Peripheral Artery Disease and African Americans: Review of the Literature

Real-World Racial Variation in Treatment and Outcomes Among Patients with Peripheral Artery Disease

INTRODUCTION

Prior studies have found considerable disparities in prevalence and outcomes for patients with peripheral arterial disease (PAD). This study compared rates of diagnostic testing, treatment patterns, and outcomes after diagnosis of PAD among commercially insured Black and White patients in the United States.

METHODS

Optum's de-identified Clinformatics® Data Mart Database (1/2016-6/2021) were used to identify Black and White patients with PAD; first PAD diagnosis was deemed study index date. Baseline demographics, markers of disease severity, and healthcare costs were compared between cohorts. Patterns of medical management and rates of major adverse limb events (MALE; including acute or chronic limb ischemia, lower-limb amputation) and cardiovascular (CV) events (stroke, myocardial infarction) during the available follow-up period were described. Outcomes were compared between cohorts using multinomial logistic regression models, Kaplan-Meier survival analysis, and Cox proportional hazards models.

RESULTS

A total of 669,939 patients were identified, with 454,382 White patients and 96,162 Black patients. Black patients were younger on average (71.8 years vs. 74.2 years), but had higher comorbid burden, concomitant risk factors, and CV medication use at baseline. Prevalence of diagnostic testing, revascularization procedures, and medication use was numerically higher among Black patients. Black patients were also more likely than the White patients to receive medical therapy without a revascularization procedure [adjusted odds ratio with 95% confidence interval (CI) = 1.47 (1.44-1.49)]. However, Black patients with PAD had higher incidence of MALE and CV events than White patients [adjusted hazard ratio for composite event (95% CI) = 1.13, (1.11-1.15)]. Except myocardial infarction, the hazards of individual components of MALE and CV events were also significantly higher among Black patients with PAD.

CONCLUSIONS

Results of this real-world study suggest that Black patients with PAD have higher disease severity at the time of diagnosis and are at increased risk of experiencing adverse outcomes following diagnosis.

Non-esterified fatty acids and risk of peripheral artery disease in older adults: The cardiovascular health study

BACKGROUND AND AIMS

Non-esterified fatty acids have been implicated in the pathogenesis of diabetes and cardiovascular disease. No longitudinal study has assessed their effects on peripheral artery disease (PAD). We determined the relationships between NEFAs and incident clinical PAD and abnormal ankle-brachial index (ABI) in a population-based cohort of older persons.

METHODS

We evaluated 4575 community living participants aged >65 years who underwent measurement of circulating NEFAs in fasting specimens and ABI in 1992-1993. Participants were assessed annually for clinical PAD until 2015 and underwent repeat ABI in 1998-1999. We used Cox proportional hazards regression to model the associations between NEFAs and risk of clinical PAD and logistic regression to model the associations of NEFAs with incident abnormal ABI.

RESULTS

Mean age was 74.8 years, 59% were female, and 17% were Black. NEFAs were associated with higher risk of clinical PAD in unadjusted and adjusted models. The adjusted hazard ratios for incident clinical PAD were 1.51 (95%CI = 1.06-2.13, p = 0.02) across extreme tertiles, and 1.14 (95%CI = 0.99-1.31, p = 0.08) per standard deviation higher NEFA. The corresponding odds ratios for abnormal ABI were 0.95 (95%CI = 0.69-1.32, p = 0.76) across extreme tertiles, and 1.03 (95%CI = 0.89-1.20, p = 0.68) per standard deviation higher NEFA. Relationships appeared similar irrespective of sex, race, or pre-existing cardiovascular disease, but were stronger later than earlier in follow-up.

CONCLUSIONS

Higher serum levels of NEFAs are significantly associated with increased likelihood of clinical PAD over long-term follow-up but not with 6-year decline in ABI. NEFAs may offer a potential target for intervention against clinical PAD.

Factors Associated with Leg Ulcers in Adults with Sickle Cell Disease in Brazil

OBJECTIVE

To define the prevalence of leg ulcers and identify the clinical and laboratory factors associated with leg ulcers in adult participants.

METHODS

The authors conducted a cross-sectional study of 1,109 patients who were 18 years or older with SS or Sβ0-thalassemia genotypes from a Brazilian cohort. Investigators assessed the prevalence of factors associated with leg ulcers from 2013 to 2017.

RESULTS

The prevalence of leg ulcers was 21%. Increasing age (odds ratio [OR], 1.07; range, 1.06-1.09), male sex (OR, 2.03; range, 1.44-2.87), treatment with chronic transfusion therapy (OR, 1.88; range, 1.15-3.03), higher indirect bilirubin levels (OR, 1.48; range, 1.02-2.16), and low hemoglobin levels (OR, 2.17; range, 1.52-3.11) were associated with leg ulcers. Participants who self-reported as Black (OR, 6.75; range, 2.63-21.32), mixed (OR, 3.91; range, 1.55-12.20), and other/unknown (OR, 3.84; range, 1.04-15.24) were more likely to have leg ulcers compared with those who self-reported as White.

CONCLUSIONS

The prevalence of leg ulcers in this Brazilian cohort was higher than the prevalence reported in developed countries. Known factors such as age and male sex were corroborated. The increased bilirubin level and decreased hemoglobin levels among participants with leg ulcers support the hypothesis that hemolysis is correlated with leg ulcer pathogenesis. Self-reported black skin color was an independent predictor of leg ulcers and warrants further study to understand the etiology and implications of this finding.

Racial and Ethnic Disparities in Peripheral Artery Disease

Peripheral artery disease is an obstructive, atherosclerotic disease of the lower extremities causing significant morbidity and mortality. Black Americans are disproportionately affected by this disease while they are also less likely to be diagnosed and promptly treated. The consequences of this disparity can be grim as Black Americans bear the burden of lower extremity amputation resulting from severe peripheral artery disease. The risk factors of peripheral artery disease and how they differentially affect certain groups are discussed in addition to a review of pharmacological and nonpharmacological treatment modalities. The purpose of this review is to highlight health care inequities and provide a review and resource of available recommendations for clinical management of all patients with peripheral artery disease.

Evidence-Based Medical Management of Peripheral Artery Disease

Peripheral artery disease is an atherosclerotic disease of the lower extremities associated with high cardiovascular mortality. Management of this condition may include lifestyle modifications, medical management, endovascular repair, or surgery. The medical approach to peripheral artery disease is multifaceted and includes cholesterol reduction, antiplatelet therapy, anticoagulation, peripheral vasodilators, blood pressure management, exercise therapy, and smoking cessation. Adherence to this regimen can reduce limb-related complications like critical limb ischemia and amputation, as well as systemic complications of atherosclerosis like stroke and myocardial infarction. Relative to coronary artery disease, peripheral artery disease is an undertreated condition. In this article, we explore the evidence behind medical therapies for the management of peripheral artery disease.