Basal and Post-ACTH Aldosterone and Its Ratios Are Useful During Adrenal Vein Sampling in Primary Aldosteronism.

CONTEXT: Adrenal vein sampling (AVS) is required to identify a lateralized or bilateral aldosterone source in primary aldosteronism. OBJECTIVES: Our objectives were to compare basal and post-ACTH selectivity ratio (SR) and lateralization ratio (LR) and to determine the prevalence of basal contralateral suppression and its effect on surgical outcome. PATIENTS AND INTERVENTION: Bilateral simultaneous adrenal vein samples were obtained before and after a 250-µg bolus of ACTH. Analyses were conducted on 171 technically successful AVS and on the subgroup of 66 operated patients with evaluable outcome data. RESULTS: ACTH increased selectivity on both sides from 66.7% in basal samples (SR ≥ 2) to 91.8% poststimulation (SR ≥ 5). A discordance of lateralization between basal (LR ≥ 2) and post-ACTH (LR ≥ 4) values was observed in 28% of cases, which were mostly lateralized cases basally that became bilateral post-ACTH. Basal CL suppression is present in only 30% using absolute ratio of aldosterone between the opposite (nondominant) adrenal vein and the peripheral vein AOPP/AP below 1.5 vs in 77% using aldosterone/cortisol ratio (A/C)OPP/(A/C)P below 1.5. The absence of CL suppression was associated with a lower rate of response to adrenalectomy in terms of clinical and biochemical parameters with difference in clinical cure (55% vs 13% P = .0003) and overall cure (35% vs 9%, P = .0084) using AOPP/AP, but not when using (A/C)OPP/(A/C)P. CONCLUSIONS: Stimulation with ACTH is useful to improve selectivity of AVS but can frequently modify interpretation of lateralization. Basal ratios are as important as post-ACTH ratios to set an indication of adrenalectomy. AOPP/AP is superior to (A/C)OPP/(A/C)P to assess contralateral suppression. Infrequent CL suppression reveals frequent occurrence of contralateral hyperplasia in lateralized cases and helps predict postoperative outcomes.

Adrenal Vein Sampling in Primary Aldosteronism: Sensitivity and Specificity of Basal Adrenal Vein to Peripheral Vein Cortisol and Aldosterone Ratios to Confirm Catheterization of the Adrenal Vein.

PURPOSE: To assess the sensitivity and specificity for ratios of adrenal vein cortisol level (Ca) to peripheral vein cortisol level (Cp), adrenal vein aldosterone level (Aa) to peripheral vein aldosterone level (Ap), and combined cortisol and aldosterone levels ("combined ratio") for the detection of successful adrenal vein catheterization ("selectivity") in adrenal vein sampling (AVS) without adrenocorticotropic hormone (ACTH) injection at different cutoff values. MATERIALS AND METHODS: This retrospective study was approved by the institutional review board, and informed consent was waived. AVS was performed in 160 consecutive patients (49 women and 111 men; mean age, 53.6 years) between December 1989 and January 2014. Cortisol and aldosterone levels were measured in samples from the adrenal veins and left iliac vein every 5 minutes, two times before (basal) and three times after intravenous cosyntropin (ACTH 1-24) injection. Selectivity was defined by Ca/Cp or Aa/Ap ratio of at least 5 in at least one sampling after ACTH administration. Sensitivity and specificity for the detection of selective adrenal vein catheterization were calculated for basal Ca/Cp ratio, Aa/Ap ratio, and combined ratios for three cutoff values reported in the literature. The McNemar test was used to assess differences in sensitivity and specificity to detect selective adrenal vein catheterization. RESULTS: The sensitivity and specificity for the cutoff values of at least 3, at least 2, and at least 1.1 for the detection of AVS selectivity were respectively 50.4% and 100%, 70.8% and 100%, and 98.5% and 76.9% for Ca/Cp ratio; 61.3% and 100%, 70.8% and 100%, and 94.2% and 53.8% for Aa/Ap ratio; and 75.2% and 100%, 88.3% and 100%, and 99.3% and 46.2% for combined ratios (sensitivity at the ≥2 cutoff value: P < .0001 for combined ratio vs Ca/Cp ratio and for combined ratio vs Aa/Ap ratio). CONCLUSION: Basal combined ratio has the best sensitivity for the detection of AVS selectivity at all cutoff values, and for all ratios, the cutoff value of at least 2 has the best sensitivity for 100% specificity.