100 cases of primary aldosteronism: careful choice of patients for surgery using adrenal venous sampling and CT imaging results in excellent blood pressure and potassium outcomes.

OBJECTIVE: Patients with primary aldosteronism (PA) who are suitable for surgery should undergo adrenal computerised tomography (CT) and adrenal venous sampling (AVS). A retrospective study was performed of 100 patients with PA. We determined the optimal AVS lateralisation ratio for unilateral disease and reviewed adrenalectomy outcomes evaluating which characteristics predicted hypertension cure.

METHODS: AVS was performed in 93 patients. Lateralisation criteria were assessed using ROC curve analysis. The outcome of adrenalectomy was reviewed in 39 patients and predictive factors for cure determined using univariate and multivariate analysis.

RESULTS: Of previously published criteria, ROC curve analysis found a cortisol corrected aldosterone affected to unaffected (Aldo/Cort A:U) cut-off of 2·0 was the best predictor of adenoma identifying 80·4% of patients. A novel ratio calculated by dividing the affected to unaffected ratio by the unaffected to peripheral ratio [(Aldo/Cort A:U)/(Aldo/Cort U:IVC)] was successful in identifying 87·0% of patients. Cure rate for blood pressure after adrenalectomy was 38·5% with improvement in 59·0%. On univariate analysis, predictors of post-operative hypertension were increased weight, raised creatinine, left ventricular hypertrophy (LVH) and male sex. On multivariate analysis, male sex and higher pre-operative systolic blood pressure were predictive.

CONCLUSIONS: Patients with PA should have CT scanning and AVS. Aldo/Cort A:U >2·0 is the most accurate of previously published ratios in predicting unilateral disease. When patients were carefully selected for surgery, 97% had cure or improvement in blood pressure control. Further confirmatory work is required on a novel ratio which was even more predictive in our series.