Use of peripheral plasma aldosterone concentration and response to ACTH during simultaneous bilateral adrenal veins sampling to predict the source of aldosterone secretion in primary aldosteronism

Abstract

Context: Previous studies suggested that plasma aldosterone (PAC) response to ACTH stimulation could predict the subtypes of primary aldosteronism (PA) and avoid adrenal venous sampling (AVS).

Objective: Assess the usefulness of peripheral (P) PAC response to ACTH stimulation during AVS to identify the source of aldosterone in patients with PA.

Methods: Two hundred and fifteen patients were assigned to four different lateralization ratio (LR) groups based on different combinations of basal (≥ or <2) and post-ACTH LR (≥ or <4). The P vein parameters analysed included as follows: mean basal PAC, maximal PAC (PAC_max ), and PAC/C ratio (PAC_max /C), PAC absolute increase, PAC relative increase following ACTH bolus (250 mcg IV) and maximal variation of PAC/C ratio between post-ACTH and basal measures.

Results: Mean basal PAC was significantly higher in group 1 (basal LR > 2 and post-ACTH > 4) than in group 2 (basal LR > 2, post-ACTH < 4) or group 4 (basal LR < 2 post-ACTH < 4) (P < .001). PAC_max , PAC_max /C and PAC absolute increase following ACTH were higher in group 1 than the others (P < .017). Using receiver operating characteristic (ROC) curves analysis of groups 1 and 4, best AUC were obtained with mean basal PAC (AUC: 0.757 95% IC: 0.653-0.861), PAC_max (AUC: 0.753 95% IC: 0.646-0.860) and PAC_max /C (AUC: 0.750 95% IC: 0.646-0.853).

Conclusion: P mean basal PAC and PAC_max and PAC_max /C are higher in basal and ACTH lateralized PA than in other groups. Peripheral PAC cut-off values fail to adequately distinguish all groups and cannot replace the requirement to conduct AVS.

Keywords: ACTH stimulation; aldosterone; bilateral adrenal veins sampling; primary aldosteronism.