Primary and "Pre-Primary" Aldosteronism in Resistant Hypertension: A Practical, Pragmatic, and Prudent Approach in Resource-Limited Milieu.

Introduction Primary aldosteronism (PA), once considered rare, is now recognized as the most common cause of secondary hypertension, accounting for almost a quarter of resistant hypertension (RH) cases. Despite this, PA remains underdiagnosed, with an extremely low percentage of RH patients undergoing screening. Methods In a specialty diabetes-endocrinology clinic, the aldosterone:renin ratio (ARR) was assessed in 115 consecutive RH patients (ages 21-93 years; 47% male; 87% with type 2 diabetes). Fasting blood samples were drawn in a standing position after 30 minutes of walking. Adrenal imaging (CT/MRI) was performed for those with an ARR >20. Results ARR values ranged from 0.4 to 227 (ARR <10 (35%); 11-20 (19%), 21-40 (25%), and >40 (21%)), with corresponding stepwise decreasing plasma renin activity (PRA) (P= 1E-6) and increasing serum aldosterone (SA) (P= 8E-7). Increasing ARR tended to be associated with an increase in serum creatinine (R= 0.23; P= 0.03) and a decrease in estimated glomerular filtration rate (eGFR) (R= -0.24; P= 0.02) and an increase in urine albumin: creatinine ratio. The ARR> 40 group displayed the highest serum creatinine, lowest eGFR, higher urine albumin: creatinine ratio, highest serum sodium, lowest serum potassium, and highest (44%) abnormal adrenal imaging (bilateral hyperplasia diffuse/nodular; solitary adenoma), reflecting a later stage of the pathological spectrum. PA treatment with mineralocorticoid receptor antagonists (MRAs) had a salutary effect. Conclusions Our observations further reinforce that PA is not a binary condition, but exists as a spectrum disorder responsive to MRAs, even in patients with mildly elevated or normal aldosterone levels. Early disease detection/recognition ("renin-independent aldosterone production") can be facilitated by marking "pre-primary" aldosteronism (ARR 11-20), followed by monitoring progression (periodic rescreening) and optimizing treatment, with hopeful mitigation of end-organ damage in RH.