Even subclinical levels of primary aldosteronism can have an important impact on cardiovascular (CV) disease and could offer a potential target for risk reduction, according to a new study.

The link between primary aldosteronism and high blood pressure is well known. But Jenifer Brown, MD, cardiologist at Brigham and Women’s Hospital in Boston, said doctors have come to recognize that primary aldosteronism, a relatively rare condition in which the adrenal glands produce too much aldosterone, is more prevalent than previously thought. And the conditions exist over a spectrum where milder cases seem to be associated with changes in cardiac structure and other risk factors.

“There was still a gap in the evidence about whether this milder spectrum was associated with hard clinical outcomes,” she said.

Link Between Aldosterone-Renin Ratio (ARR) and CV Risk

Brown and her colleagues used data from the ARIC study to follow more than 3400 older adults with a mean age of 74.8 years for 9 years. All participants were free from CV disease at baseline.

The researchers compared participants’ ARR to incidents of CV events, including hospitalization for heart failure, atrial fibrillation, ischemic stroke, myocardial infarction, and a composite of these events plus all-cause death.

The work was published in JAMA Cardiology.

In the study group, ARR values ranged from 2.2 to 12.3 ng/dL per ng/mL/h, with a median of 5.1 ng/dL. Those with higher ratios were at a greater risk for the composite endpoint, atrial fibrillation, and stroke — though not myocardial infarction or hospitalization for heart failure — indicating that subclinical primary aldosteronism can still have important effects on CV health.

“This milder spectrum of primary aldosteronism is relevant to clinical risk,” Brown said.

‘A Modifiable Target’

John Giacona, PhD, PA-C, of UT Southwestern Medical Center in Dallas and director of Applied Clinical Research for the Primary Aldosteronism Foundation, said the study highlights the importance of screening for high aldosterone levels, particularly among older patients.

“Screening for primary aldosteronism is very low — we’re only screening about 2% of those at high risk,” he said. This low rate of screening persists despite the fact that primary aldosteronism is present in around 5%-10% of all hypertension patients, a number that rises to 25% among those with treatment-resistant hypertension.

Expanding screening, as recommended in 2025 guidelines from both the Endocrine Society and the American College of Cardiology/American Heart Association, is the first step to incorporating treatment for primary aldosteronism into a patient’s CV care.

“Aldosterone dysregulation is starting to appear to be a modifiable target for cardiovascular prevention,” he said. “Once you understand where a patient is at, you can start to make clinical decisions.”

Brown reported receiving consulting income from AstraZeneca. Giacona reported having no relevant financial relationships.

Brian Owens is a freelance journalist based in New Brunswick, Canada.