Effects of Magnesium Replacement Therapy in Patients with Chronic Stable Heart Failure and Normal Magnesium Level

In the present study, we sought to assess the changes in functional, biochemical, and echocardiographic measurements of heart failure (HF) during a 12-week Mg2+ supplementation in chronic stable HF patients. Twenty patients with clinically stable New York Heart Association (NYHA) Class I–III systolic HF (echocardiography-derived left ventricular ejection fraction [LVEF] of <40%) and normal magnesium level (1.5–2 mg/dl) were recruited consecutively in this before and after study. The patients received oral Mg2+ (400 mg MgO b.i.d., for a total of 482.6 mg of elemental Mg2+) for a total of 12 weeks. Twenty patients, including 10 (50%) men, with a mean ± standard deviation age of 53 ± 15 years were included. The 6-min walk distance significantly increased from 379 (348–440) m to 583 (506–604) m. High-sensitivity C-reactive protein significantly decreased from 12 (7–14) to 3 (2–4) mg/dL (P < 0.001). N-terminal pro-brain natriuretic peptide also declined from 653 (415–2660.75) to 189.5 (82.5–537.75) ng/dL (P < 0.001). The LVEF and systolic pulmonary artery pressure significantly improved (both P < 0.001). We demonstrated beneficial effects of Mg2+ supplementation in patients with normal magnesium level. We suggest routine Mg2+ supplementation to all HF patients with low-to-normal Mg2+ levels and normal kidney function.