Is adrenal venous sampling always necessary to differentiate between unilateral and bilateral primary aldosteronism? Lesson from the SPAIN-ALDO register

PURPOSE

To evaluate whether the clinical, biochemical and radiological features of patients with primary aldosteronism (PA) can predict both main subtypes of PA.

METHODS

A retrospective multicenter study of PA patients followed in 27 Spanish tertiary hospitals (SPAIN-ALDO Register). Only patients with confirmed unilateral or bilateral PA based on adrenal venous sampling (AVS) and/or postsurgical biochemical cure after adrenalectomy were included. Supervised regression techniques were used for model development.

RESULTS

328 patients [270 unilateral PA (UPA), 58 bilateral PA (BPA)] were included. The area under the curve (AUC) for aldosterone/potassium ratio and aldosterone responses following saline infusion test were 0.602 [95%CI 0.520 to 0.684] and 0.574 [95% CI 0.446-0.701], respectively, to differentiate UPA from BPA. The AUC was 0.825 [95% 0.764-0.886] when the prediction model with seven parameters - comorbidities (dyslipidemia, cerebrovascular disease, sleep apnea syndrome [SAS]), systolic blood pressure (SBP), plasma aldosterone levels (PAC), hypokalemia and unilateral adrenal nodule >1 cm and normal contralateral adrenal gland on CT/MRI - was used. In patients without comorbidities, hypokalemia, SBP > 160 mmHg, PAC > 40 ng/dL, and unilateral adrenal lesions were associated with a likelihood of having a UPA of 98.5%. The chance of BPA was higher in individuals with comorbidities, SBP < 140 mmHg, normokalemia, low PAC levels, and no adrenal tumors on the CT/MRI (91.5%).

CONCLUSION

A combination of high PAC, SBP > 160 mmHg, low serum potassium, a unilateral adrenal nodule>1 cm and no comorbidities could predict a UPA with a 98.5% accuracy.

Autonomous cortisol secretion in patients with primary aldosteronism: prevalence and implications on cardiometabolic profile and on surgical outcomes

Purpose

The aim of this study was to evaluate the prevalence of autonomous cortisol secretion (ACS) in patients with primary aldosteronism (PA) and its implications on cardiometabolic and surgical outcomes.

Methods

This is a retrospective multicenter study of PA patients who underwent 1 mg dexamethasone-suppression test (DST) during diagnostic workup in 21 Spanish tertiary hospitals. ACS was defined as a cortisol post-DST >1.8 µg/dL (confirmed ACS if >5 µg/dL and possible ACS if 1.8-5 µg/dL) in the absence of specific clinical features of hypercortisolism. The cardiometabolic profile was compared with a control group with ACS without PA (ACS group) matched for age and DST levels.

Results

The prevalence of ACS in the global cohort of patients with PA (n = 176) was 29% (ACS-PA; n = 51). Ten patients had confirmed ACS and 41 possible ACS. The cardiometabolic profile of ACS-PA and PA-only patients was similar, except for older age and larger tumor size of the adrenal lesion in the ACS-PA group. When comparing the ACS-PA group (n = 51) and the ACS group (n = 78), the prevalence of hypertension (OR 7.7 (2.64-22.32)) and cardiovascular events (OR 5.0 (2.29-11.07)) was higher in ACS-PA patients than in ACS patients. The coexistence of ACS in patients with PA did not affect the surgical outcomes, the proportion of biochemical cure and clinical cure being similar between ACS-PA and PA-only groups.

Conclusion

Co-secretion of cortisol and aldosterone affects almost one-third of patients with PA. Its occurrence is more frequent in patients with larger tumors and advanced age. However, the cardiometabolic and surgical outcomes of patients with ACS-PA and PA-only are similar.