Rapid cortisol assay during adrenal vein sampling in patients with primary aldosteronism.

BACKGROUND: Adrenal vein sampling is considered the gold standard test to identify primary aldosteronism, the most frequent form of secondary hypertension. Technical difficulties with this procedure may be overcome by monitoring cortisol concentrations in the different sampling sites during catheterization.
METHODS: We applied a rapid automated cortisol assay performed on a benchtop immunoassay analyzer near the operating suite during the catheterization procedures in 5 hypertensive patients. A mean of 7.8 samples (range, 5-13) were collected from the vena cava as well as from right and left adrenal veins.
RESULTS: Cortisol concentrations measured by the rapid assay and by our routine method were comparable. Two of 5 patients were found to be affected by an aldosterone-producing adenoma and 3 of 5 by a bilateral adrenal hyperplasia. Cortisol determination during the adrenal vein sampling procedure allowed a successful cannulation in all patients, including a patient in whom it was necessary to cannulate 9 different candidate right adrenal veins before finding the correct one.
CONCLUSIONS: Intraoperative cortisol assays appeared safe, reproducible, simple to perform, rapid, and cost-effective. The approach represents a service-oriented model for the laboratory and can provide valuable and timely information for improving the success rate of adrenal vein catheterization.