Sometimes blood tests are performed in patients with heart valve disease. If you have symptoms such as shortness of breath or chest pain/discomfort, your healthcare team may wish to check your blood count to ensure you are not anaemic (low red cell count). Often your baseline kidney, liver and thyroid function is also checked. Before invasive coronary angiography it is usual to check the blood count, kidney function and also that the blood can clot normally. The kidney function is also checked before CT scans requiring dye injection and sometimes also before a magnetic resonance scan if gadolinium is going to be injected as a ‘dye’.
Sometimes a specialised blood test known as a Brain Natriuretic Peptide (BNP) is also used to check whether the heart valve disease is causing strain on the heart. This can help unpick whether the heart is the main cause in people with multiple possible reasons for being breathless (e.g. lung disease or obesity). Occasionally a very high BNP level can help guide the decision to recommend surgery in severe aortic stenosis even if you have no symptoms.