Resistant Hypertension: A Conversation with George Thomas, MD

When is hypertension considered resistant?

When at least three blood pressure medications from different classes, including a diuretic, given at maximal doses fail to control blood pressure to the patient’s goal. True resistance should be differentiated from false or “pseudo” resistance because so many factors can affect blood pressure.

What are some risk factors for resistant hypertension?

Older age and black race are nonmodifiable risk factors associated with resistant hypertension. Being overweight, excessive sodium consumption (> 1 teaspoon per day), and alcohol intake (> 2 drinks per day for men and > 1 drink per day for women) are modifiable risk factors. Secondary hypertension, which usually is treatable, can be caused by kidney disease, hormonal influences (such as pheochromocytoma or primary aldosteronism) and vascular disease (such as renal artery stenosis).

Causes of pseudoresistance include medications that can elevate blood pressure (such as NSAIDs and oral contraceptives), inappropriate blood pressure medication combinations or dosages, and incorrect blood pressure measurement at home or in the office.

How do you ensure accurate blood pressure readings?

We make sure the patient has not had caffeine, smoked or exercised for at least 30 minutes and is seated for at least five minutes in a quiet room with no distractions. We do readings with the cuff over the bare arm. The patient sits with the back supported, legs uncrossed and on the floor, and the arm supported at heart level.

Because of the potential for white-coat hypertension, we also have patients check their blood pressure at home or use a 24-hour ambulatory blood pressure monitor.

At-home measurements can be done with any validated device, preferably using an arm cuff. One of the recommended schedules is as follows: For one week prior to your clinic visit, check blood pressure in the morning (before medications) and in the evening (before going to bed). Take at least two blood pressure readings with each measurement. Bring the blood pressure machine and/or your logbook to your visit.

For the general population, an office reading of > 140/90 mm Hg on more than two visits, or an average home reading of > 135/85 mm Hg, is diagnostic of hypertension.

Are blood pressure goals different for some patients?

Using the 2014 evidence-based guidelines (JNC 8), the recommended goal blood pressure is < 140/90 mm Hg for adults age < 60 and for adults age ≥ 18 with chronic kidney disease or diabetes; the recommended goal is < 150/90 mm Hg for adults age ≥ 60.

Consider referral to a hypertension specialist when patients are not at goal despite multiple blood pressure medications, when you suspect secondary causes of hypertension or for consultation in managing complicated cases.

What resources does Cleveland Clinic offer for treating resistant hypertension?

Cleveland Clinic’s Department of Nephrology and Hypertension includes physicians who are certified as hypertension specialists by the American Society of Hypertension. Available cutting-edge diagnostic techniques include 24-hour ambulatory blood pressure monitoring, assessment of central pressures and hemodynamic testing to assess the cause of severe hypertension.