Racial and Ethnic Disparities in Transthyretin Cardiac Amyloidosis

Abstract

Purpose of review: Transthyretin amyloid cardiomyopathy (ATTR-CM) is a life-threatening disease that disproportionately affects older adults and people of African descent. This review discusses current knowledge regarding racial and ethnic disparities in the diagnosis and management of ATTR-CM.

Recent findings: Historically, ATTR-CM was thought to be a rare cause of heart failure. Recent evidence has shown that ATTR-CM is more common among older adults, men, and people of African descent. In addition, significant geographic variation exists in the identification of amyloid cardiomyopathy. Despite the high burden of ATTR-CM among Black individuals, most clinical data for ATTR-CM are from North America and Europe. Moreover, only a minority of clinical trial participants thus far have been Black patients. In addition to racial differences, socioeconomic disparities may be further compounded by the potentially prohibitive cost and limited accessibility of disease-modifying ATTR therapies.

Summary: ATTR-CM is an important cause of heart failure that disproportionately affects people of African descent. Efforts to promote earlier identification of ATTR-CM in general practice will likely improve clinical outcomes for all groups. Future trials should strive to enroll a higher proportion of Black patients. Furthermore, enhanced efforts are warranted to improve treatment accessibility among racial and ethnic minority groups that may be more likely to be affected by ATTR-CM.

Keywords: Amyloidosis; Cardiac scintigraphy; Cardiomyopathy; Diagnosis; Racial disparities; Transthyretin; Treatment.

Fig. 1

Geographic disparities in reported age-adjusted death rates for amyloidosis in the USA. The triangles represent the location of established amyloidosis referral centers. Reproduced with permission from Alexander, K.M., et al., Geographic Disparities in Reported US Amyloidosis Mortality From 1979 to 2015: Potential Underdetection of Cardiac Amyloidosis. JAMA Cardiol, 2018. 3(9): p. 865–870

Fig. 2

Total number of transthyretin amyloidosis (ATTR) clinical trials by country. The heatmap shows the number of ATTR clinical trials, with darker reds reflecting greater numbers of ongoing trials. Eight recent trials for ATTR cardiomyopathy or neuropathy from a total of 33 countries were included. [, –, –73] There were no trial sites on the continent of Africa

Fig. 3

The leaky pipeline for transthyretin amyloidosis (ATTR) diagnosis and treatment. Only a fraction of patients with ATTR are treated. Cardiomyopathy does not develop in all patients with pathologic mutations due to incomplete penetrance. ATTR cardiomyopathy is frequently identified post-mortem, an untimely diagnosis. Until May 2019, there were no approved therapeutics specifically approved for ATTR cardiomyopathy. At a cost of over $200,000, tafamidis remains unaffordable for some patients with high deductibles and coverage gaps