Long-term outcomes in patients with aortic stenosis and transthyretin cardiac amyloidosis

Abstract

BACKGROUND: The coexistence of aortic stenosis (AS) and transthyretin cardiac amyloidosis (CA) is common. If treated with transcatheter aortic valve replacement (TAVR), patients with the combined phenotype (AS-CA) have a similar survival at 1 year compared to those with lone AS. This study aims to evaluate the long-term outcomes of AS-CA compared to lone AS. METHODS: Using a prospective, multicenter, observational, case-control design, we studied patients with severe AS referred for TAVR. All underwent bone scintigraphy to differentiate between AS-CA and lone AS. Outcomes were compared between the two cohorts. Mortality (all-cause and cardiovascular [CV]) and hospitalization for heart failure (HHF) were captured as clinical endpoints for long-term outcome. RESULTS: 406 patients [84(80-88) years, 50 % female, EuroSCORE-II 4.2 (3.7-5.0)] were recruited, of which 47 (11.6 %) had AS-CA (all transthyretin). Over a follow-up of 5.4 (4.9-5.8) years, 244 (60.1 %) patients died. AS-CA was associated with higher all-cause mortality (crude HR 1.75, 95 % CI 1.24-2.46; log-rank, p = 0.001), which remained significant after multivariate adjustment for clinical confounders (EuroSCORE-II, valve replacement; adjusted HR 1.72, 95 % CI 1.22-2.42; p = 0.002). AS-CA was not associated with CV mortality (log-rank, p = 0.18) or time to first HHF (log-rank, p = 0.43), but the rate of HHF was significantly higher in AS-CA compared to lone AS (129 versus 65 per 1000 patient years, p = 0.022). CONCLUSION: AS-CA is associated with an increased long-term risk of all-cause mortality and rate of hospitalization for heart failure compared to patients with AS. Further studies evaluating the role of CA-specific therapies are warranted in this population.