Primary aldosteronism: making sense of partial data sets from failed adrenal venous sampling-suppression of adrenal aldosterone production can be used in clinical decision making

Background: It has been suggested that accurate clinical decisions may be made in patients with primary aldosteronism (PA) in the setting of failed cannulation of an adrenal vein, thereby utilizing only data from either right or left adrenal venous sampling (AVS) alone. Methods: Retrospective analysis was performed for all patients with PA who underwent successful bilateral AVS. Adrenal vein/inferior vena cava index (AV/IVC index) was calculated by dividing aldosterone/cortisol ratio of the adrenal vein by aldosterone/cortisol ratio in the inferior vena cava, as described in a previously published study. We examined the rates of inappropriate adrenalectomy and failure to recognize unilateral disease when previously published cutoffs are used. Results: Inclusion criteria were met in 150 patients; 61 with bilateral and 89 with unilateral disease. AV/IVC index cutoff of ≤0.5 to predict contralateral disease would have not led to any inappropriate adrenalectomies and would have missed 19% of patients with unilateral disease; AV/IVC index cutoff of ≥5.5 to predict ipsilateral unilateral disease would have resulted in inappropriate adrenalectomy in 18% of patients (95% CI 8–34%, P <.01) and would have not recognized 55% of patients with unilateral disease (P <.01). Conclusion: The cortisol-corrected adrenal vein/inferior vena cava aldosterone index with a cutoff value of ≤0.5 performed well in identifying patients with contralateral unilateral disease. AV/IVC index of ≥5.5 cannot be used to reliably diagnose ipsilateral unilateral disease because 18% of patients undergoing adrenalectomy based on this cutoff would have bilateral disease.