title: A NEW CLINICAL PREDICTION CRITERION ACCURATELY DETERMINES A SUBSET OF PATIENTS WITH BILATERAL PRIMARY ALDOSTERONISM BEFORE ADRENAL VENOUS SAMPLING.
abstract: OBJECTIVE
  Adrenal venous sampling (AVS) is the only available method to distinguish bilateral from unilateral primary aldosteronism (PA). AVS has several drawbacks, so it is reasonable to avoid this procedure when the results would not affect clinical management. Our objective was to identify a clinical criterion that can reliably predict nonlateralized AVS as a surrogate for bilateral PA that is not treated surgically.
  
  
  METHODS
  A retrospective diagnostic cross-sectional study conducted at Slovenian national endocrine referral center included 69 consecutive patients (mean age 56 ± 8 years, 21 females) with PA who underwent AVS. PA was confirmed with the saline infusion test (SIT). AVS was performed sequentially during continuous adrenocorticotrophic hormone (ACTH) infusion. The main outcome measures were variables associated with nonlateralized AVS to derive a clinical prediction rule.
  
  
  RESULTS
  Sixty-seven (97%) patients had a successful AVS and were included in the statistical analysis. A total of 39 (58%) patients had nonlateralized AVS. The combined criterion of serum potassium ≥3.5 mmol/L, post-SIT aldosterone <18 ng/dL, and either no or bilateral tumor found on computed tomography (CT) imaging had perfect estimated specificity (and thus 100% positive predictive value) for bilateral PA, saving an estimated 16% of the patients (11/67) from unnecessary AVS. The best overall classification accuracy (50/67 = 75%) was achieved using the post-SIT aldosterone level <18 ng/dL alone, which yielded 74% sensitivity and 75% specificity for predicting nonlateralized AVS.
  
  
  CONCLUSIONS
  Our clinical prediction criterion appears to accurately determine a subset of patients with bilateral PA who could avoid unnecessary AVS and immediately commence with medical treatment.
authors.forename: Tomaz
authors.initials: T
authors.lastname: Kocjan
authors.forename: Andrej
authors.initials: A
authors.lastname: Janez
authors.forename: Milenko
authors.initials: M
authors.lastname: Stankovic
authors.forename: Gaj
authors.initials: G
authors.lastname: Vidmar
authors.forename: Mojca
authors.initials: M
authors.lastname: Jensterle
mesh_terms: D000311:Adrenal Glands / Q000098:blood supply*; D000324:Adrenocorticotropic Hormone / Q000008:administration & dosage; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D006929:Hyperaldosteronism / Q000097:blood / Q000175:diagnosis*; D008297:Male; D008875:Middle Aged; D018962:Phlebotomy / Q000379:methods*; D010912:Pituitary-Adrenal Function Tests / Q000379:methods; D011237:Predictive Value of Tests; D011379:Prognosis; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012680:Sensitivity and Specificity
chemical_list: D000324:Adrenocorticotropic Hormone