The diagnostic pathway for primary aldosteronism (PA) involves screening with an aldosterone-renin ratio (ARR); confirmatory testing with a saline suppression test (SST); and subtyping with adrenal venous sampling (AVS). Medication switching may be required as commonly used anti-hypertensives affect renin and/or aldosterone, with the potential to cause false results. Our study aims to evaluate the role of medication switching and full diagnostic workup of PA in elderly patients.
Clinical and biochemical data were collected retrospectively for patients who attended the Endocrine Hypertension Service at Monash Health between May 2016 to December 2019. Participants were stratified into elderly ( 65 years) and non-elderly (< 65 years) groups, and further divided according to treatment received and PA subtype.
The study participants (n = 306) were stratified into elderly (n = 76, median age 71 years) and non-elderly (n = 230, median age 56 years) groups. Elderly patients less frequently underwent medication switching (29/76, 45% vs 118/230, 74%) or full diagnostic workup with AVS (18/76, 24% vs 107/230, 47%) compared to non-elderly patients. Elderly patients who received empirical mineralocorticoid receptor antagonist (MRA) treatment without undergoing SST or AVS had similar outcomes to those who received MRA following full workup, with comparable systolic blood pressure (140 mmHg vs 129 mmHg), serum potassium (4.6 mmol/L vs 4.7 mmol/L) and plasma renin concentration (13 mU/L vs 15 mU/L) following initiation of MRA therapy. However, the empirically treated group continued to take more anti-hypertensive medications (3 compared to 1 ).
Our study demonstrated that complete PA workup in elderly patients may lead to a greater reduction in the number of anti-hypertensive medications required for blood pressure control. However, when full diagnostic workup is not feasible, empirical MRA treatment may lead to similar clinical and biochemical outcomes.