Circ: Closing the gap of gender/racial disparities in ICD use
Previous studies have outlined gender and racial disparities within healthcare, including the low use of implantable cardioverter-defibrillators (ICD) as a primary prevention method in women and blacks. But a study published March 7 in Circulation showed that this gap may be narrowing after researchers found a significant increase in ICD therapy in all sex and racial groups. But while racial disparities were no longer present within ICD, sex differences still persisted.

“Several randomized clinical trials have established the survival benefit of the implantable cardioverter-defibrillator (ICD) in patients with systolic heart failure (HF),” wrote Sana M. Al-Khatib, MD, MHS, of the Duke Clinical Research Institute and Duke University School of Medicine in Durham, N.C., and colleagues. “Despite the evidence from randomized clinical trials and practice guidelines, ICDs are underused in many potentially eligible patients. This problem is further compounded by the well-described race- and sex-based disparities in the use of this therapy.”

For example, an analysis of a Medicare claims database previously showed that women were three times less likely to receive an ICD for primary prevention and nearly 2.5 times less likely to receive an ICD for secondary prevention when compared with men. Additionally, for ICD use among patients with HF included in the American Heart Association’s Get with the Guidelines-Heart Failure (GWTG-HF) program, only one-third of eligible patients had an ICD in place. The rate of ICD use in black men, white women and black women was 27 percent, 38 percent and 44 percent lower than that in white men, respectively.

To better understand these types of disparities, Al-Khatib and colleagues evaluated 11,880 patients with a history of HF and left ventricular ejection fractions of 35 percent or less who were 65 years old or older and enrolled in GWTG-HF between January 2005 and December 2009. The authors determined the rate of ICD use by year for the population and for various sex and race groups.

Of the patient cohort, 63.9 percent were male, 77.4 percent were white, 70.1 percent had hypertension and 69.8 percent had ischemic heart disease.

The researchers found that overall, between 2005 and 2007, ICD use increased from 30.2 percent to 42.4 percent, but remained unchanged from 2008 to 2009. Additionally, Al-Khatib et al found that ICD use increased from 13.5 percent to 36.8 percent in black women, 23.1 percent to 31.1 percent in white women, 24.5 percent to 47.2 percent in black men and 36.1 percent to 50.6 percent in white men.

After the authors adjusted for patient and hospital factors, they found a significant increase in ICD use over time from the beginning of the study until mid-2007. This increase was also seen across all sex and race groups.

However, compared with white men, both white and black women had a lower probability of having an ICD in both past and present time periods. Black men did not differ from white men in either time periods.

“[A]ll four race and sex groups had a significant increase in ICD uptake, ranging from 8 percent in white women to 23.3 percent in black women,” the authors wrote. Increased ICD use was greatest among blacks, and while the increase in ICD use between blacks vs. whites was not statistically significant, the previously reported racial disparities in ICD were no longer present. However, sex differences did continue, the authors found.

“Some of these reasons may explain the persistent low use of ICD therapy in our overall population and in women and racial minority groups,” Al-Khatib et al wrote. “Other factors that may account for lower use of ICDs in women are the relatively small number of women enrolled in randomized clinical trials of primary prevention ICD therapy and the published studies on the potential lack of benefit of ICD therapy in women.”

The authors said that currently, there are no performance measures outlining proper implantation of ICDs in eligible patients; however, a writing group has proposed ICD counseling in eligible patients as an HF performance measure.

The researchers said that if launched, “this performance measure, along with other future ICD-related performance measures, may help to improve adherence to guidelines and to reduce disparities. To that end, these performance measures should be reported by race, ethnicity, sex and age.”

While the authors found that ICD use increased between 2005 and 2009, they summed that sex differences in ICD use are still evident and offered that it will be important to understand the factors that contribute to these types of disparities.