AHA 2017: Blacks less likely than whites to be prescribed oral anticoagulants

November 14, 2017 – Among patients hospitalized with atrial fibrillation (AF) black and white individuals vary in demographics, prevalence of non-cardiovascular comorbidities, and prescription of oral anticoagulation, say researchers.

A recent study presented by DCRI researchers at the annual American Heart Association conference in Anaheim, California, aimed to assess patient characteristics and oral anticoagulation (OAC) use at discharge by race in hospitalized atrial fibrillation (AF) patients.

“We have been very interested in understanding how AF effects different racial and ethnic populations and how management of AF may differ as a function of race and ethnicity,” said the DCRI’s Kevin Thomas, MD, first author of the study. “We already know black populations have a significantly lower burden of AF relative to whites despite having a higher burden of traditional risk factors for developing AF including, hypertension, diabetes, heart failure, and kidney dysfunction,”

Thomas called the provocative phenomenon the “AF paradox,” because the group that has more risk factors for developing AF actually has half as likely the chance of being diagnosed with it.

“Even though blacks are less likely to have AF, when they have it, some data suggests they have worse outcomes relative to whites,” said Thomas. “They have more strokes, higher mortality, and are more likely to develop heart failure. So, despite the prevalence being less, the outcomes are worse.”

According to the National Institutes of Health, AF, the most common clinically significant cardiac arrhythmia, affects over 2.3 million people in the United States. AF is associated with an increased risk of stroke and heart failure and independently increases the risk of all-cause mortality.

The researchers used data from 1 in 5 U.S. hospital discharges through the Premier Healthcare Database, a comprehensive electronic healthcare database with more than 700 contributing hospitals/healthcare systems. Data from 1,579,456 patients in 812 hospitals admitted between January 2011 and June 2015 with a primary or secondary AF diagnosis were used.

According to Thomas, the genesis of this study was to evaluate the characteristics of patients hospitalized for AF and how many of those eligible were being treated with OACs. The researchers wanted to understand how patients were treated and whether treatment differences explained why there may be overall higher rates of stroke associated with one population vs another.

The researchers found that blacks with AF were younger than whites and though the prevalence of cardiovascular comorbidities were similar, non-cardiovascular morbidities such as renal disease, pulmonary disease and history of DVT/PE were higher in blacks. Black patients of various age groups, despite having more risk factors, were also less likely to be treated and discharged on OACs as compared to white patients.

“The next phase of the analysis will be to take a deeper dive into understanding what might be driving these differences in OAC prescriptions,” said Thomas, “however the bad news for all individuals with AF is that we found that among eligible patients, only about 45 to 46 percent are prescribed OACs independent of race and ethnicity, which means more than half of eligible patients are not being prescribed blood thinners which could reduce strokes and also be life-saving.”

In addition to Thomas, other researchers included Roberta A. James, Victoria Marcsisin, Shah R. Bimal, Gregory J. Fermann, Susan M. Mashni, Michael B. Streiff, Elaine M. Hylek and Christopher B. Granger.