Quality of Anticoagulation Therapy Lower in Black Patients With A-fib

African-American patients with A-fib are less likely to receive direct oral anticoagulants (DOACs) and tend to have poorer control on warfarin compared with their white counterparts, a registry study shows, bolstering a literature already rife with evidence of racial disparities in cardiovascular medicine.

“What I was struck by were the significant differences even after controlling for socioeconomic status factors,” like education level, insurance type, and zip code-based income, lead author Utibe Essien, MD (University of Pittsburgh School of Medicine, PA), told TCTMD. “That was notable for me given that that typically has been the explanation for why racial differences exist.”

What is actually to blame for the observed disparities is unclear, but it could involve factors—many of which could not be assessed using this registry—at the patient, physician, and system levels, he said.

“On the patient side, I think we need to go back into the patient-physician relationship and see what those conversations in the office around treatment look like when a patient is newly diagnosed with atrial fibrillation,” Essien said. “Are patients trusting these newer medications that are on the market? Are they even made aware of the options that they have? And I think that’s certainly on the provider side. When they do hear about these newer medications, how much do they consider the cost of these meds in the calculus of whether they want to be on a newer agent compared to warfarin or compared to nothing?”

Biases on the part of physicians around whether patients will remain adherent or understand certain medications also could be contributing, Essien said.

“Those are some of the key features that we wish we could have measured that could potentially explain some of the differences, but we just unfortunately weren’t able to with these data,” he said.

All of us as physicians and all our patients engage the healthcare experience with biases that emanate from deep and firmly embedded life experiences. Clyde Yancy

Commenting for TCTMD, Jared Magnani, MD (University of Pittsburgh School of Medicine), who was not involved in the study, said it was an important contribution to the evidence base.

“We know that people of black race have a far poorer experience of atrial fibrillation in terms of treatment and outcomes than those of other races, and this registry further demonstrates that there are racial disparities that are persistent in how we address a common cardiovascular disease,” Magnani said.

“We need to have a concerted effort across multiple fronts to address a problem like this,” he argued, “because it’s about addressing health literacy, increasing access to care, improving the delivery of care, and [recognizing] that there are whole populations that experience increased vulnerability because they are underserved.”

Overall Anticoagulation Use Similar, but . . .

The study, published online November 28, 2018, ahead of print in JAMA Cardiology, builds on prior research showing that patients from minority populations—including African-Americans and Hispanics—have a lower prevalence of A-fib but are more likely to have poor outcomes after diagnosis compared with white patients. Previous studies also have shown that African-American and Hispanic patients are less likely to use oral anticoagulation, although there is little information on potential differences in DOAC use.

For this study, Essien et al examined data from the ORBIT-AF II registry, which enrolled outpatients with nontransient A-fib at 244 sites in the United States and followed them from February 2013 to July 2016. The current analysis included 12,417 patients: 89.4% white, 5.4% Hispanic, and 5.2% African-American.

Use of oral anticoagulation was high overall—88.9%, 87.3%, and 84.2% for white, African-American, and Hispanic patients, respectively—and there were no differences based on race or ethnicity in the proportion of patients with recorded contraindications.

African-American patients were less likely than white patients to receive oral anticoagulants after accounting for differences in clinical features, but further adjustment for socioeconomic factors rendered the difference nonsignificant.

Among treated patients, however, the lower likelihood of receiving a DOAC in African-Americans persisted after adjustment for socioeconomic factors (adjusted OR 0.73; 95% CI 0.55-0.95).

Overall anticoagulant use and the likelihood of being treated with a DOAC did not differ between the white and Hispanic groups.

The researchers also looked into potential differences in warfarin control by race or ethnicity. The median time in therapeutic range (TTR) was lower in both African-Americans (57.1%) and Hispanics (51.7%) than in white individuals (67.1%; P < 0.001). Poor TTR has been associated with an elevated stroke risk, the authors note.

Moreover, among DOAC-treated patients, African-Americans and Hispanics were more likely than whites to receive inappropriate dosing.

What Should Be Done?

Magnani indicated that the explanation for the observed differences is not clear, noting that “individuals of black race have critical healthcare disparities that result from multiple social factors and multiple social determinants of health.” Bias in how physicians allocate care, he said, is likely only part of the story.

Healthcare providers can help address this issue, he suggested: “We as practitioners need to identify and address our unconscious biases. We also need a healthcare system that provides accessible healthcare for everyone in our country, in particular our most vulnerable populations. That doesn’t exist in our country. We’ve seen the assault on the safety net to provide care for people who are more impoverished, and people who are racial/ethnic minorities certainly are much more likely to experience poverty. And I think we also need to utilize tools such as the electronic health record to recognize gaps in care and to seek to remedy those on a systematic level.”

We . . . need a healthcare system that provides accessible healthcare for everyone in our country, in particular our most vulnerable populations. That doesn’t exist in our country. Jared Magnani

Registry data like these, Magnani added, can identify gaps in care and serve as an invitation to address them.

For Essien, the solution might involve a greater emphasis on shared decision-making around use of DOACs, efforts to improve use of the newer agents among nonspecialists, and addressing barriers related to cost, which is higher for the DOACs than for warfarin.

“I think that is certainly a big issue when providers and patients are taking a look at using these medications,” Essien said.

In an accompanying editor’s note, Clyde Yancy, MD (Northwestern University Feinberg School of Medicine, Chicago, IL), says, “We must be relentless in our focus to further narrow and ultimately eliminate disease disparities as a function of race/ethnicity.”

He highlights the potential influence of subconscious bias as an explanation for these differences.

“All of us as physicians and all our patients engage the healthcare experience with biases that emanate from deep and firmly embedded life experiences,” Yancy writes. “The goal is not to rewire culture but to change context. As evidence-based, quality-driven physicians, achieving the best care for all our patients is the only acceptable goal.

“We must continue to report performance as a function of race/ethnicity and seek actionable interventions,” he continues. “Falling short exposes our patients to untoward outcomes; in the case of those patients participating in the ORBIT-AF II trial, this is an unprotected vulnerability to stroke. This gap in cardiovascular care must be further addressed and eliminated.”