction disease/pacemaker) received bone scintigraphy and biochemical analysis for light chain amyloidosis. Hypertensive patients (>140/90 mmHg) and those with interventricular septal thickness (IVSd) ≤13 mm were excluded. Results: Overall, 264 patients were screened, of whom 85 were included in the analysis. Tracer uptake Perugini grade ≥1 was detected in nine patients (11%). An endomyocardial biopsy was additionally performed in four of nine patients, yielding a prevalence of 7% (n = 6). All patients with dual AS-ATTR were male. Syncope was more commonly reported in AS-ATTR patients (50% vs. 6%, p = 0.010), who also tended to have more severe hypertrophy (IVSd of 18 vs. 16 mm, p = 0.075). Pericardial effusion and CTS were more common in patients with dual pathology (67% vs. 8%, p < 0.001, and 83% vs. 24%, p = 0.003, respectively). Conclusion: Targeted screening for ATTR-CA in patients with AS and amyloid red flags does not yield higher detection rates than those reported previously in all comers with AS.