AHA tightens criteria for diagnosis of resistant hypertension

The American Heart Association has tightened its guidelines for diagnosing resistant hypertension—a condition that affects up to 15 percent of patients treated for high blood pressure—according to a scientific statement published this month.

The statement is the AHA’s first update on the topic in a decade and was spearheaded by Robert M. Carey, MD, chair of the writing committee and a professor of medicine at the University of Virginia Health Sciences Center.

“Because several conditions can mimic resistant hypertension, a correct diagnosis is essential so as not to over-medicate,” he said in a release.

The new statement tightens the definition of the condition, recognizing resistant hypertension in patients whose high blood pressure persists even when they’re taking three or more medications to control their BP. It also includes patients whose blood pressure achieves certain values on four or more different types of BP-lowering medications.

The statement comes nearly a year after the AHA and American College of Cardiology redefined hypertension as a systolic value of 130 over a diastolic value of 80. A host of factors could contribute to elevated BP, Carey and his team wrote, including over-the-counter NSAIDS like ibuprofen and prescription drugs like birth control pills. The authors also said between 50 and 80 percent of hypertensive patients don’t take their blood pressure medication consistently due to financial barriers, which can result in poor BP control.

The “white coat effect,” or the idea that blood pressure rises in the doctor’s office due to anxiety, could contribute, too, Carey and co-authors wrote—something they said could be remedied by using an at-home portable monitor and periodically tracking BP values over the course of the day.

When physicians can confirm a diagnosis of resistant hypertension, the statement recommends they start by working with their patients on some lifestyle changes, like decreased alcohol intake or tobacco use. Eating a DASH-style diet rich in produce and whole grains can also help.

“Some people with resistant hypertension may be extremely sensitive to salt in their diet,” Carey said. “In one of the studies we reviewed, when salt intake was significantly lowered in people with resistant hypertension, blood pressure promptly went down.”

Medication regimens will likely also change after a diagnosis of resistant hypertension, he said. The statement recommends physicians tweak the patient’s already existing routine of antihypertensive drugs, which typically include a long-acting calcium channel blocker, an angiotensin converting enzyme inhibitor and an angiotensin receptor blocker, for better BP control. If hypertension persists, the authors recommend prescribing a mineralocorticoid receptor antagonist, which can inhibit aldosterone to lower blood pressure.

“Patients with high blood pressure are more likely to develop cardiovascular diseases such as heart attacks, heart failure and stroke, and their prognosis deteriorates further if they have resistant hypertension,” Carey said. “It is extremely important to get blood pressure down by whatever means one can, because study after study has shown the negative outcomes from pressures that remain elevated above the target level.”