Effect of statins on functional regulation of endothelial nitric oxide synthase (eNOS) in heart failure

INTERVENTION: Simvastatin 40 mg orally (or placebo) once a day (in the evening) will be administered for 6 weeks to each study participant. CONDITION: Heart failure with systolic dysfunction ; Circulatory System ; Heart failure PRIMARY OUTCOME: Changes in levels of superoxide, peroxynitrite, nitric oxide, tetrahydrobiopterin and brachial artery flow mediated dilatation and pulse contour analysis. Each outcome measure will be assessed at an initial visit, and then following randomisation and 6 weeks of treatment. SECONDARY OUTCOME: Changes in levels of markers of left ventricular (LV) dysfunction, adrenomedullin, N‐terminal prohormone brain natriuretic peptide (NT proBNP) and intermedin. Each outcome measure will be assessed at an initial visit, and then following randomisation and 6 weeks of treatment. INCLUSION CRITERIA: 1. Both males and females, over 18 years of age 2. Diagnosis of heart failure with an ejection fraction less than 35% determined by 2D echocardiography. Patients will be typically receiving maximal therapy for treatment of heart failure, including loop diuretics, angiotensin converting enzyme inhibitors or angiotensin receptor blockers, beta‐blockers and spironolactone. 3. Patients must also be able to give informed consent, and to attend for follow up appointments