Half of All Patients With Hypertension Should be Screened for Primary Aldosteronism

A large population-based Canadian study finds that few patients are evaluated for primary aldosteronism, which is one of the most common causes of secondary hypertension.

Secondary hypertension remains largely unrecognized and untreated, write the authors of a study published online March 31 in JAMA Surgery. The study, which was led by Alexander A. Leung, MD, MPH, of the University of Calgary, found that half of patients with hypertension should be evaluated for primary aldosteronism, but they estimate that no more than 10% of these patients are screened and fewer than 1-2% of patients with hypertension are ever diagnosed or treated.

“These findings suggest that a system-level approach to assist with investigation and treatment of primary aldosteronism may be highly effective in closing care gaps and improving clinical outcomes,” the authors wrote.

In this study, researchers traced the path of care for primary aldosteronism finding that while this condition is known to be associated with leading to hypertension, few people are screened for the condition. The variations in screening were found to be vast and based on patient characteristics, but also geographic zones, the clinician’s specialty and system-level influences on patient screening. Of 1.1 million adults with hypertension, only 7,941 patients (0.7%) were screened for primary aldosteronism. Of those who were screened, 1,703 (21.4%) tested positive for the condition. And, 731 patients (42.9%) who tested positive at screening received treatment.

“Although approximately half of patients with hypertension should be screened for primary aldosteronism as a potential cause of high blood pressure, global screening rates are in fact much lower,” the authors wrote citing studies that show 7-8% of patients in Italy and Germany are treated for hypertension after having been screened for primary aldosteronism. Other studies have shown that screening rates are even lower for patients with resistant hypertension and hypokalemia—despite a high prevalence of primary aldosteronism in patients with these two conditions. Here in the US, one study showed that only 2% of this patient population was screened.

The authors noted some limitations in this study, which included the consideration of elevated aldosterone-to-renin ratio as sufficient for a primary aldosteronism diagnosis. There may have been some potential inaccuracies in screening tests due to different medicines patients were prescribed. “Although medication factors may result in some differences between individual aldosterone-to-renin ratio measurements, these are less likely to cause significant bias in our population estimates. Moreover, aldosterone-to-renin ratio measured without medication adjustment are increasingly accepted and used in clinical care, because discontinuation of medications is not always safe or possible,” the authors wrote.

Reference

Yuan-yuan Liu, MD, PhD; James King, MSc; Gregory A. Kline, MD; et al. “Outcomes of a Specialized Clinic on Rates of Investigation and Treatment of Primary Aldosteronism,” JAMA Surgery. Published online March 31, 2021. doi:10.1001/jamasurg.2021.0254