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

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.