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Updated recommendations for the diagnosis and management of resistant hypertension (RH) have been released by the American Heart Association (AHA) that lower the threshold to 130/80 mm Hg.

The document is the first revision since the AHA's initial 2008 scientific statement on hypertension, noted Robert M. Carey, MD, of the University of Virginia Health Sciences Center in Charlottesville, and colleagues.

The statement reflects the 2017 American College of Cardiology/AHA hypertension , which reduced BP thresholds for initiation of antihypertensive therapy in higher-risk adults to >130/80 mm Hg, and BP treatment goals to <130/80 mm Hg for most individuals.

Writing in , the authors noted that RH, which affects an estimated 12% to 15% of individuals treated for high blood pressure (BP), is defined as BP that remains elevated above the target of 130/80 mm Hg despite concurrent treatment with three antihypertensive agents of different classes, at maximum or maximally tolerated doses and at the appropriate dosing frequency. It also includes patients requiring four or more antihypertensives to achieve blood pressure targets.

Other major changes include use of more specific diagnostic criteria for resistant hypertension, acknowledgement of the importance of sleep duration and quality in BP control, and increased emphasis on early lifestyle measures regarding diet and physical activity to prevent and treat resistant hypertension.

African-Americans, men, older adults, and people who are obese are most commonly affected, and people with diabetes, peripheral artery disease, and obstructive sleep apnea are also at greater risk.

"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," said Carey, chair of the statement writing group, in a news release. "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."

The recommendations describe detection and management of a variety of factors that can mimic treatment-resistant hypertension, which should be excluded prior to diagnosis of RH. These include poor treatment adherence (reported in 50% to 80% of patients treated for high BP); white-coat effect (shown to cardiovascular risk); treatment inertia on the part of clinicians; as well as unwanted BP effects of a variety of over-the-counter and prescribed medications, lifestyle factors such as smoking and excessive alcohol use, and in some salt-sensitive people, consumption of salt (which should be limited to less than 2,400 mg/daily, the guidelines state).

Patients should also be screened for secondary hypertension, which may be related to primary aldosteronism (in about 20% of people with RH), or to chronic kidney disease or renal artery stenosis.

"Once all identifiable forms of hypertension, particularly endocrine causes, have been excluded and contributions from the white-coat effect (office BP of at least 20/10 mm Hg higher than home or [ambulatory BP monitoring] measurements) and masked uncontrolled hypertension (office BP measurements suggesting adequate BP control but out-of-office readings elevated above goal) are considered, therapeutic approaches for improved BP control in resistant hypertension can begin," the AHA team wrote.

In addition to the RH patient's regimen of three mechanistically-complementary antihypertensive agents, -- usually a long-acting calcium channel blocker, an ACE inhibitor or angiotensin receptor blocker, and a diuretic -- treatment should be personalized and providers should consider switching from hydrochlorothiazide to chlorthalidone or indapamide, followed by the addition of mineralocorticoid receptor antagonist (spironolactone or eplerenone). If BP remains elevated, the recommendation is for stepwise addition of antihypertensive drugs with complementary mechanisms of action to lower BP; if BP remains uncontrolled, referral to a hypertension specialist is advised.

"In addition to poor adherence to treatment ... inadequate doses of the medications are often prescribed -- perhaps out of fear of side effects," American Society of Hypertension president John Bisognano, MD, commented to 麻豆传媒.

Given the substantial increase in preventable kidney and heart disease, "it is well worth devoting extra time and care to managing the side effects in these patients, as they have the most to gain of any hypertensive subpopulation from adequate and aggressive treatment with streamlined regimens using combination pills and affordable medications whenever possible."

In addition, he said, "longer-acting thiazide diuretics such as chlorthalidone and indapamide should be viewed as mainstay therapy [as they] provide an important treatment base with which other medications can act synergistically."

"While spironolactone, shown to be tremendously effective in patients with resistant hypertension, may cause hyperkalemia in a very small number of patients, it can often be balanced by appropriate use of other diuretics, and the laboratory monitoring is a relatively small price to pay for a blood pressure drop that can even reduce a patient's cardiovascular risk by 50%. The medication is dirt cheap, but for patients who cannot tolerate it, a newer aldosterone antagonist, eplerenone, can provide a similar benefit."

Carey and co-authors noted that the current approach to BP control in RH has focused on the addition or substitution of drugs or drug classes based on meaningful pharmacological principles that are only partially successful in "true resistant" hypertension. "Future research should seek to improve personalized antihypertensive drug selection in patients with RH."

The AHA writing group also emphasized the need to develop approaches involving pharmacogenetics and pharmacogenomics and expand the classes of pharmacological agents.

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