The role of nutritional status, measured by serum albumin, as a prognostic factor in wild-type transthyretin amyloidosis.

BACKGROUND

Nutritional status is a recognised prognostic factor across various diseases, with serum albumin commonly used as a surrogate marker. However, its role in wild-type transthyretin cardiac amyloidosis (ATTRwt) remains underexplored. We aimed to assess the prognostic value of serum albumin at diagnosis in patients with ATTRwt.

METHODS

Retrospective cohort study of ATTRwt patients included in an institutional registry between 2008 and 2023. Serum albumin was measured at diagnosis. The primary outcome was two-year all-cause mortality. A receiver operating characteristic (ROC) curve was used to identify the optimal albumin cut-off. Patients were stratified accordingly, and survival analysis was performed using Kaplan-Meier curves and Cox regression models adjusted for clinically relevant variables.

RESULTS

We included 129 patients (mean age 81 ± 7 years; 86% male). Median serum albumin was 3.97 [3.70-4.20] g/dL. During follow-up, 26% of patients (n = 34) died. The optimal cut-off to predict mortality was 3.88 g/dL (AUC: 0.74; sensitivity: 73.5%; specificity: 75.7%). Patients with serum albumin ≤ 3.88 g/dL (n = 47, 36%) were older and had higher prevalence of heart failure and atrial fibrillation at diagnosis, along with elevated serum creatinine and NT-proBNP levels (all p < .05). Two-year mortality was significantly higher in this group (51% vs. 12%, log-rank p < .001). In multivariable analysis adjusted for age, NT-proBNP, and heart failure at diagnosis, low serum albumin and heart failure remained independently associated with the outcome.

CONCLUSION

Lower serum albumin levels were associated with a higher incidence of all-cause mortality in patients with ATTRwt, underscoring the prognostic value of nutritional status in this population.