An Expert Consensus Statement on Use of Adrenal Vein Sampling for the Subtyping of Primary Aldosteronism

Abstract

Abstract-Adrenal venous sampling is recommended by current guidelines to identify surgically curable causes of hyperaldosteronism but remains markedly underused. Key factors contributing to the poor use of adrenal venous sampling include the prevailing perceptions that it is a technically challenging procedure, difficult to interpret, and can be complicated by adrenal vein rupture. In addition, the lack of uniformly accepted standards for the performance of adrenal venous sampling contributes to its limited use. Hence, an international panel of experts working at major referral centers was assembled to provide updated advice on how to perform and interpret adrenal venous sampling. To this end, they were asked to use the PICO (Patient or Problem, Intervention, Control or comparison, Outcome) strategy to gather relevant information from the literature and to rely on their own experience. The level of evidence/recommendation was provided according to American Heart Association gradings whenever possible. A consensus was reached on several key issues, including the selection and preparation of the patients for adrenal venous sampling, the procedure for its optimal performance, and the interpretation of its results for diagnostic purposes even in the most challenging

Indication and Technical Aspects of Adrenal Blood Sampling

“…If the ratio is > 3, then according to the recommendations of the Conn's Registry, there is a probability of APA ( • " Table 1). If the lateralization index (LI) is > 2, then there is unilateral disease [45]. If one side cannot be sufficiently cannulated selectively, calculation of the contralateral suppression index (CSI) can sometimes indirectly verify asymmetrical aldosterone secretion [45].…”

“…If the lateralization index (LI) is > 2, then there is unilateral disease [45]. If one side cannot be sufficiently cannulated selectively, calculation of the contralateral suppression index (CSI) can sometimes indirectly verify asymmetrical aldosterone secretion [45]. An aldosterone-cortisol ratio in the sample taken from the adrenal vein less than that in the sample of peripheral blood can be interpreted to be an indication of APA on the contralateral side, and in the appropriate clinical context (such as a typical finding in the imaging study) can be assessed as unilateral disease.…”

“…Since the ACTH infusion increases the concentration gradient for cortisol and aldosterone from central to peripheral, other threshold values apply to the selectivity and lateralization indices. In this case, an SI > 3 should be presumed, above which an LI > 4 would be sufficient indication of unilateral disease [45]. We see problems related to this, since the availability of Synacthen is currently quite limited due to the sale of production rights [47] Further, the distinction between unilateral and bilateral disease can easily be blurred, since normal adrenal tissue responds with raised aldosterone secretion after administration of ACTH [48].…”

“…▶ Since the hormones under investigation show strong diurnal fluctuations, the examination should be performed early in the morning after the patient has been reclining for an extended period, as this will level out differences and decrease the specificity of the obtained data [45,51].…”

Outcomes of Drug-Based and Surgical Treatments for Primary Aldosteronism

“…93 Guidelines have recently been published, with the aim of decreasing the heterogeneity of AVS protocols and interpretation criteria, although the evidence supporting the recommendations is weak. 94 Subtype diagnosis, and hence AVS, is required only if surgery is being considered. Some factors are significantly associated with persistent hypertension after surgery: 11 being male, advanced age, familial hypertension, longer duration and higher grade of hypertension, higher body mass index, higher serum potassium concentration, lower glomerular filtration rate, higher 24h urinary aldosterone secretion, subclinical target organ damage.…”