Managing Resistant Hypertension in the Primary Care Clinic
Resistant hypertension is common in the United States and around the world. According to 2013-2014 data from the National Health and Nutrition Examination Survey, about 50% of people surveyed had uncontrolled hypertension.
This was the topic of discussion during this afternoon’s session at Practical Updates in Primary Care 2020. The session was led by Michael Bloch, MD, who is an associate professor in the Department of Medicine at the University of Nevada School of Medicine and runs the Vascular Care Clinic at the Renown Institute for Vascular Health in Reno, Nevada.
The first topic Dr Bloch spoke about was pseudoresistance and how to identify it. The 2018 AHA Scientific Statement on Resistant Hypertension defines resistant hypertension as “Blood pressure that remains above 140/90 mm Hg in patients who are adhering to an adequate and appropriate triple-drug regimen (including a diuretic) where all drugs are prescribed at near-maximum recommended doses.”
Dr Bloch defined the types of pseudoresistance as inaccurate blood pressure measurement, poor adherence to medications or diet, and white-coat hypertension.
“The more medications we prescribe, the less likely patients are to adhere to all of them. And, of course, medications only work when you take them,” Dr Bloch said.
He also said that antihypertensive medication nonadherence rates are linked to poor outcomes, including higher risk of developing heart failure, coronary artery disease, and cerebrovascular disease.
He then briefly talked about lifestyle modifications, with a focus on salt intake.
“Patients who have resistant hypertension are very sodium sensitive because of changes that have happened in the nephron and other reasons. If you can change these patients to a low-salt diet, you can have dramatic effects on their blood pressure,” Dr Bloch said.
Secondary Causes of Hypertension
Dr Bloch then spoke about secondary contributing factors to resistant hypertension. Some common causes include obstructive sleep apnea, renal parenchymal disease, primary aldosteronism, renal artery stenosis, and thyroid disease.
The uncommon causes that Dr Bloch mentioned included hypercortisolism, pheochromocytoma, aortic coarctation, hyperparathyroidism, and intracranial tumor. He said he would “only screen for these causes if there were specific clinical clues for that form of secondary hypertension.”
Once you have identified resistant hypertension and ruled out other causes, it is time to think about a treatment regimen, Dr Bloch said.
Referring back to the definition of resistant hypertension, Dr Bloch said to review the 3 drugs your patient is currently taking in order to build a strong foundation of pharmacological therapy. The foundation of initial pharmacological therapy, according to Dr Bloch, includes an angiotensin-converting enzyme inhibitor or angiotensin II receptor blocker, and a thiazide-type diuretic and calcium channel blocker.
The next step would be to maximize or add diuretic therapy.
“It’s ok to increase diuretic use, but you should watch electrolytes and renal function,” Dr Bloch warned.
If increasing the diuretic dose does not work, you can add spironolactone to the regimen, which has been shown to be more effective than doxazosin, bisoprolol, and placebo in reducing hypertension in a recent trial. After that, the next step would be to refer your patient to a clinical hypertension specialist.
Nonpharmacological management strategies can include device-guided breathing, transcendental meditation, isometric hand grip, and acupuncture.
“These interventions only work if they are done at regular intervals, at least a few times a week,” Dr Bloch said.
Also, endovascular renal denervation is a potential new nonpharmacological option for treating hypertension, Dr Bloch said, with increasing data showing that it can reduce blood pressure by 5 to 8 mm Hg.
“Guidelines and scientific statements are merely that—they are merely guidelines. Of course, we always need to be individualizing our approach to these patients, depending on who that patient is and their unique circumstances,” Dr Bloch concluded.
Bloch M. Clinical advances in resistant hypertension. Talk presented at: Practical Updates in Primary Care Virtual Series; November 6-7, 2020; Virtual.