Aortic stenosis (AS) is one of the most common causes of valvular heart disease in the US, with severe AS affecting 3% to 4% of individuals older than age 75 years.1 When severe AS is left untreated, nearly half of affected patients die within 1 year of symptom onset.2 Symptoms can include dyspnea on exertion, edema, chest pain, fatigue, and syncope. The American College of Cardiology and the American Heart Association (AHA) have developed evidence-based guidelines to direct the care of patients with AS, including treatment recommendations for surgical repair and surgical or transcatheter valve replacement.3

In 2011, a novel nonsurgical procedure called transcatheter aortic valve replacement (TAVR) was approved; this procedure has transformed the way AS is treated. Prior to this procedure's availability, patients deemed to be at high or prohibitive risk for surgery did not have options for treatment with surgical valve replacement.4 This largely included older adults and individuals with significant comorbidities, such as renal or pulmonary disease. The annual number of TAVR procedures in the US has surpassed that of surgical aortic valve replacements, and the procedure is now also an option for patients deemed to be low surgical risk.4,5

Patients of underrepresented racial and ethnic groups have historically experienced lower rates of recommended treatment for a multitude of cardiac diseases compared with White patients, and severe AS has been no exception.6 Several factors—including access to facilities performing the procedure, lack of physicians offering TAVR, patient mistrust of the healthcare system, and patient lack of knowledge on the mortality of the disease—have been identified as potentially contributing to disparities.2 With the advancement in options for valve replacement with TAVR, treatment for AS would be expected to increase throughout the population and benefit all members of society. This article explores underlying structural racism of the healthcare system and prevalence of AS, treatment rates with TAVR, and TAVR outcomes in underrepresented racial and ethnic groups. Additionally, proposed solutions to reduce this specific disparity, along with recommendations for future areas of research, are discussed.

Structural racism

The AHA defines structural racism as “the normalization and legitimization of an array of dynamics (historical, cultural, institutional and interpersonal) that routinely advantage White people while producing cumulative and chronic adverse outcomes for people of color.”7 Structural racism has been embedded in US society since the beginning of our nation, affecting people of color through limited access to and marginalization of healthcare compared with White people. Treatment for AS is affected by structural racism, and solutions must include both individual and system-wide efforts.8

AS prevalence

The prevalence of AS may be higher among White individuals when compared with Black individuals.9,10 A large study reviewed 272,429 echocardiograms and found that Black patients had lower rates of both severe AS due to degenerative calcific disease and severe AS due to a congenitally bicuspid valve in comparison with White patients, after adjusting for traditional risk factors.10 Known risk factors of AS include congestive heart failure, chronic kidney disease, smoking, hypertension, diabetes mellitus, and obesity.2 There is not a clear understanding of the underlying cause for differences in prevalence; researchers suggest a need for further investigation into genetic, clinical, and environmental factors influencing AS.9-11 Furthermore, a deeper understanding of the effects of social determinants of health, implicit bias, underdiagnosis, and inequity of care on the prevalence of AS must be evaluated in future research.

Rates of treatment and access to TAVR

TAVR procedures are performed at a lower rate among underrepresented racial and ethnic groups compared with White people.12-15 The racial distribution of patients undergoing TAVR between 2011 and 2016 was 91.3% White; 3.8% Black; 3.4% Hispanic; and 1.5% Asian, Pacific Islander, and/or Native American.12 One single-center study found that non-Black patients were significantly more likely to receive TAVR than Black patients (odds ratio [OR] 2.812, confidence interval [CI] 1.007-7.853; P = .048).15 Identified factors influencing the lack of valve replacement include being lost to follow-up, not receiving a cardiology referral, mistrust of the healthcare team, lack of knowledge and understanding of the disease process, and financial constraints.15,16 Additionally, patients may experience difficulty navigating the complex health system or lack transportation to distant TAVR sites during the evaluation process.17

Historically, referral rates for and access to both surgical aortic valve replacement and TAVR have been lower for Black and Hispanic patients than White patients.11,13,15 Between 2012 and 2018, there was significant growth in the number of TAVR programs in metropolitan areas but little in outlying and rural areas.17 Additionally, due to requirements of regulatory bodies for TAVR programs that dictate patient volume and operator experience, significant infrastructure and financial resources are needed to build and sustain programs, which can limit their development in low-income communities.

Morbidity and mortality with TAVR

Researchers have found that Black, White, and Hispanic patients had similar 1-year mortality following TAVR, whereas patients of Asian, Pacific Islander, and/or Native American race had lower 1-year mortality.12 Another study found similar 30-day mortality in Black and White patients (9.8% versus 9.9%; P = .99) and 1-year mortality (19.6% versus 24.3%; P = .458).14 In a large meta-analysis of post-TAVR outcomes, White and Black patients were found to have a similar likelihood of all-cause mortality, stroke, major bleeding, and vascular complications, whereas White patients had lower odds of myocardial infarction (OR 0.65, 95% CI 0.50-0.84; P < .001) and acute kidney injury (OR 0.84, 95% CI 0.74-0.95; P = .01) compared with Black patients.18 Risk-adjusted mortality has proven to be similar in White and Black patients.19,20

Decreasing disparities

A joint effort by both systems and individuals is needed to lessen the disparity in care.8 Improving awareness of this inequity among all stakeholders is a key initiative that should be undertaken moving forward. Categorizing solutions for change into spheres of influence, as identified in Figure 1, can provide the first steps to reducing the disparity.

Figure 1.: Strategies to improve access to TAVR7,8,11

When social determinants of health that negatively affect health are addressed, access to AS treatment can be improved. For example, advocating for the establishment of TAVR programs near disadvantaged populations and ensuring adequate insurance coverage can create opportunities for patients to receive appropriate treatment.8 Developing educational programs for the community to learn about AS, including symptoms and treatment options, is another way to reduce barriers. Furthermore, it is essential for healthcare providers to understand the lived experiences of those affected by structural racism.7 Future research must specifically evaluate how to reduce treatment bias, develop strategies to mitigate structural racism within our systems, and increase wide-reaching stakeholder engagement.

Implications for practice and conclusion

TAVR has expanded the availability of treatment for severe AS with a less invasive modality. However, despite its availability, the disparity in TAVR treatment rates among underserved populations has not lessened over the last decade since the procedure's approval. Lack of access for these groups highlights structural racism in healthcare and contributes to treatment disparity, despite TAVR being a proven, safe option for eligible patients. Awareness of this issue can be a catalyst for change for a multitude of stakeholders, from patients to regulating bodies; can ignite new research; and can allow for improved access to care. When encountering patients with AS, NPs should strive to provide culturally competent communication and education on the disease process, timely and appropriate referrals to specialized valve centers, patient advocacy, and access to safe procedures to ensure equity of care for all.

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