Introduction: Adrenal venous sampling (AVS) is widely used when investigating primary hyperaldosteronism. In this study we reviewed adrenal aldosterone and cortisol values for measurement range and for biochemical concordance with intervention in patients being investigated for aldosterone producing adenoma (APA).
Methods: Retrospective review of AVS procedures performed at our institution during three years (May 2016May 2019) was conducted. Aldosterone and cortisol levels, biochemical diagnosis and concordance with clinical intervention were recorded. Cortisol levels were measured using Cobas 6000® automated immune-analyzer (Roche Diagnostics, IA, USA). Aldosterone levels were performed using LCMSMS by a reference laboratory.
Results: A total of 114 patients reports were reviewed. Half (53.5%) of study patients showed lateralized APA with 65.7% to the left adrenal. Bilateral adrenal hyperplasia (BAH) reported in 40% of patients. Few patients (6.1%) showed either inconclusive findings or had unsuccessful AVS procedures. Pre-analysis dilution of 1:40 was required for cortisol. Patients with biochemical evidence for left (L)APA had lower median aldosterone and cortisol levels (4300 ng/dl and 470.2 (g/dl) compared to patients with right (R)APA (8500 ng/dl and 873.4 (g/dl) respectively. Median aldosterone cortisol ratios were similar at 12.3. Patients with BAH had significantly lower aldosterone, and cortisol ratios when compared with (L)APA (sevenfold lower) and (R)APA (4 fold lower) (P=0.00 for all). There was no significant difference (P=0.165) between right aldosterone levels and its cortisol ratio compared to patients with RAPA. However, there was significant difference for left values compared to LAPA (P=0.05). Discordance was seen in 2 patients with BAH who underwent left adrenalectomy.
Conclusion: Majority of samples had cortisol and aldosterone levels requiring much higher pre-analytical dilutions than recommended. Patients distribution may reflect of population studied and or referral criteria. Excellent concordance between biochemical diagnosis and clinical intervention was observed.