Genetic variation usually prevalent in Black individuals increases risk of heart failure: JAMA

Birmingham: A new study published in the Journal of American Medical Association (JAMA) states that being a carrier of the TTR Val122Ile variation was strongly related to an elevated risk of heart failure among Black persons residing in the United States.

A genetic variation in the TTR gene (rs76992529; Val122Ile) causes misfolding of the tetrameric transthyretin protein complex, which accumulates as extracellular amyloid fibrils and resulting in hereditary transthyretin amyloidosis (population frequency: 3%-4%). As a result, Vibhu Parcha and colleagues carried out this investigation to quantify the correlation of the amyloidogenic Val122Ile TTR variation with the risk of heart failure and death in a large, geographically diversified population of Black people.

Retrospective population-based cohort analysis of 7514 self-identified Black people residing in the United States who took part in the REGARDS research and did not have heart failure at baseline. At the baseline visit, the individuals were enrolled (2003-2007). The majority of outcomes reached the end of their follow-up on December 31, 2018. Data on all-cause mortality were available until December 31, 2020. People with the TTR Val122Ile (rs76992529) genotype were considered for this investigation. The major result was unexpected cardiac failure. cardiovascular mortality, heart failure mortality, and all-cause death were the secondary outcomes. The multivariable Cox proportional hazards regression analysis took genetic ancestry, demographic, clinical, and social variables into account.

The results of this study were as follow:

1. The frequency of the population with TTR Val122Ile mutation was 3.1% among 7514 Black individuals.

2. During a median follow-up of 11.1 years, 535 people had heart failure, with the incidence of heart failure among variant carriers being 15.64 per 1000 person-years compared to 7.16 per 1000 person-years in noncarriers.

3. Heart failure caused the deaths of 141 people, and the incidence of heart failure mortality was 6.11 per 1000 person-years among variant carriers compared to 1.85 per 1000 person-years among noncarriers.

4. 793 people died from cardiovascular causes, with the incidence of cardiovascular mortality among variant carriers being 15.18 per 1000 person-years compared to noncarriers with 10.61 per 1000 person-years.

5. On incident heart failure and secondary outcomes, no significant interaction between TTR variant carrier status and sex was seen.

In conclusion, black US individuals with TTR Val122Ile variation are strongly related to an elevated risk of heart failure.

Reference:

Parcha V, Malla G, Ivin MR, et al. Association of Transthyretin Val122Ile Variant With Incident Heart Failure Among Black Individuals. JAMA. Published online April 04, 2022. doi:10.1001/jama.2022.2896