Transthyretin Cardiac Amyloidosis in Black Americans

Abstract

Transthyretin (TTR) related cardiac amyloidosis is a progressive infiltrative cardiomyopathy that mimics hypertensive, hypertrophic heart disease and often goes undiagnosed. In the United States, the hereditary form disproportionately afflicts Black Americans, who when compared to Caucasians with wild type TTR amyloidosis, a phenotypically similar condition, present with more advanced disease despite having a non-invasive method for early identification (genetic testing). While reasons for this are unclear, this begs to consider the inadequate access to care, societal factors or a biological basis. In an effort to improve awareness and explore unique characteristics, we review the pathophysiology, epidemiology and therapeutic strategies for TTR amyloidosis, and highlight diagnostic pitfalls and clinical pearls for identifying patients with amyloid heart disease.

Myocardial Contraction Fraction by M-Mode Echocardiography Is Superior to Ejection Fraction in Predicting Mortality in Transthyretin Amyloidosis

“…Low blood pressure has also been associated with greater mortality in patients with light-chain cardiac amyloidosis [16,37] as well as heart failure with reduced ejection fraction [38,39]. Decreases in arterial blood pressure may represent worsening amyloid with lower cardiac stroke volume or even the effects of progressive autonomic dysfunction in effected individuals [40]. …”

Assessing risk for Mendelian disorders in a Bronx population

“…; Shah et al. ) and the APOL1‐related kidney diseases ( APOL1 NM_003661.3:c.1152T>G(p.Ile384Met) and NM_003661.3:c.1024A>G(p.Ser342Gly)), focal segmental glomerulosclerosis, HIV‐associated nephropathy (HIVAN), and hypertension‐associated end stage kidney disease (ESKD) with risks significantly higher for those carrying two risk alleles (Genovese et al. ).…”

“…; Shah et al. ). Liver transplant remains the only potentially curative treatment for transthyretin amyloidosis, and is best accomplished at an early age to reduce perioperative morbidity secondary to cardiac pathology.…”

Epigenomic profiles of African American Transthyretin Val122Ile carriers reveals putatively dysregulated amyloid mechanisms

“…Extensive amyloid deposition seems to resemble hypertrophic cardiomyopathy such as enlargement or wall thickening leading to heart failure and atrial fibrillation 5 . These symptoms often are attributed to other population-prevalent cardiovascular risk factors resulting in underestimation of the clinical penetrance of the Val122Ile 6 . The estimated age of onset for non-cardiac precursor phenotypes for hereditary transthyretin amyloidosis is between 30 to 40 years of age 7 .…”