Disparities in the Use of Drug-Eluting Coronary Stents by Race, Ethnicity, Payer, and Hospital

Paving a Path to Equity in Cardiorenal Care

Cardiorenal syndrome encompasses a dynamic interplay between cardiovascular and kidney disease, and its prevention requires careful examination of multiple predisposing underlying conditions. The unequal distribution of diabetes, heart failure, hypertension, and kidney disease requires special attention because of the influence of these conditions on cardiorenal disease. Despite growing evidence regarding the benefits of disease-modifying agents (e.g., sodium-glucose cotransporter 2 inhibitors) for cardiovascular, kidney, and metabolic (CKM) disease, significant disparities remain in access to and utilization of these essential therapeutics. Multilevel barriers impeding their use require multisector interventions that address patient, provider, and health system-tailored strategies. Burgeoning literature also describes the critical role of unequal social determinants of health, or the sociopolitical contexts in which people live and work, in cardiorenal risk factors, including heart failure, diabetes, and chronic kidney disease. This review outlines (i) inequality in the burden and treatment of hypertension, type 2 diabetes, and heart failure; (ii) disparities in the use of key disease-modifying therapies for CKM diseases; and (iii) multilevel barriers and solutions to achieve greater pharmacoequity in the use of disease-modifying therapies. In addition, this review provides summative evidence regarding the role of unequal social determinants of health in cardiorenal health disparities, further outlining potential considerations for future research and intervention. As proposed in the 2023 American Heart Association presidential advisory on CKM health, a paradigm shift will be needed to achieve cardiorenal health equity. Through a deeper understanding of CKM health and a commitment to equity in the prevention, detection, and treatment of CKM disease, we can achieve this critical goal. Semin Nephrol 36:x-xx © 20XX Elsevier Inc. All rights reserved.

Implications of Bias in Artificial Intelligence: Considerations for Cardiovascular Imaging

PURPOSE OF REVIEW

Bias in artificial intelligence (AI) models can result in unintended consequences. In cardiovascular imaging, biased AI models used in clinical practice can negatively affect patient outcomes. Biased AI models result from decisions made when training and evaluating a model. This paper is a comprehensive guide for AI development teams to understand assumptions in datasets and chosen metrics for outcome/ground truth, and how this translates to real-world performance for cardiovascular disease (CVD).

RECENT FINDINGS

CVDs are the number one cause of mortality worldwide; however, the prevalence, burden, and outcomes of CVD vary across gender and race. Several biomarkers are also shown to vary among different populations and ethnic/racial groups. Inequalities in clinical trial inclusion, clinical presentation, diagnosis, and treatment are preserved in health data that is ultimately used to train AI algorithms, leading to potential biases in model performance. Despite the notion that AI models themselves are biased, AI can also help to mitigate bias (e.g., bias auditing tools). In this review paper, we describe in detail implicit and explicit biases in the care of cardiovascular disease that may be present in existing datasets but are not obvious to model developers. We review disparities in CVD outcomes across different genders and race groups, differences in treatment of historically marginalized groups, and disparities in clinical trials for various cardiovascular diseases and outcomes. Thereafter, we summarize some CVD AI literature that shows bias in CVD AI as well as approaches that AI is being used to mitigate CVD bias.

Trends in the likelihood of receiving percutaneous coronary intervention in a low-volume hospital and disparities by sociodemographic communities

INTRODUCTION

Over the past two decades, percutaneous coronary intervention (PCI) capacity has increased while coronary artery disease has decreased, potentially lowering per-hospital PCI volumes, which is associated with less favorable patient outcomes. Trends in the likelihood of receiving PCI in a low-volume center have not been well-documented, and it is unknown whether certain socioeconomic factors are associated with a greater risk of PCI in a low-volume facility. Our study aims to determine the likelihood of being treated in a low-volume PCI center over time and if this likelihood differs by sociodemographic factors.

METHODS

We conducted a retrospective cohort study of 374,066 hospitalized patients in California receiving PCI from January 1, 2010, to December 31, 2018. Our primary outcome was the likelihood of PCI discharges at a low-volume hospital (<150 PCI/year), and secondary outcomes included whether this likelihood varied across different sociodemographic groups and across low-volume hospitals stratified by high or low ZIP code median income.

RESULTS

The proportion of PCI discharges from low-volume hospitals increased from 5.4% to 11.0% over the study period. Patients of all sociodemographic groups considered were more likely to visit low-volume hospitals over time (P<0.001). Latinx patients were more likely to receive PCI at a low-volume hospital compared with non-Latinx White in 2010 with a 166% higher gap in 2018 (unadjusted proportions). The gaps in relative risk (RR) between Black, Latinx and Asian patients versus non-Latinx white increased over time, whereas the gap between private versus public/no insurance, and high versus low income decreased (interaction P<0.001). In low-income ZIP codes, patients with Medicaid were less likely to visit low-volume hospitals than patients with private insurance in 2010; however, this gap reversed and increased by 500% in 2018. Patients with low income were more likely to receive PCI at low-volume hospitals relative to patients with high income in all study years.

CONCLUSIONS

The likelihood of receiving PCI at low-volume hospitals has increased across all race/ethnicity, insurance, and income groups over time; however, this increase has not occurred evenly across all sociodemographic groups.

Race, Racism, and Cardiovascular Health: Applying a Social Determinants of Health Framework to Racial/Ethnic Disparities in Cardiovascular Disease

Health care in the United States has seen many great innovations and successes in the past decades. However, to this day, the color of a person's skin determines-to a considerable degree-his/her prospects of wellness; risk of disease, and death; and the quality of care received. Disparities in cardiovascular disease (CVD)-the leading cause of morbidity and mortality globally-are one of the starkest reminders of social injustices, and racial inequities, which continue to plague our society. People of color-including Black, Hispanic, American Indian, Asian, and others-experience varying degrees of social disadvantage that puts these groups at increased risk of CVD and poor disease outcomes, including mortality. Racial/ethnic disparities in CVD, while documented extensively, have not been examined from a broad, upstream, social determinants of health lens. In this review, we apply a comprehensive social determinants of health framework to better understand how structural racism increases individual and cumulative social determinants of health burden for historically underserved racial and ethnic groups, and increases their risk of CVD. We analyze the link between race, racism, and CVD, including major pathways and structural barriers to cardiovascular health, using 5 distinct social determinants of health domains: economic stability; neighborhood and physical environment; education; community and social context; and healthcare system. We conclude with a set of research and policy recommendations to inform future work in the field, and move a step closer to health equity.

Predictors of PCSK9 (Proprotein Convertase Subtilisin/Kexin Type 9) Inhibitor Prescriptions for Secondary Prevention of Clinical Atherosclerotic Cardiovascular Disease

BACKGROUND

Little is known about patterns of PCSK9i (proprotein convertase subtilisin/kexin type 9 inhibitor) use among patients with established clinical atherosclerotic cardiovascular disease. This study's objective was to describe PCSK9i prescribing patterns among patients with atherosclerotic cardiovascular disease.

METHODS

We used a national outpatient clinic registry linked to zip-code level on household income from the US Census to assess characteristics of patients with atherosclerotic cardiovascular disease and LDL-C (low-density lipoprotein cholesterol) <190 mg/dL between September 1, 2015, and September 30, 2019, who did and did not receive PCSK9i prescriptions and practice-level and temporal variation in PCSK9i prescriptions. We assessed predictors of PCSK9i prescription with a multivariable mixed effects regression model which included patient covariates as fixed effects and the cardiology practice as a random effect. Adjusted practice-level variation in PCSK9i prescribing was evaluated with median odds ratio (OR).

RESULTS

Of 2 148 100 patients meeting study inclusion criteria, 27 249 (1.3%) received PCSK9i prescriptions. Receiving a PCSK9i prescription was associated with White race (versus non-White: OR, 1.78 [95% CI, 1.55-1.83]); high estimated household income (versus low income: OR, 1.18 [95% CI, 1.08-1.29]), and urban or suburban (versus rural) practice location (urban: OR, 1.47 [95% CI, 1.32-1.64]; suburban: OR, 1.25 [95% CI, 1.13-1.39]). Hispanics had lower odds of receiving PCSK9i prescriptions (OR, 0.66 [95% CI, 0.57-0.76]). The adjusted median odds ratio was 2.68 (95% CI, 2.46-2.94), consistent with clinically significant practice-level variation in PCSK9i prescriptions. No differences in quarterly PCSK9i prescription rates were observed before and after price reductions for evolocumab and alirocumab initiated during the fourth quarter of 2018 and first quarter of 2019, respectively.

CONCLUSIONS

This study highlights racial, socioeconomic, geographic, and practice-level variations in early PCSK9i prescriptions which persist despite adjustment for clinical and demographic factors. After adjustment, 2 randomly selected practices would differ in likelihood of PCSK9i prescription by a factor of >2.

The association of Medicaid expansion and racial/ethnic inequities in access, treatment, and outcomes for patients with acute myocardial infarction

Introduction

After having an acute myocardial infarction (AMI), racial and ethnic minorities have less access to care, decreased rates of invasive treatments such as percutaneous coronary intervention (PCI), and worse outcomes compared with white patients. The objective of this study was to determine whether the Affordable Care Act’s expansion of Medicaid eligibility was associated with changes in racial disparities in access, treatments, and outcomes after AMI.

Methods

Quasi-experimental, difference-in-differences-in-differences analysis of non-Hispanic white and minority patients with acute myocardial infarction in California and Florida from 2010–2015, using linear regression models to estimate the difference-in-differences. This population-based sample included all Medicaid and uninsured patients ages 18–64 hospitalized with acute myocardial infarction in California, which expanded Medicaid through the Affordable Care Act beginning as early as July 2011 in certain counties, and Florida, which did not expand Medicaid. The main outcomes included rates of admission to hospitals capable of performing PCI, rates of transfer for patients who first presented to hospitals that did not perform PCI, rates of PCI during hospitalization and rates of early (within 48 hours of admission) PCI, rates of readmission to the hospital within 30 days, and rates of in-hospital mortality.

Results

A total of 55,991 hospital admissions met inclusion criteria, 32,540 of which were in California and 23,451 were in Florida. Among patients with AMI who initially presented to a non-PCI hospital, the likelihood of being transferred increased by 12 percentage points (95% CI 2 to 21) for minority patients relative to white patients after the Medicaid expansion. The likelihood of undergoing PCI increased by 3 percentage points (95% CI 0 to 5) for minority patients relative to white patients after the Medicaid expansion. We did not find an association between the Medicaid expansion and racial disparities in overall likelihood of admission to a PCI hospital, hospital readmissions, or in-hospital mortality.

Conclusions

The Medicaid expansion was associated with a decrease in racial disparities in transfers and rates of PCI after AMI. We did not find an association between the Medicaid expansion and admission to a PCI hospital, readmissions, and in-hospital mortality. Additional factors outside of insurance coverage likely continue to contribute to disparities in outcomes after AMI. These findings are crucial for policy makers seeking to reduce racial disparities in access, treatment and outcomes in AMI.

Comparison of Long-Term Clinical Outcomes After Drug-Eluting Stenting in Blacks-vs-Whites

Patients of different racial backgrounds may have socioeconomic, cultural, or genetic differences that impact outcomes after percutaneous coronary intervention (PCI). There are limited data beyond 2 to 3 years for Blacks to inform discussions and perhaps improve outcomes. We studied consecutive limus-stent treated patients, having their first PCI at our institution January 2003 to March 2010 in 2 cohorts; Cohort 1: standard 3-year follow-up (n = 3,782, 12.4% Blacks) and Cohort 2: from nearby zip codes with intended detailed follow-up through 8 to 13 years (n = 616, 31.8% Blacks). The primary outcomes of interest were mortality and death/MI/revascularization (DMIR) (Cohort 1) or major adverse cardiac events (cardiac DMIR) (Cohort 2). In all cohorts, Blacks had a higher prevalence of many risk factors. In Cohort 1, 3-year mortalities were 14.6% and 9.6% (p = 0.001) and DMIR were 32.1% and 25.0% (p = 0.001), for Blacks and Whites, respectively. In Cohort 2, over 9.5 ± 2.0 years, treatment intensity was as high or higher for Blacks, but they continued to have higher low-density lipoprotein-cholesterol and blood pressure values. Major adverse cardiac events and mortality at 10 years were higher for Blacks (59.0% vs 48.1%, p = 0.024 and 44.3% vs 23.0%, p < 0.001). Differences in outcomes, except 10 year mortality, were not significantly different after adjustment for baseline characteristics. Blacks have a higher risk profile at the time of PCI and worse long-term outcomes after drug-eluting stent, most of which is explained by baseline differences.

Racial differences in long-term outcomes among black and white patients with drug-eluting stents

BACKGROUND

Some studies suggest that black patients may have worse outcomes after drug-eluting stent (DES) placement. There are limited data characterizing long-term outcomes by race. The objective was to compare long-term outcomes between black and white patients after percutaneous coronary intervention (PCI) with DES implantation.

METHODS

We analyzed 915 black and 3,559 white (n = 4,474) consecutive patients who underwent DES placement at Duke University Medical Center from 2005 through 2013. Over 6-year follow up, we compared rates of myocardial infarction (MI), all-cause mortality, revascularization, and major bleeding between black and white patients. A multivariable Cox regression model was fit to adjust for potentially confounding variables. Dual-antiplatelet therapy use over time was determined by patient follow-up surveys and compared by race.

RESULTS

Black patients were younger; were more often female; had higher body mass indexes; had more diabetes mellitus, hypertension, and renal disease; and had lower median household incomes than white patients (P < .001). At 6 years after DES placement, black relative to white patients had higher unadjusted rates of MI (12.1% vs 10.1%, hazard ratio 1.25, 95% CI 1.00-1.57, P = .05) and major bleeding (17.8% vs 14.3%, hazard ratio 1.28, 95% CI 1.07-1.54, P = .01), but there were no significant differences in other outcomes. After multivariable adjustment, there were no statistically significant racial differences in any of these outcomes at 6 years. Similarly, dual-antiplatelet therapy use was comparable between racial groups.

CONCLUSIONS

Unadjusted rates of MI and major bleeding over long-term follow up were higher among black patients compared to white patients, but these differences may be explained by racial differences in comorbid disease.

Outcomes by Gender and Ethnicity After Percutaneous Coronary Intervention

Limited data on gender differences by ethnicity after percutaneous coronary intervention (PCI) exist. In this prospective cohort study, we examined gender differences in 1-year outcomes among patients from 4 ethnic groups who underwent PCI from 2010 to 2016 at a tertiary center. The primary outcome was 1-year major adverse cardiovascular events (MACE) defined as composite of all-cause death, nonfatal myocardial infarction (MI), or target lesion revascularization. Secondary outcomes included composite of death or MI and individual components of MACE. Baseline characteristics and outcomes were compared between gender in each ethnic group. The study included 16,361 patients: 7,881 whites (26.1% women), 1,943 blacks (47.3% women), 2,621 Asians (22.6% women), and 3,916 Hispanics (39.3% women). Women were older with more co-morbidities than men. Unadjusted, women had higher incidence of 1-year MACE than men among whites and Asians but not blacks or Hispanics, which was driven by a greater incidence of death in white women and greater incidence of MI in Asian women compared with male counterparts. After adjustment, findings showed similar risk of 1-year MACE in women versus men in whites, Asians, and Hispanics (Whites: hazard ratio [HR] 0.95, 95% confidence interval [CI] 0.78 to 1.16; Asians: HR 1.14, 95% CI 0.77 to 1.67; Hispanics: HR 0.97, 95% CI 0.74 to 1.27). Black women had lower risk of 1-year MACE compared with black men (HR 0.67, 95% CI 0.46 to 0.97), driven by lower risk of death or MI. In conclusion, this study suggests that risk factors account for adverse events in women after PCI.

Comparison of the Cost of Drug-Eluting Stents versus Bare Metal Stents in the Treatment of Critical Limb Ischemia in the United States

BACKGROUND

Despite significant technical advancement in the last decade, the durability of endovascular management of critical limb ischemia (CLI) remains highly debatable. Drug-eluting stents (DESs) are being popularized for the management of CLI after its precedent success in coronary intervention. Initial reports on the durability of DES are promising. However, little is known on the additional cost of this relatively newer technology. The aim of this study is to compare the cost of the traditional bare metal stents (BMSs) to the newly introduced DES in a large cohort of CLI patients.

METHODS

Using the Premier database (2009-2015), we identified all patients with CLI undergoing DES and BMS. A multivariable generalized linear model was implemented to examine in-hospital cost adjusting for patients' characteristics, comorbidities, and regional characteristics.

RESULTS

A total of 20,702 patients with CLI underwent peripheral artery revascularization using BMS (18,924 [91.41%]) or DES (1,778 [8.6%]). Majority of patients were males (53%) and whites (71%). Patients undergoing BMS were slightly younger (median age [interquartile range]: 70 [62-79] versus 71 [63-80]) and were more likely to be smokers (46% vs. 39%) and have a history of cerebrovascular disease (10% vs. 8%) and chronic pulmonary disease (24.5% vs. 20.9%) as compared with those undergoing DES (all P < 0.05). On the other hand, DES patients had a high prevalence of diabetes (4% vs. 3%) and renal disease (25% vs. 22%) (both P < 0.05). There was also a significant increase in the proportion of patients undergoing DES and a corresponding decrease in BMS (P < 0.001) over the study period. Median total in-hospitalization cost (BMS: $13,342 [8,574 to 21,166], DES: $13,243 [8,560-20,232], P = 0.76) was similar for both approaches. After adjusting for potential confounders, DES was associated with $407 higher cost than BMS (adjusted mean difference [95% confidence interval]: 407 [17 to 798], P = 0.04). In addition, the cost was $672 higher in teaching hospitals, $1,153 higher in Rural areas, and increased in all regions compared with the Midwest (adjusted mean difference [95% confidence interval]-South: $293 [31 to 555], Northeast: $2,006 [1,517 to 2,495], West: $3,312 [2,930 to 3,695], all P < 0.05).

CONCLUSIONS

In this large cohort of CLI patients, after controlling for potential confounders, we demonstrated that the cost of endovascular revascularization is significantly higher in patients undergoing DES than those undergoing BMS. Regional disparities in cost were also observed. Further studies looking at the long-term durability and costs of DES versus BMS are needed.

Racial Differences in Quality of Care and Outcomes After Acute Coronary Syndrome

Guideline adherence and variation in acute coronary syndrome (ACS) outcomes by race in the modern era of drug-eluting stents (DES) are not well understood. Previous studies also fail to capture rapidly growing minority populations, such as Asians. A retrospective analysis of 689,238 hospitalizations for ACS across all insurance types from 2008 to 2011 from the Healthcare Cost and Utilization Project database was performed to determine whether quality of ACS care and mortality differ by race (white, black, Asian, Hispanic, or Native American), with adjustment for patient clinical and demographic characteristics and clustering by hospital. We found that black patients had the lowest in-hospital mortality rates (5% vs 6% to 7% for other races, p <0.0001, odds ratio [OR] 1.02, 95% confidence interval [CI] 0.97 to 1.07), despite low rates of timely angiography in ST-elevation myocardial infarction and non-ST-elevation myocardial infarction, and lower use of DES (30% vs 38% to 40% for other races, p <0.0001). In contrast, Asian patients had the highest in-hospital mortality rates (7% vs 5% to 7% for other races, p <0.0001, odds ratio 1.13, 95% CI 1.08 to 1.20, relative to white patients), despite higher rates of timely angiography in ST-elevation myocardial infarction and non-ST-elevation myocardial infarction, and the highest use of DES (74% vs 63% to 68% for other races, p <0.0001). Asian patients had the worst in-hospital mortality outcomes after ACS, despite high use of early invasive treatments. Black patients had better in-hospital outcomes despite receiving less guideline-driven care.

Safety and efficacy of second-generation drug-eluting stents compared with bare-metal stents: An updated meta-analysis and regression of 9 randomized clinical trials

The efficacy of second-generation drug-eluting stents (DES; eg, everolimus and zotarolimus) compared with bare-metal stents (BMS) in patients undergoing percutaneous coronary intervention was challenged recently by new evidence from large clinical trials. Thus, we aimed to conduct an updated systematic review and meta-analysis of randomized clinical trials (RCTs) evaluating the efficacy and safety of second-generation DES compared with BMS. Electronic databases were systematically searched for all RCTs comparing second-generation DES with BMS and reporting clinical outcomes. The primary efficacy outcome was major adverse cardiac events (MACE); the primary safety outcome was definite stent thrombosis. The DerSimonian and Laird method was used for estimation of summary risk ratios (RR). A total of 9 trials involving 17 682 patients were included in the final analysis. Compared with BMS, second-generation DES were associated with decreased incidence of MACE (RR: 0.78, 95% confidence interval [CI]: 0.69-0.88), driven by the decreased incidence of myocardial infarction (MI) (RR: 0.67, 95% CI: 0.48-0.95), target-lesion revascularization (RR: 0.47, 95% CI: 0.42-0.53), definite stent thrombosis (RR: 0.57, 95% CI: 0.41-0.78), and definite/probable stent thrombosis (RR: 0.54, 95% CI: 0.38-0.80). The incidence of all-cause mortality was similar between groups (RR: 0.94, 95% CI: 0.79-1.10). Meta-regression showed lower incidences of MI with DES implantation in elderly and diabetic patients (P = 0.026 and P < 0.0001, respectively). Compared with BMS, second-generation DES appear to be associated with a lower incidence of MACE, mainly driven by lower rates of target-lesion revascularization, MI, and stent thrombosis. However, all-cause mortality appears similar between groups.