Resistant and Pseudoresistant Hypertension

1

What is the prevalence of resistant hypertension?

Resistant hypertension (RH) is an emerging clinical and public health problem with increasing incidence because of increasing life expectancy and the growing global epidemic of obesity, diabetes mellitus, and obstructive sleep apnea. Likewise, the excessive dietary salt ingestion reported globally in most countries can contribute substantially to the risk of RH. RH carries a considerable public health problem due to increased treatment cost associated with disability and premature deaths. From the metaanalysis by Noubiap et al. of 3.2 million patients, 10.3% (95% confidence interval [CI]: 7.6% to 13.2%) have true RH. Similarly, the prevalence of apparent treatment-resistant and pseudoresistant hypertension (pseudo-RH) were 14.7% (95% CI: 13.1% to 16.3%) and 10.3% (95% CI: 6.0% to 15.5%), respectively. Specifically, the burden of RH is highest in patients with chronic kidney disease or renal transplant and in elderly patients.

2

What is the definition of RH?

RH is defined as high blood pressure (BP) in a hypertensive patient that remains above goal despite concomitant use of three antihypertensive drugs of different classes usually including a long-acting calcium channel blocker (CCB), a blocker of the renin-angiotensin system (angiotensin-converting enzyme inhibitor [ACEi] or angiotensin receptor blocker [ARB]), and a diuretic. All antihypertensive medications should be administered at optimal or maximally tolerated doses and at the appropriate dosing frequency. Controlled RH is defined as BP that is controlled on four or less antihypertensive medications. The diagnosis of RH requires exclusion of common causes of pseudoresistance, which includes improper BP measurement technique, white coat hypertension (WCH), medication noncompliance, and treatment inertia.

This definition of RH is based on BP response to standard therapy and identifies a group of high-risk patients who may benefit from specialist care and secondary work up of hypertension. Large epidemiological studies have shown that using the above definition of RH is associated with a higher risk of adverse cardiovascular (CV) outcomes. For example, in a cohort study of 205,750 patients with incident hypertension, it was reported that the risk of CV outcomes was higher in patients with RH with a hazard ratio of 1.47 (95% CI: 1.33 to 1.62).

International hypertension guidelines have different targets for BP control for RH (e.g., the American College of Cardiology/American Heart Association [ACC/AHA] with a target of 130/80 mm Hg and the International Society of Hypertension and the European Society of Hypertension with a target of 140/90 mm Hg). For Hypertension Canada, the target for BP varies based on associated comorbid conditions (e.g., BP less than 140/90 mm Hg for those with no compelling indications, less than 130/80 mm Hg in those with diabetes, and systolic blood pressure [SBP] less than 120 mm Hg for those at high CV risk), and hence the diagnosis of RH takes this into account. See Table 27.1 for more details on the differences.