RAS-challenge as a first-look test for detection of primary aldosteronism in patients with treatment-resistant hypertension.

ABSTRACT

PURPOSE: Primary aldosteronism (PA), characterised by low-renin hypertension, confers a high cardiovascular risk and is the most common cause of secondary hypertension, with an increased prevalence in patients with treatment-resistant hypertension. However, it is estimated that only a small percentage of affected patients are identified in routine clinical practice. Inhibitors of the renin-angiotensin system cause an increase in renin levels in patients with intact aldosterone regulation, and inadequate low renin with concurrent RAS inhibition (RASi) may therefore indicate PA, which could serve as a first look screening test for selection for formal work-up. METHODS: We analysed patients between 2016-2018 with treatment-resistant hypertension who had inadequate low renin in the presence of RASi (i. e. at risk for PA) and who were offered systematic work-up with adrenal vein sampling (AVS). RESULTS: A total of 26 pts were included in the study (age 54.8 ± 11, male 65%). Mean office blood pressure (BP) was 154/95 mmHg on 4.5 antihypertensive drug classes. AVS had a high technical success rate (96%) and demonstrated unilateral disease in the majority of patients (57%), most of which (77%) were undetected by cross-sectional imaging. CONCLUSION: In patients with resistant hypertension, low renin in the presence of RASi is a strong indicator for autonomous aldosterone secretion. It may serve as an on-medication screening test for PA to select for formal PA work up.

What is the context? Primary aldosteronism (PA) is associated with an uncontrolled secretion of the hormone aldosterone and often causes severe forms of high blood pressure. PA is considered the most common cause of high blood pressure which is caused by another medical condition. Medical societies have issued precise recommendations for the screening of this disease, which includes the determination of aldosterone and its main regulator renin. However, it is estimated that only a small percentage of affected patients are identified in routine clinical practice.What is the problem? In clinical studies, the determination of renin, aldosterone and its ratio (ARR) proved to be a valid screening tool. Nevertheless, in everyday life assessing and interpreting these results can be challenging for the clinician. The ARR is influenced by all first-line antihypertensives and in case of doubt, an extensive change in medication is recommended. Especially patients with resistant hypertension may require intensive medical care when medication is changed.What is important? In this study, we analysed patients at risk for PA who had inadequate low renin in presence of RASi (ACE inhibitors, Angiotensin receptor blockers). This study suggests that in patients with severe hypertension, the determination of renin in presence of RASi can provide further information on the presence of autonomic aldosterone secretion at a glance. However, this approach cannot and should not replace the algorithm proposed by current guidelines. In contrast, this approach should be an easy-to-implement concept that should prime the initiation of further appropriate diagnostics.