Is the Evolution of the Aldosterone-renin Ratio Pre- Versus Post-operative on Day 1 Following Unilateral Adrenalectomy for Primary Hyperaldosteronism Predictive of Blood Pressure Outcomes

Primary hyperaldosteronism is characterised by excessive and autonomous aldosterone secretion by the adrenal glands, independent of renin. The condition is characterised by an aldosterone-to-renin ratio (ARR) that exceeds a certain pathological threshold. It manifests as arterial hypertension, which is potentially associated with hypokalaemia due to increased urinary potassium excretion. Excessive and unregulated aldosterone secretion is a validated risk factor for cardiovascular complications.

Primary hyperaldosteronism is estimated to account for 5-20% of hypertension cases and up to 25% of resistant hypertension cases.

Autonomous aldosterone secretion may originate from unilateral secretion by a benign adrenal cortical tumour (Conn's adenoma). Treatment usually involves surgical removal of the hypersecretion source via unilateral adrenalectomy. Alternatively, it can correspond to bilateral adrenal secretion, with or without lateralisation (bilateral adrenal hyperplasia), which is typically managed with antihypertensive medications and/or mineralocorticoid receptor antagonists. In 2021, the HISTOALDO consensus (histology of primary aldosteronism) and the routine use of immunohistochemistry (CYP11B2) made it possible to describe all the histopathological variations between a simple cortical adrenal tumour and bilateral hyperplasia.

Primary hyperaldosteronism due to unilateral or bilateral lesions with lateralised secretion (confirmed by venous sampling or NP53 scintigraphy) usually warrants surgical management via adrenalectomy.

However, while the effectiveness of the treatment is almost guaranteed to cure hypokalaemia, blood pressure changes after surgery remain highly variable, with few criteria available to predict the impact of surgery on blood pressure. Some patients are completely cured and can discontinue all antihypertensive medications, while others experience improvement, allowing a reduction in treatment. A final group shows no change in blood pressure post-adrenalectomy.

The main objective of this study is to evaluate the predictive value of measuring hormone status (aldosterone, renin and ARR) on the first day after surgery for postoperative blood pressure outcomes (clinical criteria: Systolic Blood Pressure).