despite guidelines that call for such an approach, according to findings from the first reported large-scale, multicenter study of PA testing practices.
Researchers ran a retrospective review of PA testing among 269,010 patients who met the definition as having treatment-resistant hypertension and were managed at any one of 130 Veterans Health Administration (VHA) medical centers from 2000 to 2017.
The results showed that, despite the fact that primary aldosteronism is highly prevalent among patients with treatment-resistant hypertension, only 4,277 (1.6%) underwent assessment for PA during a median of 3.3 years’ follow-up after they first met the defining criteria, Jordana B. Cohen, MD, and her associates reported in a study published in Annals of Internal Medicine on December 28.
“Testing rates also did not change meaningfully over nearly 2 decades ... despite an increasing number of guidelines recommending testing for primary aldosteronism in this population,” including the most recent recommendations from the Endocrine Society, issued in 2016, noted Dr. Cohen, a nephrologist and hypertension researcher at the University of Pennsylvania in Philadelphia, and colleagues.
Most patients in the study (almost 90%) were seen by a primary care practitioner (PCP).
The small percentage of patients seen by a nephrologist or endocrinologist were more than twice as likely to be tested for PA than those seen by a PCP or cardiologist.
Those clinicians who did order a test for PA were much more likely to treat patients with the appropriate medication, a mineralocorticoid receptor antagonist (MRA). In addition, therapy was started sooner, the researchers found.
“Our results corroborate” earlier reports from smaller health systems and suggest that dramatic underuse of PA assessment “is an issue across the US,” Dr. Cohen said in an interview.
The VHA experience “is very representative of what we think goes on across U.S. practice” and contrasts with the VHA’s reputation for “doing a pretty good job managing hypertension” in general, she noted.
Missed diagnosis, missed treatment
Dr. Cohen believes a number of factors likely help drive the abysmally low rate of PA testing they observed in the VHA system. She believes rates of PA testing are low elsewhere as well.
First, optimal hypertension management “is often taken for granted” but is challenging in busy primary care practices, so many of patients likely fall through the cracks, she said.
Dr. Cohen cited efforts at her institution, as well as by the VHA system, to better employ electronic health records to flag patients with treatment-resistant hypertension – defined as patients whose systolic or diastolic blood pressure remains at or above 140/90 mm Hg on at least two successive measurements at least a month apart while the patient is undergoing treatment with three conventional antihypertensive drugs – and to guide clinicians to order the right tests and treatments for these patients.
Many care providers mistakenly “see treatment-resistant hypertension as a disease of noncompliance,” although it is much more often the result of a missed diagnosis and inadequate intervention, she explained.