Primary aldosteronism is a frequent form of secondary hypertension. Adrenal vein sampling (AVS) remains the gold standard technique to evaluate the lateralization of aldosterone secretion. Recently it has been proposed that free metanephrine is potentially a better molecule to assess the selectivity of adrenal vein sampling than cortisol in non stimulated sequential AVS.Objective:
The objective of this study was to compare cortisol to free metanephrine to assess adrenal vein selectivity using currently proposed cutoffs in non stimulated patients.Design and method:
This was a prospective monocentric study. Aldosterone, cortisol and free metanephrine were measured in patients referred for AVS using commercial immunoassays for steroids and LC/MSMS for free metanephrine. Blood samples were taken from peripheral and both adrenal veins. Phi coefficients were measured using two different cutoffs for cortisol.Results:
51 AVS from 49 patients (49% women) were included in the analysis. Mean age was 50.1 ± 9.1 years old and BMI was 28.1 ± 4.7 kg/m2. Office systolic and diastolic blood pressure were respectively 154 ± 17.1 mmHg and 91.7 ± 13.2Results:
Failure and success rate are shown in Table 1.Results:
Based on a ratio > 12 for free metanephrine, >3 or >2 for cortisol, the success rate for the right adrenal vein was respectively 85%, 42% and 59%. For the left adrenal vein the success rate was respectively 96 %, 69% and 84%. Phi coefficients were higher when a cortisol ratio > 2 was used, but remained weak.Conclusions:
This study shows that, independently, of the method used to assess selectivity, the success rate is lower for the right adrenal vein. Secondly, based on current recommended selectivity indexes for cortisol and free metanephrine, the discordance rate of successful adrenal vein sampling is high. Outcome studies based on blood response after adrenal surgery are necessary to choose the best marker of selectivity.