Abstract 14903: Cardiac Structure and Function and Outcome of African-Americans Carrying the Amyloidogenic V122i Transthyretin Mutation: The ARIC (Atherosclerosis Risk in Communities) Study
Background: Almost 4% of African Americans carry an amyloidogenic transthyretin (TTR) mutation, V122I, which usually manifests over the age of 65 years as a restrictive amyloid cardiomyopathy with heart failure (HF). The penetrance of the allele has not been established, although it has been suggested as ≥ 80%. We thus sought to determine the clinical significance of this TTR mutation in a well-defined population.
Methods: Of 3808 African-American patients with available TTR genetic information (115 TTR V122I carriers and 3693 non carriers) from the Atherosclerosis Risk in Communities (ARIC) study, we assessed clinical characteristics and cardiac structure and function of those who underwent echocardiography during the ARIC visit 5 (2011-2013). Mean follow-up was 18±6 years.
Results: There were no major differences in clinical characteristics between carriers and non carriers. However, carriers had slightly larger left ventricular size and reduced diastolic function. Despite similar ejection fraction, systolic function assessed by tissue Doppler imaging and strain imaging were slightly worse in carriers.
Adjusting for age and gender, the presence of the V122I TTR mutation did not increase the risk of all-cause mortality (HR 0.97, 95% CI 0.69-1.35, p=0.85). Mutation carriers showed a 37% increase in risk of incident HF, although statistical significance was not reached (HR 1.37, 95% CI 0.92-2.0, p=0.12).
Conclusions: Despite a relatively high prevalence of the TTR V122I allele in African-Americans, the clinically significant penetrance of the disease over the age of 70 years was low. The presence of the mutation led to a non significant (37%) increase of risk of incident HF.
- © 2013 by American Heart Association, Inc.