Definition of Resistant Hypertension.
The most common cause of resistant HTN non-adherence.
Diagnosis
H&P:
-Identify and reversible risk factors such as obesity/overweight, lack of exercise, high salt diet, increased alcohol intake.
-Screen for OSA and treat if present.
-Check for meds that may be contributing to HTN and d/c if possible.
-Workup for secondary HTN.
–DDx of Resistant Hypertension.
-Consider Urine drug screen
Treatment
A low-salt diet, limit of alcohol intake, exercise, wt loss (if needed), tx OSA if present.
Step1: Use ACT. Use 3 or more drugs for treatment. If there is no specific indication for a class of drugs (e.g. BB or no non-dihydropyridine CCB for rate control in a-fib), use 1) ACE inhibitor or ARB, 2) a long-acting CCB such as amlodipine, and 3) a long-acting thiazide diuretic, preferably chlorthalidone. If the patient is on HCTZ, switch to chlorthalidone and then add other drugs, as necessary.
-If the eGFR < 30 mL/min per 1.73 m2, a loop diuretic, such as furosemide or torsemide, is usually necessary for effective volume control.
Step 2: Add Spironolactone. If the patient still has resistant HTN after using the ACT combination of three drugs, then add spironolactone. Start at 12.5 mg/day and titrate up to, but not above, 50 mg/day in the absence of proven primary aldosteronism. If a patient cannot tolerate spironolactone, use eplerenone or amiloride.
-Monitor serum K+ levels for both hypokalemia and hyperkalemia if chlorthalidone and spironolactone are used.
-If the patient is still hypertensive, add a vasodilating beta-blocker e.g. a centrally acting agent such as guanfacine or a clonidine transdermal patch.
-Among patients who remain resistant, a direct vasodilator such as hydralazine for women or minoxidil for men may be used.
-Will consider specialist referral early.
**If the current regimen includes a drug not from the three recommended drug classes (ACT), add the missing ACT preferred drug and assess the response. Don’t discontinue any drugs, as long as they are well tolerated, before achieving blood pressure control.
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Obstructive sleep apnea is the most common cause(association) with resistant hypertension.
“Obstructive sleep apnea is found in 30%–40% of hypertensive patients and 60%–70% of patients with resistant hypertension, whereas primary aldosteronism is present in only 7%–20% of patients with resistant hypertension. Renal artery stenosis is seen in 2%–24% of cases of resistant hypertension in various studies, renal parenchymal disease in 2%–4%, and thyroid disease in less than 1%.” ABFM
References
https://www.ncbi.nlm.nih.gov/pubmed/24893089
https://jamanetwork.com/journals/jama/article-abstract/1877189