Hi, I'm Alex Fanner. I'm an assistant professor of medicine at the University of Pennsylvania, and I'll be talking about racial and ethnic disparities in peripheral artery disease, with a specific focus on disparities in revascularization for patients with critical limb ischemia. These are data from a couple of smaller studies looking at the rate of primary amputation or amputation without any attempt at revascularization by race. And what you see in both studies is that Black and Hispanic patients are substantially more likely to undergo primary amputation. And what that ultimately means is that non-White patients present with CLI are more likely to undergo amputation. Among patients admitted with CLI, Black, Hispanic, and Native American patients were greater than twofold more likely to undergo amputation during the index admission compared with White patients. Those are the blue lines over there. And patients in the lowest income quartile in rural environments were nearly twofold more likely to undergo amputation compared with patients in the highest income quartile and those living in non-rural environments. So when you add up these differences in revascularization rates, what you see is that in areas of the country with more poor people, more Black people, and that are more rural, these areas have higher rates of amputation. What you're looking at here is a map of U.S. zip codes by amputation rate for 100,000 Medicare beneficiaries. The darkest area of the highest quartile of amputations, about 450 to 7,000 amputations for 100,000 Medicare beneficiaries. And lighter areas represent lower amputation rate zip codes. The national media has done a reasonable job highlighting the disparities in access to revascularization overall PAD care in the South, where there aren't enough vascular specialists and patients may need to travel long distances for care. And when you look at a map like this, it almost looks like the disparities can be explained by lack of cardiovascular specialists in poor rural areas of the U.S., which for important historical reasons have a lot of Black and Native American people. But if you zoom in closer, that's not the case. This is my city, Philadelphia. On the left here is a map of the amputation rates by zip code within Philadelphia County. And one important thing to notice is that I haven't changed the scale here. The dark blue zip code still represents the top quartile nationally amputation rates. And what you see is that even within Philadelphia, there are zip codes with amputation rates that rival rural Alabama. And for those of you not familiar with Philadelphia, I've put a star in my hospital zip code where there are plenty of doctors, but still a top quartile amputation rate nationally. And what the next map show is that these areas of high amputation rates geographically match zip codes to the lowest income and those that are majority Black. But it's not only Philadelphia. We see the same picture in Atlanta, where we all are right now. These are high amputation rate zip codes right next to large well-resourced hospitals, one of them with a star there. And these high amputation rate zip codes tend to overlap with low income and majority Black zip codes. So this raises the question of why we see these disparities. Why are individuals living in poorer communities with greater portions of Black people more likely to have amputation and less likely to undergo limb salvage by revascularization? When we think about why we see these patterns, it's important to remember that revascularization for critical limb ischemia comes toward the end of a long process. Lower extremity PAD progresses slowly and there are a lot of opportunities to interrupt that process. By the time patients need revascularization, there have been a long line of missed opportunities. Moreover, later presentation may make revascularization impossible if PAD has progressed past a certain point. When we look at patients who do undergo revascularization, we see how the care leading up to amputations affects the likelihood of success. Compared with White patients, Black patients undergoing revascularization are more likely to have CLI, undergo emergent or urgent revascularization, and more likely to have advanced disease, the CTO or zero or one patent runoff vessels. On the individual operator level, Black and White patients are treated similarly, at least among patients who do get revascularization, with similar rates of drug-eluting stents and balloons, similar use of IVUS, and similar use of atherectomy. But Black patients who undergo revascularization are more likely to have major amputation in the next year, simply because they have more severe disease when they get to the lab. So getting back to why we see the disparities, one potential ideology is that there are genetic differences between poorer people and Black people that lead them to develop more aggressive atherosclerotic disease that may not be a matter of revascularization leading to amputation. But I'm going to skip past that explanation for two reasons. The first is that it's probably not right, and I point you towards Dorothy Roberts' book, Fatal Intervention, which covers the lack of evidence that genetic differences explain differences in outcomes between White and non-White individuals. And the second is that it's fatalistic and does nothing to help us find solutions to these disparities. Instead, I'll say these disparities in revascularization are at least potentially and significantly due to racism. David Williams, in a really nice review in Annals of Public Health, describes the three ways that racism affects health outcomes. The first is that intrapersonal racism or discrimination causes stress, which leads to increased inflammation and early aging, including vascular aging. Second is that cultural racism or stereotyping leads to individual-level unconscious bias, which leads to inferior care, like not performing revascularization due to concerns about adherence to B12 inhibitors. And the last is structural racism. As Williams describes it, and this is echoed by the AHA's scientific statement from 2020 on healthcare disparities, structural racism affects health outcomes by creating residential racial segregation. This leads to a disproportionate proportion of Black and other non-White people living in areas of concentrated poverty. Areas of concentrated poverty get less investment from the public and private sectors, leading to fewer jobs and educational opportunities, difficulty accessing healthcare, and difficulty practicing healthy behaviors, like eating healthy foods because there are no good grocery stores, or taking medications because there are no pharmacies, or going to the doctor because there are no reliable public transportation to get to appointments. Across a number of clinical conditions, including pregnancy, breast cancer, post-M.I. care, outcomes are worse for individuals living in residentially racially segregated areas. And the patterns of amputation, lower extremity, or revascularization fit into this pattern. So going back to our framework of how patients get to the point they may need amputation, it's easy to see how structural racism may contribute at every level. At the level of primordial prevention, chronic stress, environmental toxins, and food deserts, and no safe place to exercise, prevent these patients from engaging in healthy behaviors. At the primary prevention level, these patients have no access to primary care, no access to pharmacy, and may have no money for co-payments. And finally, once they've progressed to critical limb ischemia, it's difficult to get referrals to vascular specialists, they may have no money for co-payments, and hourly wage jobs make it hard to take time off. So thinking through disparities in revascularization and pediatrics through this lens, what are some solutions? I think we can think about solutions that focus on unconscious bias and cultural racism, and on structural racism. With respect to unconscious bias, there's evidence that consciously recognizing our biases can help us overcome them. Just recognizing disparities in amputation and revascularization rates, as outlined in the talk, can hopefully make us engage with how our unconscious biases may be perpetuating them. When we're faced with poor Black and or rural individuals in need of revascularization, we should ask ourselves whether we're delivering the same care we would be delivering if that patient was richer, white, or urban. With respect to structural racism, these are fixes that may be beyond the capacity of individual operators to change, and may require buy-in from health systems. We need to recognize that current systems cause or perpetuate inequality. No matter where we live and work, these communities are in our backyards. Whether the communities are urban or rural, we need to invest in building systems that bring Black and low socioeconomic status patients into care earlier, before they need to revascularization at all. Things like interfacing with the primary care providers to take care of these patients to make referrals easier, bringing ABI testing to PCP's offices and other settings in these communities, and some of the work that folks in the PAD community are already spearheading to increase knowledge about PAD and how it is managed, and bringing sub-specialty PAD care out of the ivory towers and specialized centers into the communities of patients who suffer from PAD. It won't be easy to reduce these disparities, but it's critical. I thank Sky and the members of this panel for raising these really important issues and look forward to the rest of the session. Thank you.

racial disparities

ethnic disparities

peripheral artery disease

critical limb ischemia

revascularization