Elsevier

The American Journal of Cardiology

Volume 187, 15 January 2023, Pages 164-170
The American Journal of Cardiology

Racial Differences in Atrial Fibrillation Management Between White Patients and Black Patients in Transthyretin Cardiac Amyloid

https://doi.org/10.1016/j.amjcard.2022.10.039Get rights and content

Black patients have higher rates of stroke than White patients. Paradoxically, atrial fibrillation (AF) affects twice as many White patients compared with Black patients. Transthyretin cardiac amyloidosis (ATTR-CA) is associated with both AF and strokes. We hypothesized that although Black patients with ATTR-CA have a lower incidence of AF, when diagnosed with AF, they have increased thromboembolic events. Patients with ATTR-CA (n = 558) at 3 international centers were retrospectively identified. We compared baseline characteristics, presence of AF, outcomes of thromboembolism (stroke, transient ischemic attack, and peripheral embolism), major bleed, and mortality by race. Of all patients, 367 of 488 White patients (75%) were diagnosed with AF compared with 39 of 70 Black patients (56%) (p = 0.001). Black patients with AF had a hazard ratio of 5.78 (95% confidence interval 2.30 to 14.50) for time to first thromboembolic event compared with White patients. There were no racial differences in major bleeding. Black patients with AF more often lacked anticoagulation (p = 0.038) and had higher incidence of labile international normalized ratio (p <0.001). In conclusion, these data suggest that although Black patients with ATTR-CA have lower incidence of AF, they have increased thromboembolic events compared with White patients. These findings may be related to treatment discrepancies, time in therapeutic range for warfarin, and disparities in healthcare.

Section snippets

Methods

This study included a retrospective cohort of 558 patients diagnosed with ATTR-CA. Patients were included from Cardiac Amyloidosis Programs at 3 sites from 2001 to 2020 over 19 years. The cohort is representative of an international sample. The institutional review boards across each site approved the study. This study was a retrospective review that was exempt from written informed consent.

Patients were diagnosed with ATTR-CA based on tissue biopsy or scintigraphy.2 Tissue biopsies were either

Results

The study included 558 patients diagnosed with ATTR-CA, for which Table 1 indicates baseline characteristics. A total of 488 patients (87.5%) identified as White, whereas 70 patients (12.5%) identified as Black. All the Black patients were from the New York City site. There were 367 White patients (75%) diagnosed with AF compared with 39 Black patients (56%) diagnosed with AF at any point (p = 0.001). Of White patients with AF, 326 (89%) were diagnosed with ATTRwt compared with 8 Black patients

Discussion

This study examines the differences in race and outcomes of thromboembolic events in patients with ATTR-CA and AF. The major findings are: (1) in patients with ATTR-CA, Black patients had less prevalent and incident AF than White patients, (2) despite Black patients having a lower prevalence of AF, they had a higher incidence of thromboembolic events than White patients and decreased time to combined thromboembolic event that was at least, in part, mediated by lower use of anticoagulation and

Disclosures

Dr. Maurer reports financial support was provided by National Institute on Aging; reports a relation with Pfizer and Alnylam Pharmaceuticals Inc. that includes: board membership and funding grants; reports a relation with Ackea, Ionis Pharmaceuticals Inc., Prothena Biosciences Inc., Eidos, and GalaxoSmithKline that includes: board membership. Dr. Gonzalez-Lopez reports financial support was provided by Carlos III Health Institute; reports a relation with Pfizer that includes: consulting or

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    Dr. Maurer is funded by K24-AG036778 from the National Institute on Aging, Bethesda, Maryland. This study has been partially funded by Instituto de Salud Carlos III, Madrid, Spain through the projects PI18/0765 (to Dr. Gonzalez-Lopez) and PI20/01379 (to Dr. Garcia-Pavia). These projects are co-funded by European Regional Development Fund/European Social Fund “A way to make Europe”/”Investing in your future.”

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