Adrenal vein sampling using rapid cortisol assays in primary aldosteronism is useful in centers with low success rates

Objective: Adrenal vein sampling (AVS) is considered the gold standard in the differential diagnosis of primary aldosteronism (PA), but success rates vary between centers. We hypothesized that rapid (intraprocedure) cortisol measurement can improve performance in a center with initially low AVS success rate. Design: We analyzed 46 patients with confirmed PA studied between 2008 and 2010. Forty-seven PA patients studied between 2004 and 2008 identified by retrospective chart review served as controls. All patients were treated at a single tertiary care university hospital. Methods: Starting in 2008, rapid cortisol assays (RCA) were performed in all patients during the AVS procedure. A cortisol gradient of >= 2.0 between adrenal vein and a femoral vein sample was used as success criterion. Up to two repeat samples were drawn if adrenal vein cortisol was below this threshold. Results: During the control period 26 of 47 AVS were successful (55%). After introduction of RCA, 39 out of 46 AVS (85%) were successful (P=0.003). In 21 of the 46 cases (46%) a resampling was necessary. The increase in overall success was due to an increase in successful right AVS (85 vs 62% before introduction of RCA; P=0.02) and a training effect (P=0.024 for trend). Conclusion: RCA during AVS are useful in centers with an initially low AVS success rate.