Detecting primary aldosteronism in Australian primary care: a prospective study

Objective: To assess the identification of primary aldosteronism (PA) in newly diagnosed, treatment-naïve patients with hypertension by screening in primary care. Design: Prospective study. Setting: General practices in the South Eastern Melbourne Primary Health Network with at least three general practitioners and general practices elsewhere in Victoria that had referred patients to the Endocrine Hypertension Clinic at Monash Health, 2017‒2020. Participants: Adults (18–80 years) with newly diagnosed hypertension (measurements of systolic blood pressure > 140 mmHg or diastolic blood pressure > 90 mmHg on at least two occasions) and not taking antihypertensive medications were screened for PA by assessing their aldosterone-to-renin ratio (ARR). Participants with two ARR values exceeding 70 pmol/mU underwent saline suppression testing at the Endocrine Hypertension Service (Monash Health) to confirm the diagnosis of PA. Main outcome measures: Prevalence of PA (number of patients with confirmed PA divided by number screened). Results: Sixty-two of 247 screened participants had elevated ARR values on screening (25%); for 35 people (14%; 95% CI, 10–19%), PA was confirmed by saline suppression testing. Baseline characteristics (mean age, sex distribution, median baseline blood pressure levels, and serum potassium concentration) were similar for people with or without PA. Conclusion: PA was diagnosed in 14% of patients with newly diagnosed hypertension screened by GPs, indicating a potential role for GPs in the early detection of an important form of secondary hypertension for which specific therapies are available.