Southern Regional Meeting, New Orleans, February 18–20, 2016

362: HIGH DIETARY SODIUM BLUNTS EFFECTS OF MINERALOCORTICOID RECEPTOR ANTAGONISM ON LEFT VENTRICULAR HYPERTROPHY IN RESISTANT HYPERTENSION PATIENTS

L Ghazi

K Gaddam

LJ Dell'Italia

SG Lloyd

C Lin

D Calhoun

S Oapril

T Dudenbostel

University of Alabama at Birmingham, Birmingham, AL

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 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)<1 ng/ml/h and urinary aldosterone ≥12 ug /24 h. We dichotomized patients according to UNa level (UNa ≥200 mEq/24 h: high Na diet) and PA status. LVH reduction was indexed by left ventricular mass (LVM) and interventricular septum thickness (IVS) regression.

Summary of Results LVM and IVS regression after treatment with SPL at 3 and 6 months was greater in patients with PA on a normal sodium diet and less pronounced in patients on a high sodium diet suggesting that Na blunts the effects of cardiac MR when treated with SPL. However, in patients with non-PA high Na intake did not blunt the effects of SPL.

Conclusions Contrary to our hypothesis, high dietary Na blunted LVH regression in patients with PA treated with SPL. Further studies are needed to elucidate mechanisms for sodium dependent MR activation in patients with PA and non-PA.

Effect of spironolactone treatment in patients on LVM and in patients with and without PA at …