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New data challenge primary care’s inattention to aldosterone in hypertension


 

Jun Yang, MBBS, had watched as her father, who had battled hypertension for decades, ended up on four medications that still couldn’t bring his blood pressure to a healthy level. The cardiovascular endocrinologist then ran some tests, and soon thereafter her father had his blood pressure optimized on just one targeted medication.

Dr. Jun Yang, cardiovascular endocrinologist at the Hudson Institute of Medical Research and a hypertension researcher at Monash University, both in Melbourne. Courtesy Dr. Jun Yang

Dr. Jun Yang (right) and her father are shown.

Dr. Yang’s father was found to have a hormonal condition known as primary aldosteronism (PA) as the cause of his hypertension.

It turns out that PA is not as rare as once thought.

An eye-catching report in Annals of Internal Medicine this spring of an unexpectedly high prevalence of primary aldosteronism among a diverse cross section of U.S. patients with hypertension has raised issues that could dramatically change the way doctors in America, and elsewhere, assess and manage high blood pressure.

Foremost is the question of whether primary care physicians – the clinicians at the front line for diagnosing and initially treating most patients with hypertension – will absorb and act on this new evidence. For them, aldosteronism doesn’t automatically come to mind when they see high numbers on a BP monitor, and yet this latest research found that up to a third of all 726 patients in the study who were diagnosed with hypertension and with high urinary salt levels had PA.

That translates to a roughly three- to fivefold increase over standard prevalence estimates, and is a ”game changer” for how clinicians should approach hypertension management and PA diagnosis going forward, said John W. Funder, MD, in an editorial accompanying the Annals study.

Long considered relatively uncommon, hypertension driven by an excess of the hormone aldosterone, often because of an adenoma on the adrenal gland, is not the same as conventional “essential” hypertension. The former benefits from early diagnosis because its treatment is completely different – close to half of all PA patients can be treated definitively and quickly with surgical removal of an adenoma from one side of the adrenal gland.

For other PA patients, who have bilateral adrenal hyperplasia that is impossible to resolve surgically, treatment with drugs called mineralocorticoid receptor antagonists (MRAs), such as spironolactone, is needed because they target the hormonal cause of the high BP.

But what usually happens is that a patient with PA is mistakenly diagnosed with essential hypertension, in which the classic approach to treatment is to start with one regular antihypertensive drug, and add on further ones from different drug classes if blood pressure is not adequately controlled. When patients are taking three drugs, without adequate control, they are labeled as having “resistant hypertension.”

But in the case of PA, none of these conventional antihypertensives work, and the process of continuing to monitor and add different drugs wastes time, during which patients deteriorate.

“We need to change the culture of waiting for hypertension to be resistant and have patients riddled with end-organ damage,” due to years of persistently high BP and excess aldosterone “before we look for a secondary cause” like PA, declared Dr. Yang, of Hudson Institute of Medical Research and Monash University in Melbourne, during an interview.

So early diagnosis and prompt treatment of PA is key.

In addition to boosting the public health importance of early PA detection in hypertensive patients, the new up-sized PA prevalence numbers throw a spotlight on primary care physicians (PCPs) as key players who will need to apply the findings to practice on a public health scale.

These novel results create a need for “new guidelines, and a radically revised game plan with the key role of PCPs” emphasized in future management of patients with hypertension, said Dr. Funder, a professor of medicine at Monash University, in a second recent editorial in Hypertension.

Dr. Robert Carey, professor of medicine and dean emeritus at the University of Virginia, Charlottesville

Dr. Robert Carey

“Buy-in by PCPs is essential,” agrees Robert M. Carey, MD, a cardiovascular endocrinologist and professor of medicine at the University of Virginia in Charlottesville, and a coauthor of the new study.

But he too acknowledges that this presents a major challenge. PCPs and internists, who diagnose a lot of hypertension, are “not used to thinking about aldosterone,” he said in an interview, encapsulating the key problem faced by proponents of earlier and more widespread PA assessment.

This dilemma looms as a “huge public health issue,” Dr. Carey warned.

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