Appraisal of the clinical trial data on renal denervation for the management of resistant hypertension

Abstract

Over the past decade several national and international societies/regulatory bodies have proposed definitions of resistant hypertension (RHTN) (Table 5.1). There are subtle differences between these definitions, but treatment-resistant systemic HTN can be described as a blood pressure (BP) that remains uncontrolled (i.e., seated office BP >140/90 mmHg) despite adherence to treatment with at least three complementary antihypertensive agents (one of which is a diuretic) already taken at optimal or best-tolerated doses [1, 3, 11, 12]. In the UK, the National Institute for Health and Care Excellence (NICE) Clinical Guideline 127 [13] (Table 5.1) has been more proscriptive with their definition by suggesting that the three antihypertensives would usually be a regimen of an angiotensin converting enzyme (ACE) inhibitor or angiotensin receptor blocker (ARB) plus a calcium channel blocker plus a thiazide-type diuretic (i.e., A+C+D regimen), in accordance with the NICE treatment algorithm. The NICE guidance has also suggested that RHTN should only be diagnosed after confirming inadequate BP control by use of ambulatory blood pressure monitoring (ABPM “ i.e., mean daytime BP >135/85), thereby excluding so-called white coat hypertension.”he optimal target BP in patients treated for RHTN is widely accepted to be <140/90 mmHg, although lower targets might be appropriate in those with diabetes and/or chronic kidney disease (CKD) (Table 5.1) [11]. Furthermore, it should be remembered that an individual whose BP is controlled by the incorporation of a 4th line agent continues to be labelled as having RHTN. Likewise, RHTN should not be confused with uncontrolled HTN, the latter being an umbrella term to include all those individuals unable to achieve adequate BP targets, including that due to non-adherence, despite therapeutic intervention.