We aimed to evaluate the effect of mineralocorticoid receptor antagonists on aldosterone-to-renin ratio in patients with primary aldosteronism.We prospectively enrolled 121 patients with confirmed primary aldosteronism who started a mineralocorticoid receptor antagonist (canrenone) treatment. Eighteen patients (11 with unilateral and 7 with bilateral primary aldosteronism) composed the short-term study cohort and underwent aldosterone, renin and potassium measurement after 2 and 8 weeks of canrenone therapy. The long-term cohort comprised 102 patients (16 with unilateral and 67 with bilateral primary aldosteronism, and 19 with undetermined subtype) who underwent hormonal and biochemical re-assessment after 2 to 12 months of canrenone therapy.Renin and potassium levels showed a significant increase, and aldosterone-to-renin ratio displayed a significant reduction compared with baseline after both a short and long-term treatment. These effects were progressively more evident with higher doses of canrenone and after longer periods of treatment. We demonstrated that canrenone exerted a deep impact on the diagnostic accuracy of the screening test for primary aldosteronism: the rate of false negative tests raised to 16.7%, 38.9%, 54.5% and 72.5% after 2 weeks, 8 weeks, 2-6 months and 7-12 months of mineralocorticoid receptor antagonist treatment, respectively.Mineralocorticoid receptor antagonists should be avoided in patients with hypertension before measurement of renin and aldosterone for screening of primary aldosteronism.
Alessio Pecori, Fabrizio Buffolo, Jacopo Burrello, Giulio Mengozzi, Francesca Rumbolo, Valeria Avataneo, Antonio D'Avolio, Franco Rabbia, Chiara Bertello, Franco Veglio, Paolo Mulatero, Silvia Monticone