Ethnic/racial differences in risk factors and clinical outcomes among patients with amyloidosis

Background: Cardiac amyloidosis is caused by abnormal extracellular deposition of insoluble fibrils in cardiac tissue. It can be fatal when untreated and is often underdiagnosed. Understanding the ethnic/racial differences in risk factors is critical for early diagnosis and treatment to improve clinical outcomes. Methods: We performed a retrospective cross-sectional study utilizing the National Inpatient Sample database from 2015 to 2018 using ICD-10-CM codes. The primary variables of interest were race/ethnicity and amyloidosis subtypes, while the primary outcomes were in-hospital mortality, gastrointestinal bleeding, renal failure, and hospital length-of-stay. Results: Amyloidosis was reported in 0.17% of all hospitalizations (N = 19,678,415). Of these, 0.09% were non-Hispanic whites, 0.04% were non-Hispanic blacks, and 0.02% were Hispanic. Hospitalizations with ATTR amyloidosis subtype were frequently observed in older individuals and males with coronary artery disease, whereas AL amyloidosis subtype was associated with non-Hispanic whites, congestive heart failure, and longer hospital length of stay. Renal failure was associated with non-Hispanic blacks (adjusted relative risk [RR] = 1.31, p < 0.001), Hispanics (RR = 1.08, p = 0.028) and had an increased risk of mortality. Similarly, the hospital length of stay was longer with non-Hispanic blacks (RR = 1.19, p < 0.001) and Hispanics (RR = 1.05, p = 0.03) compared to non-Hispanic whites. Hispanics had a reduced risk of mortality (RR = 0.77, p = 0.028) compared to non-Hispanic whites and non-Hispanic blacks, and no significant difference in mortality was seen between non-Hispanic whites and non-Hispanic blacks (RR = 1.00, p = 0.963). Conclusions: Our findings highlight significant ethnic/racial differences in risk factors and outcomes among amyloidosis-related US hospitalizations that can possibly be used for early detection, treatment, and better clinical outcomes.