Performance of Primary Aldosteronism Screening Tests Before Washout of Dihydropyridine Calcium Channel Blockers: An Exploratory Retrospective Study

ABSTRACT

This retrospective cohort study preliminarily investigated the feasibility of implementing primary aldosteronism (PA) screening without discontinuing dihydropyridine calcium channel blockers (DHP‐CCBs). We screened all patients undergoing diagnostic testing for secondary hypertension from January 2017 to May 2022 at authors’ center. For inclusion, patients must be on DHP‐CCBs monotherapy for hypertension. Aldosterone and renin concentration were measured pre‐ and post‐washout. Confirmatory tests were conducted in patients with positive screen [combination of ARR >2.5 (ng/dL)/(μIU/mL), aldosterone ≥10 ng/dL, and renin ≤8.2 μIU/mL] after washout. The final analysis included a total of 198 patients (median age: 49.5 years and 117 men). Confirmatory tests identified PA in 31 (15.7%) patients. Aldosterone‐to‐renin ratio (ARR) increased in 158 (79.8%) patients after washout. In 168 patients with a negative pre‐washout screen, 22 turned positive after washout, and 14 were diagnosed PA. Consequently, the missed diagnosis rate of PA was 45.2% (14/31) when using standard positive screen criteria before washout of DHP‐CCBs monotherapy. Exploratory analysis indicated that a pre‐washout ARR cutoff of >1.2 (ng/dL)/(μIU/mL) demonstrated 0.97 sensitivity and 0.75 specificity. In conclusions, caution is warranted when interpretating screening results from patients on DHP‐CCBs monotherapy due to the potential risk of missed diagnosis. Preliminary data suggest that ARR ≤1.2 (ng/dL)/(μIU/mL) before washout may serve as a candidate threshold for excluding PA in these patients, though this observation remains a hypothesis‐generating finding that requires further investigation.