ODP611 Combination Of Seated Saline Suppression Test And Computed Tomography In Predicting Subtype Diagnosis Of Primary Aldosteronism In Chinese Population

Abstract

Abstract Objective The study aimed to evaluate the accuracy of the seated saline suppression test (SSST) combined with adrenal computed tomography (CT) in determining the primary aldosteronism (PA) subtypes. Methods Each patient underwent a SSST and adrenal CT. Logistic diagnostic model (CT finding + post-SSST plasma aldosterone concentration (PAC)) were built, which evaluated the accuracy of the SSST combined with adrenal CT for a subtype classification of PA. Subtype diagnosis of PA was determined by adrenal venous sampling (AVS), pathology and clinical outcomes (primary aldosteronism surgical outcome(PASO)). Results A total of 72 patients with PA were classified into two groups, including 45 aldosterone-producing adenoma (APA) and 27 idiopathic hyperaldosteronism (IHA) patients. By binary logistic regression analysis, adrenal CT (odds ratio (OR)=16.28, 95% confidence interval (CI) 4.18-63.42, P<0. 05) and 4-hours PAC after SSST (OR =1.13, 95% CI 1. 03 to 1.23, P<0. 05) were significantly independent predictors of APA patients. We have successfully developed a diagnostic model based on logistic regression that is able to predict the probability of APA. The area under the receiver operating characteristic (ROC) curve of logistic diagnostic models(AUC=0.907, 95% CI 0.815 to 0.963) was significantly greater either than that for the adrenal CT (AUC=0.807,95% CI 0.696 to 0.890,respectively,P<0. 05) or SSST (AUC=0.799,95% CI 0.688 to 0.884,respectively,P<0. 05). Positive CT finding combined with a post-SSST PAC≥18.2 ng/dL provided sensitivity of 88.89%,specificity of 74. 07%,and positive predictive value (PPV) of 93.9%(31/33) for predicting APA, that determined patients who required AVS prior to surgery. Conclusion The model combining CT finding with post-SSST PAC has superior accuracy in subtype diagnosis of PA compared with SSST or adrenal CT alone. The current study was the first study to investigate the accuracy of the new method on the subtype classification of PA. We are fortunate to find it may be a safe, convenient, sensitive and noninvasive approach in predicting subtype diagnosis of PA in Chinese individuals, especially in primary care where AVS may be unavailable. The results require further confirmation by RCT clinical trials. Presentation: Saturday, June 11, 2022 1:00 p.m. - 3:00 p.m.