IIMAGING OF PRIMARY ALDOSTERONISM IN YOUNG PATIENTS FROM A LARGE INTERNATIONAL STUDY (AVIS-2-YOUNG)

Abstract

Objective: Purpose The Endocrine Society guidelines suggested skipping adrenal vein sampling (AVS) when referring for surgery young PA patients with a unilateral adrenal nodule and a contralateral normally appearing gland at imaging, but this was based on a limited set of cases. Hence, we sought to determining if imaging provided an accurate identification of unilateral PA. Materials and Methods: We examined the large cohort of patients ?45 years-old recruited in the AVIS-2-Young study. Biochemical cure of PA after unilateral adrenalectomy was used as the final diagnosis to assess imaging diagnostic accuracy. Results: Among the 1625 AVIS-2 patients those ?45, 40 and 35 years-old were 29.0%, 15.5% and 6.1%, respectively. In the same age cohorts, a unilateral adrenal nodule was found in 53.2%, 57.3% and 47.3%; 42.6%, 38.5% and 50.9%, respectively, showed no nodules and 4.2%, 4.2% and 1.8% bilateral nodules. In those with a unilateral nodule, the culprit adrenal was identified in 81.4%, 84.1%, and 92.3% of the patients. Youden index analysis identified ? 38 years as the best cut-off for unilateral PA identification; by restricting the analysis to those with a nodule size to > 10 mm, the overall concordance was 94.0%. However, bilateral or no nodules were detected at imaging in > 37% of the patients with a final diagnosis of unilateral PA in all age cohorts. Conclusion: Referring PA patients ?45, 40 and 35 years-old based on a unilateral nodule at imaging carried a likelihood of wrong/inappropriate surgery in 18.6%, 15.8% and 7.7%, respectively. This error rate can be minimized to 6.0% by selecting patients ?38 years with a nodule > 10 mm. However, in these age cohorts up to 1/3 of the patients, who had unilateral surgically curable PA were not detected with imaging.