High dietary sodium blunts effects of mineralocorticoid receptor antagonism on left ventricular hypertrophy regression in patients with resistant hypertension

Purpose of Study: Patients with resistant hypertension (RHTN) commonly have primary aldosteronism (PA), which is associated with left ventricular hypertrophy (LVH). Aldosterone activates mineralocorticoid receptors (MR) and induces hypertrophy. Experimental studies indicate a paradoxical activation of the MR in sodium-loaded rats despite adequate suppression of aldosterone. MR antagonists slow down cardiac hypertrophy. We hypothesized that the MR anatagonist spironolactone (SPL) would cause greater LVH reduction in patients on high sodium (Na) diet independent of aldosterone. Methods Used: Overall 34 patients with RHTN, defined as BP 140/90 mmHg despite 3 different medications, including a diuretic, were treated with SPL. Cardiac magnetic resonance imaging and biochemical evaluation was performed at baseline, 3 and 6 months in patients with PA and non-PA. PA was defined as renin activity (PRA)