Cardiovascular disease is the leading cause of death in both white and black Americans [1]. Racial disparities in cardiovascular care have been documented in the medical literature for over two decades [2, 3]. Yet, in studies on physician awareness of this issue, physician awareness is reportedly low. A 2005 study reported the results of a survey of attending cardiologists questioned about racial disparities in cardiac care [4]. Only 33 % of the physicians believed that racial disparities exist in health care in general, with only 5 % reporting awareness of such disparities in their own practice. A more contemporary study focused on awareness of racial disparities among internal and emergency medicine residents rotating through a coronary care unit [5]. The residents completed a survey on quality and disparities in cardiovascular care before and after attending a 1 h seminar on racial disparities in the USA. Prior to the seminar, 35 % of residents believed that racial disparities existed on a national level, and 7 % believed they had personally cared for a patient who experienced a racial disparity in treatment. After the short educational seminar, 85 % of residents acknowledged racial disparities in the US health system, and 32 % agreed that disparities are present on an individual level. Given that nearly 200 publications between 1983 and 2003 documented racial and ethnic disparities in the treatment of acute myocardial infarction [6], the lack of awareness among fully trained heart specialists and trainees documented in these reports is staggering. At the time of preparation of this manuscript, our MEDLINE database search did not reveal more current references on physician awareness of racial disparities in heart care, indicating that this is an area in need of further investigation. Here, we will review racial disparities in the utilization of four therapeutic cardiovascular procedures: automatic implantable cardioverter-defibrillator (AICD) implantation in patients surviving or at risk for sudden cardiac death, cardiac resynchronization therapy with defibrillation (CRT-D) in heart failure patients, reperfusion therapy in patients suffering from acute myocardial infarction, and mechanical revascularization procedures in patients with critical lower extremity ischemia. We will discuss potential culprits of these disparities with a particular focus on hospital quality, physician bias, and the relative lack of diversity among cardiovascular physicians in the USA. Finally, we will discuss strategies already in progress that hold promise to reduce or eliminate racial disparities in cardiovascular care.
Automatic implantable cardioverter-defibrillators (AICD) have been shown to prolong life in cardiac arrest survivors [7], and after the publication of major trials that define this survival benefit, the annual number of implants increased dramatically [8]. Groeneveld [9] and colleagues found that although AICD implantation improved long-term survival in the group of cardiac arrest survivors that they examined, there were racial disparities in the use of this technology. Black patients were less likely to receive an implant than their white counterparts with an odds ratio (OR) of 0.58, a discrepancy that was associated with reduced long-term survival in the black patients. The fact that the study was conducted solely in Medicare recipients makes it less likely that this discrepancy was due to ability to pay. In another study examining cardiovascular care of about 50,000 veterans, it was determined that black patients at Veterans Affairs academic hospitals who were at risk for cardiac arrest were less likely than white veterans at similar medical centers to be treated with prophylactic AICD implantation (OR 0.54) [10]. Disparities in AICD implantation by race have also been demonstrated at hospitals participating in national quality improvement programs. Reviewing outcomes of patients treated at hospitals participating in the American Heart Association “Get With the Guidelines” program, Hernandez and colleagues [11] revealed that of approximately 13,000 heart failure patients with a severely diminished left ventricular ejection fraction of <30 %—prime candidates for sudden cardiac death and patients for whom AICD implantation is a Class I indication [12]—28.2 % of black women and 33.4 % of black men received an AICD, compared to 43.6 % of white men. After adjusting for patient characteristics, hospital factors, and study population, the odds ratio for AICD implantation in black women compared to white men was 0.54. A recent study by Thomas et al. [13] reviewed a possible link between racial differences in preference of AICD therapy by employing a video decision aid. The video was shown to patients who were candidates for AICD implantation, and included patient testimonials, animations, and a multidisciplinary team of nurses and physicians describing the procedure’s risks and benefits. Half of the patients in the study were randomized to receive counseling with the video approach, and half were randomized to a control group receiving health care provider counseling without a video. The video decision aid decreased the racial disparity in patient preference for an AICD. However, black patients in the control group were still less likely than white patients to prefer the procedure to medical therapy.
These studies suggest that black patients that have survived or who are at risk for sudden cardiac death are only about half as likely as their white counterparts to be treated with a device that has been demonstrated to prolong life. This disparity does not appear to be impacted by payer mix or veteran status. There is some suggestion that patient preference may play a role, and that this may be remediable through patient education efforts.
Cardiac resynchronization therapy with defibrillation (CRT-D) is another key therapy for patients with advanced heart failure that reduces hospitalizations and mortality in this population [14]. It is notable that even though CRT-D is a newer therapy in cardiovascular medicine, its application follows a similar trend as earlier therapies regarding its underutilization in particular racial groups. In order to study current trends in CRT-D use by race, Eapen and colleagues [14] evaluated 107,096 patients from the National Cardiovascular Data Registry receiving an AICD who were also eligible for CRT-D therapy. While there was a significant increase in CRT-D implantation over the 4-year study among whites, blacks, and Hispanics, the odds ratio for CRT-D implantation was 0.69 for black patients vs. white patients and 0.84 for Hispanic patients vs. white patients. This trend was also seen in a sub-analysis of Medicare patients between white and black patients, essentially negating ability to pay as a contributing factor. A similar study was conducted by Farmer et al [15] to identify potential racial disparities in CRT-D use in patients who receive an AICD, while also evaluating trends in out-of-guideline use of CRT-D among different races. Current criteria for CRT-D eligibility are QRS duration >120 msec, left ventricular ejection fraction <35 %, New York Heart Association Class 3 or 4 congestive heart failure (CHF), and optimal medical management for heart failure [16]. The study included 22,205 patients of white, black, and Hispanic ethnicity who had an ICD implanted and were also eligible for CRT-D. After adjusting for multiple confounding variables, results indicated that black and Hispanic patients were less likely to receive CRT-D than white patients with OR of 0.84 and 0.83, respectively. In conducting a guideline-based analysis on recipients of CRT-D, black and Hispanic patients were more likely to meet clinical guidelines than white patients at an adjusted odds ratio of 1.18 and 1.17, respectively. Thus, despite black and Hispanic patients meeting eligibility criteria more often, they were still less likely than white patients to received CRT-D therapy.
There are numerous reports documenting racial disparities in the treatment of acute and chronic coronary artery disease. Coronary reperfusion therapies such as thrombolytic therapy and percutaneous coronary intervention (PCI) have dramatically improved survival in acute myocardial infarction patients [17]. Despite this, a study by Manhapra et al [18] showed that black patients suffering from a myocardial infarction who were eligible for thrombolytic therapy were significantly less likely than whites to receive it. In a study of 10,469 black patients diagnosed with an ST segment elevation acute myocardial infarction (STEMI) and eligible for thrombolytic reperfusion therapy, 47 % of these patients did not receive any therapy. Fifty-five percent of these black patients were 70 years of age or older, and in this older group two-thirds were not treated with reperfusion therapy. In a report by Peterson and colleagues [19], the records of 33,641 male veterans hospitalized in a VA facility for acute myocardial infarction were analyzed to determine utilization rates of major coronary interventions. Overall, black veterans were less likely to receive major coronary procedures than white veterans within 90 days of an acute myocardial infarction. Black veterans were also 33 % less likely to have a diagnostic cardiac catheterization, 42 % less likely to undergo percutaneous coronary intervention, and 54 % less likely to have a coronary bypass surgery. Thus, with regards to coronary reperfusion in acute myocardial infarction, data suggest that blacks are less likely than whites to receive invasive and therapeutic procedures.
Racial disparities in treatment have also been demonstrated among chest pain patients deemed to be low to intermediate risk. Napoli et al. [20] conducted a retrospective observational study of 2,451 patients who presented to the emergency department with low to intermediate risk chest pain to determine if there were racial disparities in stress testing. Patients were also required to have non-dynamic electrocardiograms and non-elevated initial troponin I levels. Thrombolysis in Myocardial Infarction (TIMI) and Diamond & Forrester (D&F) scores were calculated for all participants. After controlling for patient insurance, black patients were much less likely to have stress testing than white patients, with odds ratios of 0.68 (TIMI) and 0.67 (D&F). In a separate statewide study in Michigan, Khambatta et al. [21] performed an analysis of all patients with coronary artery disease (CAD) undergoing percutaneous coronary intervention (PCI). A total of 65,175 patients across 44 different hospitals were included in the study with findings revealing that black patients were less likely than white patients to receive adjunctive therapy with prasugrel (10 % vs. 14.5 %), the adjunctive antiplatelet drug with the highest efficacy, and blacks were also less likely than whites to receive a drug-eluting stent (DES), the current gold standard of coronary stents in the absence of a contraindication. The lower rate of use of DES in black patients was still prevalent after adjusting for socioeconomic status and medical comorbidities. Upon further analysis, the authors concluded that the use of prasugrel and DES was lower in hospitals that treat a higher volume of black patients. The above data suggest that blacks are less likely than whites to receive the standard of care across the spectrum of CAD, from stable, low risk chest pain to life-threatening acute coronary syndromes such a STEMI. As in the case with racial disparities in AICD and CRT-D implantation, at least some reports dismiss payer or veteran’s status as a major explanation for these disparities in CAD care.
Critical lower extremity ischemia in patients with peripheral arterial disease (PAD) can reduce the quality of life and eventually lead to loss of limbs. Racial disparities in mechanical revascularization procedures in PAD patients have been widely documented. Guadagnoli and colleagues [22] studied a random sample of 19,236 Medicare patients with lower extremity ischemia, and it was discovered that black patients were two times as likely to undergo above-the-knee or below-the-knee amputation. White patients were nearly twice as likely as black patients to undergo limb-preserving mechanical revascularization procedures like balloon angioplasty, stent placement, or bypass surgery. A separate study by Eslami et al. [23] examined outcomes of 691,833 patients with lower extremity ischemia at an urban hospital. Two thirds of these patients had surgical or invasive procedures of some type and 33.7 % underwent limb amputation. Further analysis revealed that black patients and those with lower incomes were overrepresented in the amputation group. As a result, black patients were 1.9 times as likely to have an amputation compared with white patients, and patients in a low income group were 1.4 times as likely to have an amputation compared with high income patients. Thus, evidence suggests that among Medicare beneficiaries in urban hospitals, blacks with critical lower extremity ischemia are less likely than their white counterparts to receive therapeutic revascularization procedures and more likely to be treated with limb amputation. This disparity is not completely explained by the patient’s ability to pay or level of disease at presentation. Racial disparities in PAD treatment among white and black patients have also been documented outside of the USA: Ahmad and colleagues [24] in a study of 161,523 procedures in England showed that black patients had significantly higher rates of lower limb amputation than white patients (OR 1.45). This disparity was especially striking in the female population, where black women were 2.4 times more likely than white women to have lower limb amputations. Interestingly, the disparities persisted after adjustment for age, sex, and social class (considers income and employment). In a similar study, Hughes et al. [25] studied a population of 240,139 patients from the Nationwide Inpatient Sample (NIS) database who presented with critical limb ischemia. Black patients made up 20 % of the total patient sample, however represented 25 % of the total lower extremity amputations performed. Because of the potential confounding effect of prohibitive comorbidities, the study also included an analysis on the relative number of comorbidities between black and white patients. White patients were significantly more likely to have cardiac and pulmonary comorbidities than black patients. In a separate study on racial disparities in PAD care, Durazzo and colleagues [26] investigated access to care and an institution’s capacity to perform revascularization procedures as potential underlying explanations. Researchers analyzed 774,399 patients from the NIS Database showing that more black than white patients had an amputation to treat critical PAD at rates of 56.4 and 34.5 %, respectively. It was discovered that black race alone increased the odds of having an amputation (OR 1.78) independent of socioeconomic status or insurance. Astonishingly, the observed racial disparities in amputations between black and white patients occurred more often at institutions with the greatest resources for performing revascularization (OR 1.8). Researchers also addressed the degree of ischemia upon presentation to the hospital to explore the possibility that a more advanced disease presentation may preclude patients from a revascularization procedure. After accounting for this variable in the regression model, the racial disparities in PAD treatment were still observed. In summary, blacks receive disparate treatment of critical limb ischemia with the use of amputation as a treatment modality more often than whites both in the USA and abroad. At least one study suggests that severity of disease is not an explanation of the unequal treatment, as is often suggested.