Resistant hypertension (HT) is a vexing problem and accounts for approximately 10% of all cases of HT. According to European
and American Heart Association/American College of Cardiology guidelines, it is defined as blood pressure (BP) above target
levels despite optimal dosing of three antihypertensive medications of which one is a thiazide diuretic. The other two are most
often a calcium channel blocker and an angiotensin-converting enzyme inhibitor/angiotensin receptor blocker. It is imperative to
first rule out all causes of pseudoresistant HT such as inaccurate BP measurement, prominent white coat effect, poor medication
compliance, and inadequate optimization of treatment. Contributing lifestyle factors and secondary causes of HT must also be
looked for and corrected before labeling the patient as having resistant HT. Investigations should include basic tests to evaluate
for end-organ damage and in selected cases tests to rule out the common secondary causes such as sleep disorders, primary
hyperaldosteronism, chronic kidney disease, and renovascular HT. When treating such patients, the first step is to change from
hydrochlorothiazide to chlorthalidone or indapamide which are more effective diuretics. If a fourth drug is to be added, the strategy
of choice is to add a mineralocorticoid receptor antagonist such as spironolactone eplerenone or amiloride. Beta-blockers, alphablockers,
centrally acting drugs such as clonidine, and vasodilators such as hydralazine are other medicines that can be used for
very resistant cases. For patients with very stubborn HT, newer interventional modalities may be tried. Among these, the most
investigated is renal (sympathetic) denervation by either ultrasound or radiofrequency ablation. Another newer target is carotid
baroreceptor modulation. Although an exciting frontier in the treatment of resistant HT, their efficacy, safety, and exact role await
further randomized studies.
Key words: Drug therapy mineralocorticoids, interventional treatment, pseudoresistant hypertension, resistant hypertension
How to cite this article: Pinto RJ. The Perplexing Problem of
Resistant Hypertension - Evaluation and Treatment (Review).
Hypertens 2020;6(2):79-86.
Received: 14-05-2020;
Accepted: 30-05-2020