Prognostic Significance of Occult Transthyretin Cardiac Amyloidosis in Patients With Severe Aortic Stenosis Undergoing Surgical Aortic Valve Replacement

Aortic stenosis (AS), a common condition affecting 3% of individuals aged >75 years, leads to heart failure and death unless the valve is replaced. Recently, patients with concomitant degenerative AS and transthyretin-related cardiac amyloidosis have been reported. One prospective study investigated the coexistence of cardiac amyloidosis in elderly patients with AS who were referred for an aortic valve replacement (surgical or transcatheter), by using echocardiography, Tc-3, 3-diphosphono-1, 2-propanodicarboxylic acid scintigraphy, and endomyocardial biopsy, but no cardiac magnetic resonance; 5 of the 43 patients were diagnosed with wild-type transthyretin-related amyloidosis (wtATTR). Of the 5 patients with wtATTR, only 1 was female (median age, 84 years; range, 76–90 years), and all had advanced heart failure (New York Heart Association III/IV). One retrospective analysis included 171 patients with wtATTR, on the basis of clinical presentation, in addition to endomyocardial biopsy, cardiac magnetic resonance, echocardiography with an apical sparing strain pattern, and Tc-pyrophosphate scintigraphy; 27 were determined to have AS (mean age, 79 years; 70% male). The 2-year mortality rate was not different between patients with and without AS, suggesting that the mortality in patients with both diseases may be driven by ATTR as opposed to a stenotic aortic valve or its treatment. Another retrospective study reported 16 patients (mean age, 79±6 years; 81% were men) with concomitant AS and transthyretin cardiac amyloidosis (wtATTR, n=13; Val122I, n=1; no genetic test, n=3). After valve replacement (surgical in 63% and via transcatheter in 13%), mortality was 44% (n = 7) during the median 33-month follow-up period. These were small cohort or retrospective studies; larger prospective studies are needed to systematically know the prevalence of wtATTR in patients with severe AS and the mortality of these concomitant diseases after aortic valve replacement. Thus, the frequency of wtATTR cardiac amyloidosis and its mortality in patients with severe AS is a hot topic.