We know from speaking to patients and their relatives that improving long-term outcomes after heart surgery is the most important area for future research. Coronary artery bypass is the most common heart operation performed. Usually a piece of the patient’s vein is used to bypass the blocked arteries in the heart. Problems with the veins used for the bypass are the most common cause of long-term problems after surgery. Usually this is caused by the cells in the wall of the vein multiplying and blocking the vein. It is thought that this is related to the speed at which blood flows through the veins.
In this project the speed of blood flow and its effects on the strain on the wall of the veins used for bypasses will be measured at the end of surgery to see if it is linked to later problems. Spare pieces of veins from bypass operations will be studied in the laboratory to see how blood flow and wall strain relates to vein blockage. We hope that this research can identify why veins used for bypass block over time.
As people age they become frailer. Some people develop frailty before others however. Frail patients are more likely to have problems after heart surgery. It is not always possible for doctors to work out who is frail and who is not.
In this research we will study samples of patients’ breath and blood to see if we can work out who is frail and who is not. For patients undergoing heart surgery we will study their heart tissue to see if that is also affected by frailty. By doing this work we hope to identify methods to identify frail people before surgery so that they can be looked after more carefully around the time of surgery to prevent complications.
For some people who develop severe problems with their heart or lungs the only way to keep them alive is to use a heart-lung machine to take over the job of their heart and lungs (extra-corporeal membrane oxygenation – ECMO). ECMO is becoming used much more commonly but many patients who start on ECMO unfortunately do not survive.
In people being treated with ECMO we will take samples of their breath and lung cells to see if we can develop new ways to monitor these patients. This research will help doctors work out if ECMO is going to work or not for an individual patient, help detect complications such as infection and see if people need closer monitoring after ECMO or not.