Abstract 15440: Elevated Serum Transthyretin Concentration Found to be Associated With Increased Survival Rate in Hereditary Transthyretin Cardiomyopathy Patients

Abstract

Introduction: Transthyretin amyloid cardiomyopathy (ATTR-CM) results from abnormal deposition of misfolded transthyretin (TTR) deposition in the myocardium. Prior studies have shown an association between lower serum concentrations of TTR with increased mortality in patients with wild-type TTR, suggesting that greater deposition of TTR from the blood into surrounding tissues may reflect increased disease severity. Hypothesis: Serum TTR levels are associated with mortality and HF hospitalization in hATTR patients with Val142Ile mutation. Methods: We conducted a retrospective chart review of patients diagnosed with hATTR-CM at Emory University's Cardiac Amyloidosis Clinic between January 2014 and April 2022 (n=65) and evaluated the association of serum TTR concentration with 1 year survival and 1 year HF hospitalization. We stratified patients on two TTR cut-offs: 18 mg/dL, based on a previous study in a wild-type cohort, and 14.9 mg/dL, the median TTR level in this cohort. Kaplan Meier Survival analysis and Cox proportional hazard modeling examined the association between serum TTR, overall survival, and HF hospitalization, adjusted for troponin-I, age, BMI, BNP, GFR and NYHA class as covariates. Results: Increased serum concentrations of TTR were significantly associated with decreased mortality within 1 year of diagnosis in multivariable models. Adjusted models showed a significant difference between the groups at both cut-offs only when the event was death within 1 year of diagnosis (Cutoff 14.9: HR = 14.02, 95% CI 2.4 - 82.5; cutoff 18: HR 367, 95% CI 35.24-3822.57), but no significant difference for the outcome of HF hospitalization at either cutoff point ( Table ). Conclusions: In our cohort of 65 hATTR patients with the Val142Ile mutation, lower TTR levels at the time of diagnosis were significantly associated with death at 1 year of diagnosis. TTR levels were not significantly associated with HF hospitalization within 1 year of diagnosis.