Peripheral arterial disease (PAD) is a debilitating vascular disease that disproportionately affects people of lower socioeconomic status (SES) and racial minorities, specifically Black persons.1 PAD patients of low SES and minorities often present later, with more advanced disease, often having no option but major amputation.2,3 Although barriers to adequate access are varied, insurance access has been shown to be one significant barrier.3

Improving access to care by increasing insurance coverage has led to better outcomes as shown by evaluation of the 2006 Massachusetts Healthcare Reform Law (MHRL) and its effects on vascular surgery outcomes.4 In 2010 the Affordable Care Act (ACA) was signed into law and improved healthcare access to millions of uninsured and socioeconomically challenged Americans.5 The ACA, which follows many tenets of the MHRL, provided access in a variety of ways including Medicaid expansion to make more people eligible to receive it, and health insurance market reforms which made private health insurance more affordable.5 The expansion of Medicaid made people that fall below the 138% of the federal poverty level eligible to receive healthcare coverage via Medicaid.5 Many changes were made to the insurance market as a result of the ACA which include preventing insurers from basing premiums on pre-existing conditions, prohibiting limits on benefits, and specifying preventative services without cost-sharing that allowed 76 million people to be eligible for free preventative services.5

The expanded access to healthcare translated into a higher availability of vascular-related care as well, with the rates of vascular surgeries and admission increasing in states that expanded Medicaid under the ACA.6 These rates increased even more among patients of low SES as well as racial minorities in states that expanded Medicaid under the ACA.6 This review article will examine the effects of the ACA and Medicaid expansion on the disparities that exist in PAD and its associated outcomes including revascularization, limb salvage, and major amputation rates.

Multiple studies have established that socioeconomic and racial disparities exist among patients with PAD. Patients of lower SES are almost two-times more likely to develop PAD than those of higher SES.7 Unfortunately, race also independently affects the incidence of PAD with Black persons having higher rates of PAD, and present at a younger age, when compared to Non-Hispanic White (NHW) persons.1,8 Patients with lower SES and racial minorities are less likely to undergo revascularization and tend to have worse outcomes when compared to those of higher SES and NHW persons 8, with lower SES and non-white being associated with a higher risk of major amputation.9 Low SES patients were found to have a 12% increased risk of major amputation compared to high SES patients.10 In the same study, Black persons had almost a 2-fold higher risk of major amputation compared to NHW persons with a hazard ratio of 2.08 independent of other risk factors.10

There are several risk factors that increases the chances of developing PAD or worsen the severity of existing disease, which include hypertension, diabetes mellitus, chronic kidney disease (CKD), and smoking.8 These risk factors have been shown to be more prevalent in people of lower SES and in racial minority groups.8 Black and Hispanic persons are more likely to have uncontrolled hypertension despite being treated with antihypertensive medications, when compared to NHW persons.11 Diabetes also disproportionately affects patients of lower SES and those in racial minority.12 Smoking is more prevalent in people of lower SES and racial minorities specifically Native American persons.13 Uninsured patients, who are more likely to be of low SES and racial minorities, are less likely to stop smoking when compared with insured patients.14 Since diagnosis and management of these PAD risk factors often requires access to primary care, patients of low SES and/or those in racial minority groups often delay care and seek it during an emergency (e.g. hypertensive stroke or diabetic crisis) and often have poorer medical optimization.5 This poor medical optimization is further worsened by the lack of appropriate healthcare access in these marginalized groups.9,10

It has been shown that one of the main barriers to care is inability of the patients to pay for their care and since insurance is the main vehicle of such payment in the US, the availability of insurance affects access to healthcare. Disparity in the lack of private insurance, or any insurance for that matter, independently affects outcomes for patients with PAD. This was shown in several studies where all other predictors of outcomes were controlled for and their effects were taken into account; these included comorbid conditions, smoking status, and severity of presenting disease.9,10 Yet despite these adjustments, lack of insurance remained an independent risk factor for worse outcomes, including a higher rate of major amputation among patients with low SES and racial minorities.9,10 This lack of healthcare access may contribute to the increased severity of PAD comorbidities and worse outcomes among patients of low SES and/ or racial minorities.2,3,8 Furthermore, patients with private insurance were shown to have better outcomes, including lower major amputation rates, compared to patients receiving Medicaid.9 This has been hypothesized to be due to a delayed presentation among patients with Medicaid coverage.9 Studies suggest that, similar to other medical conditions, patients without appropriate access to healthcare often present with more severe PAD needing more urgent/emergent procedures.15

Patients with PAD may appear at various stages of the disease; some may be asymptomatic and only be discovered through screening, while others may present with symptoms ranging from intermittent claudication (IC) to critical limb threatening ischemia (CLTI).16 Studies have found a higher rate of asymptomatic PAD (APAD) among racial minorities, specifically Black persons, when compared to NHW persons which may be linked to the higher prevalence of diabetes in these racial minority groups.8 However, Black persons are more likely than NHW persons to present for management with CLTI.2,8 This may point to a lack of access to the healthcare necessary to detect PAD at an early stage. It may also indicate lower rates of screening offered to Black persons at the primary care level.

Early APAD detection enables for the optimization of modifiable risk factors through medical therapy or lifestyle adjustments. In one meta-analysis, APAD may progress to IC at a rate of 7% over 5 years.16 Subsequently, patients with IC may deteriorate further or progress to CLTI at a rate of 21% over 5 years.16 Early disease diagnosis is crucial, as once CLTI has been established, there is a considerable risk of unfavorable limb outcomes including major amputation, despite limb salvage attempts.17,18 The late presentation of PAD among racial minority groups and those with low SES, might explain the higher rates of major amputation found in these patients (Figure 1).10 However, even among patients who present with claudication, the predicted amputation risk among Black persons and people with low SES is still higher than NHW persons and those with higher SES despite adjusting for comorbidities such as diabetes and CKD (Figure 2).10

Lack of access to adequate care disproportionately affects those with lower SES and racial minorities leading to worse outcome among these patients with PAD.5 Poor and near-poor groups (<138% of the federal poverty level) became eligible to benefit from the expansion of Medicaid under the ACA,5 and the rate of uninsured among minorities significantly decreased after the implementation of the ACA (Figure 3).19 Black persons and Hispanic persons had a significant increase in insurance coverage by 10.1 and 11 percentage-points respectively. This was due to the expansion of Medicaid and/or health insurance market reforms which made private insurance more affordable.5

The ACA offered many people the access to healthcare that they needed, with a decrease in the rate of people who reported difficulty accessing healthcare needs including finding a physician,20 which was similar in effect to the MHRL.21 The increased access to healthcare led to an improvement in the overall health status of people who gained coverage as a result of the ACA, as shown by the 3.4 percentage-point decrease in patients who reported fair or poor health.20 It is important to note that the ACA also helped improve preventative medicine, as the number of preventive visits increased after the implementation of the ACA, particularly among younger adults.22 One example is the increase in screening rates for colorectal as well as breast cancer after the implementation of the ACA.23,24 Further studies are needed to assess the impact of the ACA on screening rates for vascular diseases including PAD.

Medicaid expansion was not uniformly available across the nation, with certain states forgoing one of the major benefits of ACA.25 In states that expanded Medicaid, more revascularization procedures were performed electively which in turn led to better outcomes including a decrease in major adverse limb events (MALE).15 Another study by Eguia et al. showed a higher rate of revascularization procedures done for non-emergent cases which might suggest that patients with PAD are receiving care earlier after Medicaid expansion.6 Patients may have been encouraged to receive care because of a decrease in out of pocket spending after implementation of the ACA.6 The higher rates of procedures done for claudication observed in states that expanded Medicaid can be used as a criticism of added insurance under the concept of Moral Hazard, and one can argue this can lead to further harm by performing unnecessary procedures on patients with claudication.26 However, it is important to note that although the expansion of Medicaid led to an increase in admission for patients undergoing vascular surgery there was a decrease in admissions for patient with PAD that require major amputations.6 This is contrasted by the increase in MALE among states that did not expand Medicaid from 30.3% to 34.2% (p-value<0.001).15 Vascular procedures are also more commonly performed for advanced disease or hard indications (such as rest pain or tissue loss) in states that expanded Medicaid.15 This is particularly true in younger adults who have been some of the main beneficiaries of the ACA especially the Medicaid expansion component.15

The ACA also had an impact on modifying risk factors of PAD. The healthcare reforms implemented in 2010 led to an increase in the diagnosis of both hypertension and diabetes.27 Diagnosis of diabetes increased by 7% in states that expanded Medicaid, while there was nonsignificant increase of 25% in the diagnosis of hypertension.27 This may reflect an increased access to care for patients who may have had these diseases for years but could not afford healthcare.27 For diabetes, an estimated 2.3 million patients who were undiagnosed in 2010 may have benefited from zero cost diabetes screening.28 Smoking cessation treatments also improved after the implementation of the ACA which had four sections that addressed the expansion of treatments.29 (1) All approved pharmacotherapy and counseling were made available with no cost sharing for pregnant women. (2) Medicaid programs that fully cover smoking-cessation treatment were offered an increase in the Federal Medical Assistance Percentage. The ACA also prohibited the exclusion of smoking-cessation treatments from (3) enrollees through Medicaid formulary requirements and (4) Medicaid expansion enrollees.29 and although Medicaid patients are more often smokers compared to non-Medicaid patients, they are also more likely to use smoking cessation treatments.29

Increasing access to healthcare would encourage patients to seek help earlier rather than delay care because of lack of insurance or funds, which in turn may lead to earlier diagnosis and management of less severe arterial disease. This has been the effect of the ACA, as the proportion of adults who avoided necessary care as a result of cost decreased from 43% in 2012 to 36% in 2014 after the implementation of the ACA,5 which could explain the increased rates of elective revascularization.6,15 The higher rates of elective procedures translated to a decrease in the rate of MALE in states that expanded Medicaid after the implementation of the ACA (Figure 4).15 The result is an increased rate of limb salvage with lower rates of major amputations after implementing the ACA, with rates of major amputation in Arkansas decreasing by 26% after the expansion of Medicaid.30 It is important to note that there are very few studies that compare major amputation rates in the same state before and after Medicaid expansion and further studies are needed to assess the impact of the ACA on limb salvage per state.