Diagnostic Accuracy of the Aldosterone–to–Active Renin Ratio for Detecting Primary Aldosteronism

Abstract

Context The aldosterone–to–active renin ratio (AARR) is the recommended screening test for primary aldosteronism (PA), but prospective study data on its sensitivity and specificity are sparse. Objective To investigate the diagnostic accuracy of the AARR for detecting PA. Design Prospective diagnostic accuracy study. Setting This study was conducted from February 2009 to August 2015 at the outpatient clinic of the Department of Endocrinology and Diabetology of the Medical University of Graz, Austria. Participants Four hundred patients with arterial hypertension who were referred to a tertiary care center for screening for endocrine hypertension. Intervention Participants had a determination of the AARR (index test) and a second AARR determination followed by a saline infusion test (SIT) after 2 to 6 weeks. PA was diagnosed in individuals with any AARR ≥3.7 ng/dL/µU/mL [including a plasma aldosterone concentration (PAC) of ≥9 ng/dL] who had a PAC ≥10 ng/dL after the SIT. We did not substantially alter antihypertensive drug intake. Main Outcome Measures Primary outcome was the receiver-operating characteristic (ROC) curve of the AARR in diagnosing PA. Results A total of 382 participants were eligible for analyses; PA was diagnosed in 18 (4.7%) patients. The area under the ROC curve of the AARR in detecting PA was 0.973 (95% CI, 0.956 to 0.990). Sensitivity and specificity for a positive AARR in diagnosing PA were 100% (95% CI, 81.5% to 100.0%) and 89.6% (95% CI, 86.0% to 92.5%), respectively. Conclusions The AARR has good diagnostic accuracy for detecting PA.

The Effect of Antihypertensive Medications on Testing for Primary Aldosteronism

“…The test was broadly used since then and is recommended for the initial evaluation of patients with suspicion of PA by the current guidelines ( Funder et al, 2016 ; Rossi et al, 2020a ). According to the most recent studies, the test has the sensitivity of 100% and the specificity of 89.6% ( Pilz et al, 2019 ). It performs better than the assessment of potassium, aldosterone or renin separately ( Rossi et al, 2020a ).…”

Primary aldosteronism 2.0: an update for clinicians on diagnosis and treatment

“…51 Detailed measurements of several components of the RAAS (of note, several angiotensins can be determined), referred to as RAS -Fingerprint, may also be useful for the diagnosis of PA and further treatment guidance, along with detailed steroid profiling, other steroids (eg, marinobufagenin), with reference to its principal stimulus, renin. 5,14,29,31,41, 42 Blood collections for determination of PAC and renin (measured either as direct renin concentration or plasma renin activity) should be preferentially performed in a usual ambulatory setting (in the morning and in a seated position) on liberal sodium intake and in a potassium-replete state. 5,22 Several factors including, for example, medications, posture, or serum potassium, can affect aldosterone, renin, and ARR (TAbLE 1), and there is also significant variability with respect to assay methods and thresholds.…”