Aldosterone-renin ratio and plasma renin activity as biomarkers for treatment response in resistant hypertension.

A recent randomised trial demonstrated the non-inferiority of amiloride versus spironolactone in resistant hypertension, with exploratory analyses suggesting heterogeneity in treatment response based on baseline aldosterone-renin ratio (ARR). We evaluated associations between baseline renin-aldosterone status and blood pressure-lowering responses to each agent. This post hoc subgroup analysis used data from the abovementioned trial. Among 114 patients, 113 had available ARR data and were included and stratified by median ARR into two groups. Subgroup analyses were also performed according to baseline plasma renin activity (PRA) levels. The primary endpoint was the change in home systolic blood pressure (SBP) from baseline to 12 weeks. Patients with higher ARR were older and had higher baseline SBP than those with lower ARR. Multivariate regression analysis showed that female sex, higher nighttime SBP, higher ARR, and lower PRA were associated with a greater reduction in home SBP in response to treatment. In treatment-specific analyses, the home SBP-lowering response to spironolactone was pronounced in patients with higher ARR (-18.8 ± 11.6 vs -9.8 ± 8.4 mmHg, vs. lower ARR) and lower PRA (-19.1 ± 11.8 vs. -10.1 ± 8.4 mmHg, vs. higher PRA), yielding significant ARR-by-treatment (p = 0.046) and PRA-by-treatment (p = 0.027) interactions. In contrast, the home SBP-lowering response to amiloride was not significantly different according to baseline ARR or PRA. These exploratory findings suggest that renin-aldosterone profiling may help identify biological heterogeneity in treatment and warrant prospective evaluation as a candidate tool for treatment selection in resistant hypertension. This post-hoc analysis of a randomized trial in resistant hypertension evaluated. whether renin-aldosterone status predicts differential BP responses to spironolactone versus. amiloride. Women, higher nighttime SBP, higher aldosterone-renin ratio (ARR), and lower. plasma renin activity (PRA) were associated with greater BP reduction. Spironolactone showed greater efficacy in patients with high ARR or low PRA, with significant treatment-by-ARR (p = 0.046) and treatment-by-PRA (p = 0.027) interactions. Amiloride demonstrated consistent efficacy regardless of renin-aldosterone profile. No significant between-drug difference was efficacy regardless of renin-aldosterone profile. No significant between-drug difference was observed within individual strata.