Context: In patients who seek surgical cure of primary aldosteronism (PA), The Endocrine Society Guidelines recommend the use of adrenal vein sampling (AVS), which is invasive, technically challenging, difficult to interpret, and commonly held to be risky. Objective: The aim of this study was to determine the complication rate of AVS and the ways in which it is performed and interpreted at major referral centers. Design and Settings: The Adrenal Vein Sampling International Study is an observational, retrospective, multicenter study conducted at major referral centers for endocrine hypertension worldwide. Participants: Eligible centers were identified from those that had published on PA and/or AVS in the last decade. Main Outcome Measure: The protocols, interpretation, and costs of AVS were measured, as well as the rate of adrenal vein rupture and the rate of use of AVS. Results: Twenty of 24 eligible centers from Asia, Australia, North America, and Europe participated and provided information on 2604 AVS studies over a 6-yr period. The percentage of PA patients systematically submitted to AVS was 77% (median; 19–100%, range). Thirteen of the 20 centers used sequential catheterization, and seven used bilaterally simultaneous catheterization; cosyntropin stimulation was used in 11 centers. The overall rate of adrenal vein rupture was 0.61%. It correlated directly with the number of AVS performed at a particular center (P = 0.002) and inversely with the number of AVS performed by each radiologist (P = 0.007). Conclusions: Despite carrying a minimal risk of adrenal vein rupture and at variance with the guidelines, AVS is not used systematically at major referral centers worldwide. These findings represent an argument for defining guidelines for this clinically important but technically demanding procedure.

Primary aldosteronism is the most common form of secondary hypertension. Mutations in the KCNJ5 gene have been described recently in aldosterone-producing adenomas (APAs). The aim of this study was to investigate the prevalence of KCNJ5 mutations in unselected patients with primary aldosteronism and their clinical, biological and molecular correlates. KCNJ5 sequencing was performed on somatic (APA, n=380) and peripheral (APA, n=344; bilateral adrenal hyperplasia, n=174) DNA of patients with primary aldosteronism, collected through the European Network for the Study of Adrenal Tumors. Transcriptome analysis was performed in 102 tumors. Somatic KCNJ5 mutations (p.Gly151Arg or p.Leu168Arg) were found in 34% (129 of 380) of APA. They were significantly more prevalent in females (49%) than males (19%; P <10 ⁻³ ) and in younger patients (42.1±1.0 versus 47.6±0.7 years; P <10 ⁻³ ) and were associated with higher preoperative aldosterone levels (455±26 versus 376±17 ng/L; P =0.012) but not with therapeutic outcome after surgery. Germline KCNJ5 mutations were found neither in patients with APA nor those with bilateral adrenal hyperplasia. Somatic KCNJ5 mutations were specific for APA, because they were not identified in 25 peritumoral adrenal tissues or 16 cortisol-producing adenomas. Hierarchical clustering of transcriptome profiles showed that APAs with p.Gly151Arg or p.Leu168Arg mutations were indistinguishable from tumors without KCNJ5 mutations. In conclusion, although a large proportion of sporadic APAs harbors somatic KCNJ5 mutations, germline mutations are not similarly causative for bilateral adrenal hyperplasia. KCNJ5 mutation carriers are more likely to be females; younger age and higher aldosterone levels at diagnosis suggest that KCNJ5 mutations may be associated with a more florid phenotype of primary aldosteronism.

Remodeling of the resistance arteries is a hallmark of arterial hypertension and predicts cardiovascular events, but it was unknown whether it could also predict the blood pressure response to adrenalectomy of patients with an aldosterone-producing adenoma. Therefore, we investigated the outcome of adrenalectomy as a function of vascular remodeling in the context of the preoperative features of aldosterone-producing adenoma patients. At 2 referral centers for hypertension, we prospectively measured the media:lumen ratio of small arteries from fat tissue of 50 consecutive aldosterone-producing adenoma patients treated with adrenalectomy. The blood pressure response to adrenalectomy was assessed by considering the blood pressure values and the number and dosages of antihypertensive medications. Adrenalectomy significantly ( P <0.001) lowered plasma aldosterone (from 27.3±4.9 ng/dL to 8.3±11.2 ng/dL), the aldosterone:renin ratio (from 117±35 to 11±2), and blood pressure (from 163±22/98±2 mm Hg to 133±2/84±1 mm Hg), even despite a reduction (from 141±14 to 100±15; P =0.02) of the score of antihypertensive treatment. It provided cure of hypertension in 30% of the aldosterone-producing adenoma patients, normotension with less antihypertensive therapy in 52%, and improved blood pressure control in the rest. The media:lumen ratio and the known duration of hypertension significantly predicted the blood pressure response to adrenalectomy at univariate and multivariate analyses. Because a long duration of hypertension and/or the presence of vascular remodeling imply lower chances of blood pressure normalization at long-term follow-up postadrenalectomy, these findings emphasize the importance of an early diagnosis of aldosterone-producing adenoma.

Hypertensive kidney disease classically entails nephroangiosclerosis and hyalinosis with glomerular damage. However, in recent years, several evidences showed that high blood pressure also injures tubular cells, inducing epithelial-to-mesenchymal transition and tubulointerstitial fibrosis. Recently investigated mechanisms are also podocyte effacement and loss, which lead to denudation of the glomerular basement membrane and focal adhesion of the tufts to the Bowman's capsule, with reduced filtration and scars. Starting from the classic concept of nephroangiosclerosis, this review examines the recently emerged knowledge of new biochemical and molecular mechanisms underlying the kidney damage in hypertension and discusses how viable podocytes or podocyte-deriving proteins are promising tools for early diagnosis of renal remodelling in hypertension.

Adrenocorticotropic hormone administration was proposed to overcome the biases associated with pulsatile aldosterone secretion during adrenal venous sampling, but the usefulness of different protocols of stimulation was never systematically assessed. We, therefore, compared the effects of a high dose (HD; 250 μg IV as a bolus), a very low dose (VLD; 250 pg IV), and an intermediate dose (ID; 50 μg/h) of adrenocorticotropic hormone on the selectivity index (SI) and the lateralization index in primary aldosteronism patients, using the diagnosis of aldosterone-producing adenoma, based on pathology and follow-up data, as a reference. The HD (n=47) significantly increased plasma cortisol concentration in infrarenal inferior vena cava (+79%) blood and the SI on both sides (SI _RIGHT +113% and SI _LEFT +131%), as compared with baseline values. The ID (n=14) also markedly increased both plasma cortisol concentration inferior vena cava (+93%) and the SI (SI _RIGHT +690% and SI _LEFT +410%); the very low dose (n=6) had no effect on either the plasma cortisol concentration or SI. In the patients with unilateral aldosterone-producing adenoma, the increase of selectivity with the HD and ID was counterbalanced by a confounding effect on the correct identification of the aldosterone-producing adenoma side, which was attributed to the wrong side in 3.0% and 12.5% with HD and ID, respectively. In conclusion, the HD and the ID, but not the very low dose, adrenocorticotropic hormone stimulation protocol facilitated the ascertainment of selectivity of adrenal vein catheterization. However, this favorable effect was overridden by a confounding effect on the identification of lateralized aldosterone excess to the aldosterone-producing adenoma side. Hence, we do not recommend adrenocorticotropic hormone stimulation.

Considering the amount of novel knowledge generated in the last five years, a team of experienced hypertensionlogists was assembled to furnish updated clinical practice guidelines for the management of primary aldosteronism. To identify the most relevant studies, the authors utilized a systematic literature review in international databases by applying the PICO strategy, and then they were required to make use of only those meeting predefined quality criteria. For studies of diagnostic tests, only those that fulfilled the Standards for Reporting of Diagnostic Accuracy recommendations were considered. Each section was jointly prepared by at least two co-authors, who provided Class of Recommendation and Level of Evidence following the American Heart Association methodology. The guidelines were sponsored by the Italian Society of Arterial Hypertension and underwent two rounds of revision, eventually reexamined by an External Committee. They were presented and thoroughly discussed in two face-to-face meetings with all co-authors and then presented on occasion of the 36th Italian Society of Arterial Hypertension meeting in order to gather further feedbacks by all members. The text amended according to these feedbacks was subjected to a further peer review. After this process, substantial updated information was generated, which could simplify the diagnosis of primary aldosteronism and assist practicing physicians in optimizing treatment and follow-up of patients with one of the most common curable causes of arterial hypertension.