Aldosterone Reduction Rate After Saline Infusion Test May Be a Novel Prediction in Patients With Primary Aldosteronism

Abstract

Objective Accurate assessment and localization of aldosterone-producing adenomas (APAs) are essential for the treatment of primary aldosteronism (PA). Although adrenal venous sampling (AVS) is the standard method of reference for subtype diagnosis in PA, controversy exists concerning the criteria for its interpretation. This study aims to determine better indicators that can reliably predict subtypes of PA. Method Retrospective, single-cohort analysis including 209 patients with PA who were subjected to AVS. Eighty-two patients whose plasma aldosterone concentrations (PAC) were normalized after surgery were histopathologically or genetically diagnosed with APA. The accuracy of image findings was compared to AVS results. Receiver operating characteristic (ROC) curve analysis between the operated and the no-apparent laterality groups was performed using AVS parameters and loading test for diagnosis of PA. Result Agreement between image findings and AVS results was 56.3%. ROC curve analysis revealed that the lateralization index (LI) after adrenocorticotropin stimulation cutoff was 2.40, with 98.8% sensitivity and 97.1% specificity. The contralateral suppression index (CSI) cutoff value was 1.19, with 98.0% sensitivity and 93.9% specificity. All patients over the LI and CSI cutoff values exhibited unilateral subtypes. Among the loading test, the best classification accuracy was achieved using the PAC reduction rate after a saline infusion test (SIT) >33.8%, which yielded 87.2% sensitivity or a PAC after a SIT <87.9 pg/mL with 86.2% specificity for predicting bilateral PA. Conclusion The combined criteria of the PAC reduction rate and PAC after the SIT can determine which subset of patients with APA who should be performed AVS for validation.

Evaluation of various confirmatory tests for the diagnosis of aldosterone-producing adenoma

“…On the other hand, PAC reduction rate in SIT was significantly lower in patients with unilateral hypersecretion. Recently, Nagano et al demonstrated that the combination of PAC reduction rate in SIT and PAC after SIT is a useful criterion for discriminating unilateral hypersecretion from bilateral hypersecretion, 37 which is consistent with our study. Although not only our study but their study did not purely compare the diagnostic significance of each value after confirmatory tests and the value changes in the confirmatory tests, in our study, the PAC value after CCT or SIT tends to be superior to the value change of PAC in SIT.…”

Diagnostik und Therapie des Conn-Syndroms: neue Aspekte

“…Auf der anderen Seite fanden modifizierte Kriterien von Bestätigungstests auch Verwendung in der Subtypdifferenzierung. Verschiedene Studien konnten zeigen, dass anhand des Ergebnisses des Kochsalzbelastungstests mittels eines Scores eine Subtypdifferenzierung möglich ist [19,20]. Kürzlich konnten Burello und Mitarbeitende in einer großen Studie mittels "Machine Learning" Vorhersagemodelle für die PHA-Subtypdiagnostik validieren [21].…”

Recent Development toward the Next Clinical Practice of Primary Aldosteronism: A Literature Review

“…Based on the analysis of the receiver operating characteristic curve, they proposed an optimal cut-off value of PAC after seated saline infusion as 13.1 ng/dL for subtype prediction, which had a sensitivity of 0.94 and a specificity of 0.79 for unilateral PA [ 137 ]. Subsequently, Nagano et al also examined SIT-based subtype prediction, showing the potential of PAC reduction rate after saline infusion [ 138 ]. Using 209 PA cases, they demonstrated that an actual PAC less than 8.79 ng/dL after saline infusion at supine position had a sensitivity and a specificity of 0.80 and 0.86, respectively, for BHA detection, while over 33.8% PAC reduction between before and after SIT had a higher sensitivity of 0.87 [ 138 ].…”

“…Subsequently, Nagano et al also examined SIT-based subtype prediction, showing the potential of PAC reduction rate after saline infusion [ 138 ]. Using 209 PA cases, they demonstrated that an actual PAC less than 8.79 ng/dL after saline infusion at supine position had a sensitivity and a specificity of 0.80 and 0.86, respectively, for BHA detection, while over 33.8% PAC reduction between before and after SIT had a higher sensitivity of 0.87 [ 138 ]. Similarly, Hashimura et al built a prediction score using both baseline PAC and ARR reduction in SIT with a high specificity of 0.97 for distinguishing BHA, allowing 49% of the cases to circumvent AVS [ 139 ].…”

“…Thus, combination of different parameters from one confirmatory test could achieve more accurate subtyping than single point measurement of PAC. Comparing with SIT, the captopril challenge and the furosemide upright tests tended to have a slightly lower ability for subtype prediction [ 138 , 140 ].…”