Use of oral anticoagulants in African-American and Caucasian patients with atrial fibrillation: is there a treatment disparity?

Rivaroxaban Versus Warfarin in African American Patients with Nonvalvular Atrial Fibrillation

INTRODUCTION

Black patients are under-represented in randomized trials evaluating oral anticoagulants in non-valvular atrial fibrillation (NVAF). We sought to evaluate the effectiveness and safety of rivaroxaban versus warfarin in African Americans with NVAF.

METHODS

We performed an analysis using Optum® De-Identified Electronic Health Record (EHR) data from 1/1/2012-9/30/2018. We included adult African American patients with a diagnosis of NVAF who were anticoagulant-naïve during the 12-months prior to initiation of rivaroxaban or warfarin. Patients receiving rivaroxaban were 1:1 propensity score matched to warfarin patients. Our primary effectiveness and safety outcomes were the 2-year incidence rates (%/year) of stroke or systemic embolism (SSE) and major bleeding using an intention-to-treat approach. Cohorts were compared using doubly-robust Cox regression and reported as hazard ratios (HRs) with 95% confidence intervals (CIs).

RESULTS

We matched 4102 rivaroxaban and 4102 warfarin users with a median (interquartile range) available follow-up of 2.0 (0.9, 2.0) years. Median CHA2DS2-VASc and HASBLED scores were 3 (2, 4) and 2 (1, 3). Rivaroxaban use was associated with a lower risk of SSE (1.99 versus 2.48, HR = 0.77, 95%CI = 0.60-0.99), ischemic stroke (1.84 versus 2.37, HR = 0.76, 95%CI = 0.59-0.98) and major bleeding (4.22 versus 4.98, HR = 0.84, 95%CI = 0.70-0.99). No differences in intracranial hemorrhage or gastrointestinal bleeding were observed. Neither sensitivity analyses utilizing an on-treatment methodology nor inverse probability-of-treatment weighting showed significant differences in SSE or major bleeding between rivaroxaban and warfarin users.

CONCLUSIONS

Rivaroxaban appeared at least as effective and safe as warfarin when used to manage African American patients with NVAF in routine practice.

Coagulation Status and Venous Thromboembolism Risk in African Americans: A Potential Risk Factor in COVID-19

Severe acute respiratory syndrome coronavirus 2 infection (COVID-19) is known to induce severe inflammation and activation of the coagulation system, resulting in a prothrombotic state. Although inflammatory conditions and organ-specific diseases have been shown to be strong determinants of morbidity and mortality in patients with COVID-19, it is unclear whether preexisting differences in coagulation impact the severity of COVID-19. African Americans have higher rates of COVID-19 infection and disease-related morbidity and mortality. Moreover, African Americans are known to be at a higher risk for thrombotic events due to both biological and socioeconomic factors. In this review, we explore whether differences in baseline coagulation status and medical management of coagulation play an important role in COVID-19 disease severity and contribute to racial disparity trends within COVID-19.

Disparities and Temporal Trends in the Use of Anticoagulation in Patients With Ischemic Stroke and Atrial Fibrillation

Background and Purpose- Ischemic stroke (IS) secondary to atrial fibrillation (AF) is largely preventable with the use of anticoagulation. We sought to identify race-ethnicity and sex disparities with the use of direct oral anticoagulants (DOACs), aspirin, and warfarin in IS patients with AF and to identify temporal trends in the utilization of these medications. Methods- The FLiPER-AF Stroke Study (Florida Puerto Rico Atrial Fibrillation) included 24 040 IS cases enrolled in the Florida-Puerto Rico Collaboration to Reduce Stroke Registry from 2010 to 2016. Multivariable logistic regression models were performed to evaluate the effect of race-ethnicity and sex on utilization of DOACs, aspirin, and warfarin for stroke prevention in AF after adjustment for sociodemographic, hospital, and clinical factors. Results- Among 24 040 IS cases, 54% were women and 10% black, 12% FL-Hispanics, 4% PR-Hispanic, and 74% whites. From 2010 to 2016, DOAC use increased from 0% to 36%, warfarin use decreased from 51% to 17%, and aspirin use remained relatively stable (42%-40%). After adjustment, blacks had higher odds of warfarin (odds ratio, 1.22; 95% CI, 1.07-1.40) prescription at discharge compared with whites. Men had higher rates of aspirin (42.1% versus 38.8%), warfarin (33.6% versus 28.9%), and DOAC (21.3% versus 19.3%) use compared with women. After adjustment, women had lower odds of being discharged on aspirin (odds ratio, 0.92; 95% CI, 0.86-0.98) or warfarin (odds ratio, 0.91; 95% CI, 0.84-0.99). There was no sex difference in use of DOACs. Conclusions- Our study confirmed the increasing use of DOACs, downtrending use of warfarin, whereas aspirin use remained similar over the years. There are sex and race-ethnicity disparities in anticoagulation use in IS patients with AF. It is critical to understand underlying drivers of these disparities to develop better practice strategies for stroke prevention in patients with AF. Clinical Trial Registration- URL: https://www.clinicaltrials.gov . Unique identifier: NCT03627806.

Impact of Race on Outcome of Patients Undergoing Rhythm Control of Atrial Fibrillation

Racial disparities between African American (AA) and White patients have been documented in cardiovascular disease. We investigated whether these disparities exist in patients undergoing rhythm control for atrial fibrillation (AF). 5873 AF patients (241 AA) were followed to the endpoint of death, stroke, or AF recurrence. Invasive procedures for AF rhythm control were examined in both racial groups. Over a mean follow-up time of 40 months, AA patients had a higher adjusted risk of death [HR 1.39, 95% CI 1.00-1.92, p = 0.043] and stroke [HR 1.90, 95% CI 1.13-3.15, p = 0.013] but a lower risk of AF recurrence [HR 0.79, 95% CI 0.63-0.97, p = 0.026]. In addition, AA patients were less likely to undergo AF ablation (p = 0.006) or surgical maze (p = 0.032) procedures compared to White patients, possibly due to the lower rates of AF recurrence. Significant racial disparities exist in the management and outcomes of AA and White patients undergoing rhythm control management for AF.

Racial Differences in Atrial Fibrillation-Related Cardiovascular Disease and Mortality: The Atherosclerosis Risk in Communities (ARIC) Study

IMPORTANCE

The adverse outcomes associated with atrial fibrillation (AF) have been studied in predominantly white cohorts. Racial differences in outcomes associated with AF merit continued investigation.

OBJECTIVE

To evaluate the race-specific associations of AF with stroke, heart failure, coronary heart disease (CHD), and all-cause mortality in a community-based cohort.

DESIGN, SETTING, AND PARTICIPANTS

The Atherosclerosis Risk in Communities (ARIC) Study is a prospective, observational cohort. From 1987 through 1989, the ARIC Study enrolled 15 792 men and women and conducted 4 follow-up examinations (2011-2013) with active surveillance for vital status and hospitalizations. Race was determined by self-report and categorized as white, black, or other.

MAIN OUTCOMES AND MEASURES

Atrial fibrillation (adjudicated using electrocardiograms, hospital discharge codes, and death certificates), stroke, heart failure, CHD, and mortality.

RESULTS

After exclusions, 15 080 participants (mean [SD] age, 54.2 [5.8] years; 8290 women [55.5%]; 3831 black individuals [25.4%]) were included in this analysis. During a mean (SD) follow-up of 20.6 (6.2) years, there were 2348 cases of incident AF. The incident rates of AF per 1000 person-years were 8.1 (95% CI, 7.7-8.5) in white individuals and 5.8 (95% CI, 5.2-6.3) in black individuals. The rates of stroke, heart failure, CHD, and mortality were higher in black individuals with AF than white individuals with AF. The association of AF with these outcomes, estimated with rate differences (rate of the end point in those with AF minus the rate in those without AF per 1000 person-years), also differed by race. The rate difference for stroke in individuals with AF was 10.2 (95% CI, 6.6-13.9) in white individuals and 21.4 (95% CI, 10.2-32.6) in black individuals. For heart failure and CHD, the rate differences were 1.5- to 2.0-fold higher in black individuals than white individuals. White individuals with AF had a rate difference of 55.9 (95% CI, 48.1-63.7) for mortality compared with black individuals, who had a rate difference of 106.0 (95% CI, 86.0-125.9).

CONCLUSIONS AND RELEVANCE

In the prospective ARIC Study, the outcome of AF on the rates of stroke, heart failure, CHD, and mortality was considerably larger in black individuals than white individuals. These results indicate the vulnerability and increased risk in black individuals with AF. Continued investigation of racial differences in AF and its related adverse outcomes are essential to identify and mitigate racial disparities in the treatment of AF.

A comparison of urban and non-urban African American older adults on health-related characteristics

Although residential geographic health disparities have been noted in the previous literature, studies are specifically lacking on intra-group health comparisons of African American older adults by residential geography. The purpose of this study was to determine if health-related characteristics of African American older adults varied by residential geography. Socioeconomic demographics, medical conditions, primary care use, and self-ratings of general health, social activity, and physical activity were compared in a community-dwelling sample of 327 urban and non-urban African American older adults. Urban and non-urban African American older adults were compared on health-related factors. Compared to urban African American older adults, those in non-urban areas had lower incomes, lower self-ratings of general health, social activity, and physical activity, and a higher frequency of arthritis and gastroenterological and urological conditions. Despite poorer general health and medical conditions, non-urban African American older adults were less likely to visit the doctor when needed. Study findings suggest residential geography may be an underappreciated underlying contributing factor to inter-group health disparities between African American and white older adults and not race alone. Therefore, social workers in public health, health care, and clinical settings should be aware of the interaction between race and residential geography.

Pharmacogenetics of novel oral anticoagulants: a review of identified gene variants & future perspectives

Novel oral anticoagulants (NOACs) are becoming a therapy of choice in everyday clinical practice after almost 50 years during which warfarin and related coumarin derivatives were used as the main anticoagulants. Advantages of NOACs over standard anticoagulants include their predictable pharmacodynamics and pharmacokinetics, stable plasma concentrations and less drug-drug and food-drug interactions. However, pharmacogenetics has its place in administration of NOACs, as considerable interindividual variations have been detected. In this review, previous findings in pharmacogenetics of dabigatran, rivaroxaban, apixaban and edoxaban are summarized, along with recommendations for studying genes encoding metabolically important enzymes for four selected NOACs. Future directions include identification of clinically relevant SNPs, and change in optimum dosage for patients who are carriers of significant variants.

Race and Breast Cancer Reconstruction: Is There a Health Care Disparity?

BACKGROUND

Racial disparity continues to be a well-documented problem afflicting contemporary health care. Because the breast is a symbol of femininity, breast reconstruction is critical to mitigating the psychosocial stigma of a breast cancer diagnosis. Whether different races have equitable access to breast reconstruction remains unknown.

METHODS

Two thousand five hundred thirty-three women underwent first-time autologous versus implant-based reconstruction following mastectomy. Information regarding age, smoking, diabetes, obesity, provider, race, pathologic stage, health insurance type, charge to insurance, and socioeconomic status was recorded. Established statistics compared group medians and proportions. A backward-stepwise multivariate logistic regression model identified independent predictors of breast reconstruction type.

RESULTS

Compared with whites, African Americans were more likely to be underinsured (p < 0.01), face a lesser charge for reconstruction (p < 0.01), smoke (p < 0.01), have diabetes (p < 0.01), suffer from obesity (p < 0.01), live in a zip code with a lower median household income (p < 0.01), and undergo autologous-based reconstruction (p = 0.01). On multivariate analysis, only African American race (OR, 2.23; p < 0.01), charge to insurance (OR, 1.00; p < 0.01), and provider (OR, 0.96; p < 0.01) independently predicted type of breast reconstruction, whereas age (OR, 1.02; p = 0.06) and diabetes (OR, 0.48; p = 0.08) did not.

CONCLUSIONS

African American race remains the most clinically significant predictor of autologous breast reconstruction, even after controlling for age, obesity, pathologic stage, health insurance type, charge to patient, socioeconomic status, smoking, and diabetes. Future research may address whether this disparity stems from patient preferences or more profound sociocultural and economic forces, including discrimination.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Risk, III.

Implementing Precision Medicine: The Ethical Challenges

Precision medicine aims to individualize care by understanding differences in genetics, lifestyle, and environment. Pharmacogenomics and cancer genetics represent two promising areas for this approach. Pharmacogenomic tests have the potential to direct drug prescribing to increase safety and effectiveness because individuals vary on a genetic basis in their response to many drugs. Similarly, tests to identify people with an inherited cancer risk can guide prevention. For both, a few tests have entered clinical practice and more are under development. Implementation challenges include the limited evidence base available to guide clinical use and the lack of data from diverse populations. Accordingly, ongoing research should prioritize procedures that enhance the trustworthiness of clinical practice guidelines and create decision support for clinicians and patients that address their needs and accommodate flexibility. Each step involves choices with ethical implications.