Performance of aldosterone-to-renin ratio before washout of antihypertensive drugs in screening of primary aldosteronism.

ABSTRACT

OBJECTIVE: The aim of this study is to evaluate performance of aldosterone-to-renin ratio (ARR) before washout of antihypertensive drugs as a screening test for primary aldosteronism (PA). METHODS: This retrospective analysis included consecutive patients suspected of having secondary hypertension during a period from January 2017 to May 2022 at authors' institute. For inclusion in the final analysis, ARR must be available prior to as well as after discontinuation of antihypertensives. Patients with ARR ≥2.4(ng/dL)/(µIU/mL) after washout proceeded to confirmatory tests. Diagnosis of PA was established based on positive result of the confirmatory test. Diagnostic accuracy of ARR prior to the washout in predicting PA are shown as sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV). RESULTS: The analysis included a total of 1306 patients [median age of 50.2 (41.0-59.0) years, 64.0% male]. Confirmatory tests showed PA in 215(16.5%) patients and essential hypertension (EH) in the remaining 1091(83.5%) patients. In comparison to the second screening test, the first screening test (before washout of antihypertensives) yielded lower plasma aldosterone and higher renin, and consequently lower ARR in both the PA and EH groups. At a cutoff of 0.7(ng/dL)/(µIU/ml), ARR before washout had 96.3% sensitivity, 61.2% specificity, 0.33 PPV and 0.99 NPV. At a lower cutoff of 0.5(ng/dL)/(µIU/ml), the sensitivity, specificity, PPV and NPV are 97.7%, 52.0%, 0.29 and 0.99. CONCLUSIONS: ARR prior to washout of antihypertensives is a sensitive screening test for PA. Washout of antihypertensives could be omitted and further investigation for PA is not warranted if ARR was ≤ 0.7(ng/dL)/(µIU/ml) before washout.