title: The Intra-Procedural Cortisol Assay During Adrenal Vein Sampling: Rationale and Design of a Randomized Study (I-Padua).
abstract: BACKGROUND
  Adrenal vein sampling (AVS) is the gold standard test for the subtyping of primary aldosteronism (PA). This procedure is hampered by unsuccessful bilateral cannulation of adrenal veins in up to two thirds of the cases depending on the cutoff of the selectivity index used. The rapid intra-procedural cortisol assay (IRCA) can increase the rate of bilateral success of AVS. This hypothesis needs to be proven using a randomized prospective study approach.
  
  
  OBJECTIVE
  We will therefore evaluate if an IRCA guiding adrenal vein sampling can increase the rate of selectivity and success of adrenal vein catheterization.
  
  
  METHODS
  Consecutive patients with a biochemical diagnosis of PA and seeking surgical cure will be randomized to undergo AVS according to the usual practice with or without IRCA. The primary endpoint of the study will be the rate of bilaterally selective AVS studies, as defined by a value of the selective index >2.00 under baseline (unstimulated) conditions. With a total of 200 patients submitted to AVS, e.g. 100 patients in each arm, the study has 82% power to detect a 18% difference between arms at a two-sided α level =0.05.
  
  
  RESULTS
  Given this power the study should allow to conclusively determine if IRCA is useful or not for improving the success rate of AVS. From the clinical standpoint this will be a major accomplishment in the field of the subtyping of PA considering the current disastrous situation regarding the clinical use of AVS.
authors.affiliation: Department of Medicine-DIMED, Clinica dell'Ipertensione Arteriosa, University of Padova, Padua, Italy.
authors.forename: Maurizio
authors.initials: M
authors.lastname: Cesari
authors.affiliation: Department of Medicine-DIMED, Clinica dell'Ipertensione Arteriosa, University of Padova, Padua, Italy.
authors.forename: Giulio
authors.initials: G
authors.lastname: Ceolotto
authors.affiliation: Department of Medicine-DIMED, Clinica dell'Ipertensione Arteriosa, University of Padova, Padua, Italy.
authors.forename: Giacomo
authors.initials: G
authors.lastname: Rossitto
authors.affiliation: Department of Medicine-DIMED, Clinica dell'Ipertensione Arteriosa, University of Padova, Padua, Italy.
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Maiolino
authors.affiliation: Department of Medicine-DIMED, Clinica dell'Ipertensione Arteriosa, University of Padova, Padua, Italy.
authors.forename: Teresa Maria
authors.initials: TM
authors.lastname: Seccia
authors.affiliation: Department of Medicine-DIMED, Clinica dell'Ipertensione Arteriosa, University of Padova, Padua, Italy. gianpaolo.rossi@unipd.it.|Department of Medicine-DIMED, Hypertension Clinic, University Hospital, Via Giustiniani, 35128, Padua, Italy. gianpaolo.rossi@unipd.it.
authors.forename: Gian Paolo
authors.identifier: http://orcid.org/0000-0002-4687-8033
authors.initials: GP
authors.lastname: Rossi
mesh_terms: D000304:Adrenal Cortex Function Tests; D000311:Adrenal Glands / Q000098:blood supply*; D015415:Biomarkers / Q000097:blood; D001800:Blood Specimen Collection / Q000379:methods*; D002985:Clinical Protocols; D006801:Humans; D006854:Hydrocortisone / Q000097:blood*; D006929:Hyperaldosteronism / Q000097:blood / Q000175:diagnosis*; D007558:Italy; D011237:Predictive Value of Tests; D011446:Prospective Studies; D018401:Sample Size; D014680:Veins
chemical_list: D015415:Biomarkers; D006854:Hydrocortisone
keywords: Adrenal vein sampling; Cortisol assay; Primary aldosteronism; Procedure