Exploring Intramyocellular Magnesium Augmentation: Implications for Myocardial and Skeletal Muscle Metabolism in Individuals with Heart Failure with Preserved Ejection Fraction

Research summary

In patients with heart failure, serum hypomagnesaemia is common and attributed to increased renal magnesium (Mg2+) secretion and diuretic therapy. Serum hypomagnesemia is associated with increased heart failure presentations and hospitalisations in patients with heart failure with preserved ejection fraction (HFpEF). There is a poor correlation between serum Mg2+ (the compartment which can be measured) and intracellular Mg2+ concentrations9 (the compartment in which Mg2+ regulates cellular processes) with serum Mg2+ being a poor surrogate for total body Mg2+ content. Using 31 phosphate magnetic resonance spectroscopy (31P-MRS), intracellular Mg2+ can be assessed in vivo, without the need for a biopsy. This study is a single-centre, cohort comparison study. It aims to assess the relationship between intracellular Mg2+, and cardiac and skeletal muscle energetics and function. It also investigates the effect of increasing magnesium as a potential therapeutic target in HFpEF. Participants are separated into three groups; participants with HFpEF (n=45), age and BMI matched controls (n=20) and healthy controls (n=20). The study comprises two visits, where individuals will undergo a variety of investigations pre and post intravenous magnesium infusion. These include blood tests for serum Mg2+ and NT pro-BNP, a calf raise test, cardiac MRI and MRS, skeletal muscle MRS, and echocardiogram. Imaging and spectroscopy measurements are performed twice; at rest and stress (either with exercise or dobutamine). Study visit one will analyse the affects of magnesium pre and immediately post supplementation, and study visit two will repeat investigations 7-15 days after Mg2+ infusion to assess for delayed changes.

Principal Investigator

Prof Oliver Rider

Contact us

Email: cvm_nurses@cardiov.ox.ac.uk

IRAS number

331039