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-CA was 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 Val122I 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.