Effect of Sildenafil on PA Pressure during exercise and hypoxia in CHF
The effects of sildenafil on pulmonary vascular haemodynamics at rest and during exercise with and without reduced inspired oxygen concentration in patients with chronic heart failure.
Hull & East Yorkshire Hospitals NHS Trust
We will apply
Heart failure is common and serious. High pressures in the artery in the lung (the pulmonary artery) are associated with more breathlessness, a poorer quality of life and poorer survival. Pressures are thought to increase during exercise and when the oxygen concentration in the air is reduced. However, little research exists on how pressures change with such stresses or whether they can be prevented by treatment. Sildenafil (Viagra) improves erectile function but also reduces pulmonary artery pressures, measured by heart catheters, at rest and exercise under normal oxygen conditions. We will investigate the effects of sildenafil during lower oxygen concentrations (15% oxygen, similar to oxygen concentrations in the cabins of airliners) at rest and during low-level exercise. We will enrol patients with heart failure, defined as a clinical diagnosis supported by appropriate tests, who have a measurable leak across one of the heart valves (the tricuspid), which is very common in this population, that allows pulmonary artery pressure to be calculated. Patients will be familiarised with study procedures. Patients will be randomised, double-blind, either to sildenafil (two doses of 20mg) or placebo to investigate their effects on pulmonary artery pressure during mild exercise breathing air or 15% oxygen. Patients will receive these alternative ??treatments?Â on separate days. This study will provide new information that may improve patient-care. The study may also provide a new non-invasive model for investigating treatments directed at pulmonary artery pressures that will allow faster development of new treatments and be more acceptable to patients.
West of Scotland REC 1
Date of REC Opinion
8 Apr 2009
Further Information Favourable Opinion