Risks and benefits of the proposed Amputation Reduction and Compassion (ARC) Act for disadvantaged patients

Racial, ethnic, and socioeconomic disparities in the major risk factors for vascular disease and access to vascular specialist care are well-documented.^1–3 The higher incidence of diabetes, peripheral artery disease (PAD), and related non-traumatic lower extremity amputation among racial and ethnic minority groups, those of low socioeconomic status, and those with poor access to care based on geography (together, referred to below as disadvantaged groups) are particularly pervasive.^1,4–9 Practitioners of vascular surgery and endovascular therapy are uniquely positioned to address health inequities in lower extremity screening, medical management, intervention, and limb preservation among the population of adults at the highest risk for limb loss.

Epidemiology

At least 12 million United States (US) adults are affected by PAD, although this is likely an underestimate.^10–12 The American Heart Association and National Institutes of Health’s 2021 annual report indicates that the lifetime prevalence of PAD in the US is estimated to be 30% for Black adults and 22% for Hispanic adults, compared to 19% for non-Hispanic white adults.¹³ Although diabetic foot ulceration (DFU) is the leading cause of non-traumatic lower extremity amputation worldwide¹⁴, DFU often co-occurs with PAD. Comorbid diabetes and PAD markedly increase the risk of lower extremity amputation compared to diabetes alone.¹⁵ In 2018, an estimated 154,000 adults with diabetes were hospitalized for a lower-extremity amputation (6.1 per 1,000 adults with diabetes), and the crude incidence of amputation in this population is expected to increase with the increasing prevalence of both diabetes and PAD.^16–18

Disparities in major amputation

Compared to their more advantaged counterparts, non-white adults, un- or under-insured adults, and those with low income or who live in resource-deprived neighborhoods have an increased incidence of DFU, are at higher lifetime risk of PAD, are more likely to have advanced PAD at presentation, and are at increased risk of progression from mild or moderate PAD to chronic limb threatening ischemia (CLTI). ¹⁹ PAD, like DFU, is a major cause of lower extremity amputation, and up to 29% of individuals with CLTI will undergo major amputation or die within one year of diagnosis.²⁰ Rates of amputation following a PAD diagnosis are two to four times higher for patients of lower socioeconomic status and among minority patients compared to white patients.^1,6,8,9

Racial, socioeconomic, and insurance coverage disparities in lower extremity amputation reveal systematic failures in the diagnosis and management of lower extremity vascular disease in the US. Language commonly used to describe these disparities often implicates the patient. For example, “delayed presentation,” or an emphasis on “lifestyle factors”, suggests that patient behaviors are the cause of many disparities in major amputation. However, it is important to understand that many disparities among disadvantaged groups are the result of healthcare inequities, including disproportionately poor access to preventive care, failure of non-specialists to recognize signs and symptoms of early PAD, conflicting guidelines for screening, and wide geographic variation in resources and physician practice patterns that affect adherence to screening guidelines. Together, these factors lead to significant delays in the diagnosis of PAD in disadvantaged patients. Without an early diagnosis, affected patients cannot receive appropriate guideline-supported management to prevent disease progression, and their risk of limb threatening disease rises. Efforts are underway at the congressional level to specifically target PAD and inequities associated with its treatment, with the goal of reducing major amputation rates in disadvantaged groups. It is critical that vascular specialists be aware of and involved in these efforts.

The ARC Act

The Amputation Reduction and Compassion (ARC) Act, first introduced in 2020 and reintroduced in 2021,²¹ is a cornerstone of federal legislation aimed at reducing racial, ethnic, socioeconomic, and geographic disparities in lower extremity amputation. The ARC Act notes that “…amputation risks for African Americans living with diabetes are as much as four times higher than the national average… Data analyses have similarly found that Native Americans are more than twice as likely to be subjected to amputation and Hispanics are up to 75 percent more likely to have an amputation.”²² Among the ARC Act’s proposed interventions to reduce disparities in amputation are: 1) enhanced educational resources for primary care providers, 2) the initiation of routine screening for PAD, and 3) limitations on compensation provided for non-traumatic amputations performed without formal vascular assessment. As with all major policy initiatives, it is important to consider the possible benefits and pitfalls of this multi-pronged approach to amputation prevention.

Tenet 1: Educational Resources

The ARC Act’s provision for educational resources has tremendous potential to increase awareness of PAD for physicians and the public. For example, the PAD Awareness, Risk, and Treatment: New Resources for Survival (PARTNERS) program demonstrated that PAD was highly prevalent among primary care practices, yet physician awareness was low, leading to underdiagnosis²³. Simple interventions, such as educating physicians on the importance of a “shoes off” foot exam for patients at high risk for DFU or PAD, have been shown to improve early detection of lower extremity pathology.⁴ Similarly, intensive patient education has yielded a positive short-term reduction in the incidence of DFU.²⁴

Data are limited, however, on the efficacy of population-based educational efforts to reduce the risks of either DFU or PAD.²⁵ In theory, improving public awareness of the early signs and symptoms of PAD or DFU, the potential for these diagnoses to progress to more serious complications, and the ways that early treatment can prevent eventual amputation may allow patients to better advocate for their own early disease detection. However, evidence-based educational tools that demonstrate the efficacy of this approach are needed. Persons without access to primary care, especially those with limited socioeconomic resources, often feel as if there is no choice but to wait until their symptoms—such as claudication or foot wounds—are severe before seeking medical evaluation.^6,26 Persons living in rural communities are an especially vulnerable group not easily reached by healthcare-based outreach. Targeted education in disadvantaged populations will require intentional efforts to reach them, engage them in designing effective educational programs, and most importantly, ensure that formal screening and management recommended by educational tools are truly accessible.

Tenet 2: PAD Screening

Promoting widespread PAD screening is the second major tenet of the ARC Act. The bill would provide coverage for PAD screening tests, such as ankle-brachial index (ABI) measurements and arterial duplex ultrasounds, to at-risk individuals with Medicare, Medicaid, and private health insurance at no out-of-pocket cost.²² In this context, at-risk is defined as individuals who are “(A) 65 years of age or older (B) who is at least 50 years of age but not older than 64 years of age with risk factors for atherosclerosis (such as diabetes mellitus, a history of smoking, hyperlipidemia, and hypertension) or a family history of peripheral artery disease; (C) who is younger than 50 years of age with diabetes mellitus and one additional risk factor for atherosclerosis; or (D) with a known atherosclerotic disease in another vascular bed such as coronary, carotid, subclavian, renal, or mesenteric artery stenosis, or abdominal aortic aneurysm”²² (Figure 1). Screening has the potential to identify patients with PAD earlier in the disease course, improve the benefit of guideline-recommended treatment to prevent disease progression, and reduce disparities in diabetes and PAD-related amputation, but only if it is evidence-based, accessible, and equitably applied. Screening as outlined by the ARC Act fails to address these core requirements.

THE AMPUTATION REDUCATION AND COMPASSION (ARC) ACT.

The main limitation of the ARC Act’s proposal for PAD screening is that evidence-based guidelines for PAD screening do not currently exist. Both the Society for Vascular Surgery (SVS) and the US Preventive Services Task Force have concluded that there is insufficient data to support the routine use of ABI to screen for PAD.^27–29 Although many experts suggest that targeted screening of high-risk individuals based on age, comorbidities, and other risk factors may be of higher yield, prospective data to validate these hypotheses represent a critical knowledge gap. Proponents of mandated universal screening attribute wide and consistently demonstrated geographic variation in PAD care, including diagnostic and therapeutic interventions, to the absence of PAD screening guidelines.^30,31 Pro-screening experts suggest that the lack of universal screening guidelines limits the ability of primary care physicians to uniformly recognize, diagnose, and refer at-risk individuals to a vascular specialist.³⁰ However, screening programs have historically worsened – rather than reduced – disparities in diagnoses. For example, evidence-based screening recommendations for annual foot and vascular exams among adults with diabetes have failed to achieve equal uptake among advantaged and disadvantaged groups. In contrast, racial and geographic disparities in diabetic foot screening have worsened in the past two decades despite national attention to this issue.^32–35

A second limitation to the concept of PAD screening is that screening tests are only accessible to persons who have existing health insurance and access to primary care. The ARC Act’s proposal relies on Medicare, Medicaid, and private health insurance coverage to allow for screening tests in at-risk individuals. However, uninsured persons comprise 12.2% of the US adult population and are among those at the highest risk for non-traumatic lower extremity amputation.^6,36 Furthermore, to obtain these subsidized screening tests, an individual must not only be insured and have access to care, but they must also have access to a practitioner with the time, knowledge, and resources to order or perform the tests. In the current healthcare landscape, it is almost unfathomable that the ARC Act screening tenet as currently designed could be applied equitably.

There is precedent for harm caused by unintentional inequitable disease screening, as modeled by the Screening Abdominal Aortic Aneurysms Very Efficiently (SAAAVE) Act.^37,38 Since the introduction of this act in 2005, numerous studies have shown that Black individuals are captured for abdominal aortic aneurysm (AAA) screening at a lower rate, present with more advanced disease, and have less opportunity for treatment than their white counterparts.^3,39,40 These findings are contrary to the intention of the SAAAVE Act, which was to increase AAA screening in minority patients. Instead, there is broad underutilization and inequitable application of AAA screening in disadvantaged populations.^39,40 The SAAAVE Act experience demonstrates that, without careful application, policies to address healthcare inequities can end up exacerbating them. A constant and explicit emphasis on accessibility and equity is necessary to avoid widening existing disparities in access to high-quality diagnostic and therapeutic care.

A third major limitation to the concept of PAD screening as covered by the ARC Act is the possible consequence of overtreatment, or unnecessary treatment, of mild or moderate disease. Coverage for evidence-based surveillance, medication management, and appropriate application of procedural interventions must be guaranteed for patients who are diagnosed with PAD as part of enhanced screening efforts. Patients diagnosed with PAD without CLTI via the extended ARC Act coverage should undergo guideline-mediated interventions such as lifestyle changes (smoking cessation and exercise therapy) and pharmacotherapy (antiplatelet and statin therapy) prior to any intervention.^29,41 Patients with PAD who are asymptomatic or who have mild or moderate claudication symptoms do not need any additional or invasive interventions. However, overtreatment in the US fee-for-service medical system is increasingly common. We have previously described significant racial and socioeconomic differences in the treatment of claudication with peripheral vascular interventions, with Black patients living in low-income areas undergoing inappropriate early peripheral vascular inventions for claudication at a higher rate than their white counterparts.^42–44 These interventions occur despite well-defined treatment guidelines outlined by the Society for Vascular Surgery and the American Heart Association that recommend only intervening in select patients with claudication who have debilitating symptoms despite engaging in a trial of optimal medical and exercise therapy.^29,41 The proposed broadened PAD screening under the ARC Act will almost certainly increase the prevalence of diagnosed PAD in patients with no or minimal symptoms in the US population. While medical management of affected patients is important, an increase in PAD diagnoses may come with a substantial risk of increasing the use of invasive procedures, many times inappropriately. Most concerning, this risk will likely be much higher in disadvantaged patients.

Tenet 3: Reimbursement

The final tenet of the ARC Act specifically relevant to the vascular community is the proposed denial of reimbursement for non-traumatic amputations that are performed without a preceding formal vascular assessment. Historically, data has shown that disadvantaged patients are more likely than medically similar advantaged patients to undergo primary lower extremity amputation (as opposed to revascularization or other attempts at limb preservation) when presenting with CLTI.^1,6,9,45 In contrast, a recent study using Veterans Health Administration data found that, among veterans who underwent a major lower extremity amputation, Black patients were more likely than their white counterparts to undergo diagnostic studies and equally likely to undergo revascularization attempts prior to their eventual amputation.¹⁰ These VA-based data may suggest that providing equal access to healthcare can improve disparities in treatment algorithms for PAD. Whether a mandated increase in vascular assessment will reduce the rate of lower extremity amputation in socioeconomically disadvantaged individuals without inadvertently increasing healthcare screening costs remains to be determined.

Potential Solutions

While congressional action may be necessary to address disparities in the treatment of PAD, there is unfortunately no consensus on the effectiveness of PAD education or screening to date.⁴⁶ There is uncertain potential for making reimbursement contingent on pre-amputation vascular anatomic diagnostic evaluation to reduce amputation disparities. At face value, elements of the ARC Act share an explicit focus on PAD-related diagnosis and treatment that seem to make common sense, but most lack sufficient evidence to support their widespread implementation.

Based on the above limitations of the pending ARC Act, we suggest a three-fold screening mandate for the vascular specialist community. First, we must work with general practitioners and community partners to design PAD screening interventions that are feasible and cost-effective to implement in the areas of highest need; overburdened primary care settings, low-resource urban and rural areas, and community-based clinics are just a few examples. Second, we must come together to test these screening interventions with large, well-controlled trials in racially, socioeconomically, and geographically diverse populations and care settings. Defining best practices for PAD screening can only be achieved if we engage the communities that we serve. To this end, the roles of vascular specialists as both scientists and ambassadors are equally important. Third, procedural reimbursement for PAD must change such that early or inappropriate invasive interventions for non-limb-threatening PAD (e.g., asymptomatic PAD and claudication) are not rewarded by higher reimbursement than guideline-based medical management. If evidence supports the role of PAD screening in disadvantaged settings, the work of identifying high-risk patients could begin in earnest. Ultimately, we will need to advocate for no-cost screening in all eligible patients, regardless of location or insurance status. It is critical that we be active and intentional in our commitment to reach vulnerable groups that are not easily captured by conventional health system screening, and we must be vigilant in monitoring screening patterns to detect and address inequities as they arise. Each of these proposed approaches should improve limb outcomes for all patients, regardless of race/ethnicity, socioeconomic status, and geography, but patients who already have ready access to preventive and specialist care may be primed to benefit most.

The ARC Act neglects to address the most convincing evidence for legislation as a tool to address disparities: expanding access to health insurance. Declines in DFU and non-traumatic lower extremity amputation, increased utilization of vascular specialty care, and narrowing of racial and socioeconomic gaps in lower extremity complications have been observed in states that adopted the most sweeping Medicare and Medicaid expansion following the introduction of the Affordable Care Act (ACA).^7,26,47 The Medicare expansion and its success provide rare and compelling hope that legislation is capable of mitigating disparities. Legislation that provides specific interventions aimed at reducing disparities in amputation may be more politically attractive than recommitting to Medicaid expansion, but existing evidence suggests that broad legislation that provides primary care and preventive health services to un- and underinsured populations may have the largest impact on amputation rates. Under such a system, primary care and community-based screening for symptoms of early PAD should warrant testing, which may be a more effective strategy than ABI-based screening for asymptomatic patients. ⁴⁶

Conclusion

Our vascular surgery community must lead multidisciplinary efforts to rectify inequities outlined in major amputation. Many readers will note that several of the failures outlined above occur “upstream” before patients ever see a vascular physician. These upstream drivers often delay or prevent appropriate and timely referrals to vascular care. Despite this gap, vascular specialists are well-positioned to contribute to physician education, screening guidelines, and thoughtfully designed legislation that can meaningfully reduce disparities in lower extremity amputation. The Congressional PAD Caucus had the foresight to understand that racial, ethnic, socioeconomic, and geographic disparities are central to disturbing US trends in non-traumatic lower extremity amputation. The ARC Act reflects that taking steps to address PAD and, by extension, DFU early in the disease course for high-risk patients is a crucial initiative for minimizing healthcare disparities. The vascular surgery community must acknowledge the strengths of the PAD Caucus and the ARC Act. We should also meet this initiative with the context, expertise, and evidence required for legislators to weigh the potential benefits and risks of the proposed interventions. By leveraging preventive care under Medicare and Medicaid that has already proven beneficial, advocating for funding to develop evidence-based education and screening tools, and purposefully expanding care to disadvantaged populations with PAD, we may be able to reduce, and ultimately eliminate, the persistent disparities in rates of lower extremity amputations.