Aortic stenosis and transthyretin cardiac amyloidosis: the chicken or the egg?

Background Aortic stenosis (AS) and transthyretin cardiac amyloidosis (TTR-CA) are both frequent in elderly. The combination of these two diseases has never been investigated. Aims To describe patients with concomitant AS and TTR-CA. Methods Six cardiologic French centres identified retrospectively cases of patients with severe or moderate AS associated with TTR-CA hospitalized during the last 6 years. Results Sixteen patients were included. Mean +/- SD age was 79 +/- 6 years, 81% were men. Sixty per cent were NYHA III-IV, 31% had carpal tunnel syndrome, and 56% had atrial fibrillation. Median (Q1; Q4) NT-proBNP was 4382 ( 2425; 4730) pg/mL and 91% had elevated cardiac troponin level. Eighty-eight per cent had severe AS (n = 14/16), of whom 86% (n = 12) had low-gradient AS. Mean +/- SD interventricular septum thickness was 18 +/- 4 mm. Mean left ventricular ejection fraction and global LS were 50 +/- 13% and -7 +/- 4%, respectively. Diagnosis of TTR-CAwas histologically proven in 38%, and was based on strong cardiac uptake of the tracer at biphosphonate scintigraphy in the rest. Eighty-one per cent had wild-type TTR-CA (n = 13), one had mutated Val122l and 19% did not had genetic test (n = 3). Valve replacement was surgical in 63% and via transcatheter in 13%. Median follow-up in survivors was 33 (16; 65) months. Mortality was of 44% (n = 7) during the whole follow-up period. Conclusions Combination of AS and TTR-CA may occur in elderly patients particularly those with a low-flow low-gradient AS pattern and carries bad prognosis. Diagnosis of TTR-CA in AS is relevant to discuss specific treatment and management.