Early detection of coronary artery disease by polygenic risk scoring (EDCAD-PMS): an opportunity to start secondary prevention without a coronary event
Principal researchers: Professor Tom Marwick, Professor Peter Meikle, Professor Michael Inouye and Associate Professor Melinda Carrington
Associate researchers: Dr Kunal Verma and Dr Prasanna Venkataraman, Dr Yusuke Sata and Dr Nitesh Nerlekar
Research team: Ms Asmita Dalal, Ms Sally Kay and Ms Lilly Zhu
Coronary artery disease (CAD) is a major cause of sickness and death in Australia. The current approach to preventing its consequences (heart attacks and angina) is to determine the level of risk based on blood pressure, diabetes etc., and start treatment in those at high risk. Statins are a class of drugs often prescribed by doctors to help lower cholesterol levels in the blood. By lowering the levels, they help prevent heart attacks and stroke.
Traditional risk factors only allow us to identify some people at risk, and therefore we are missing some of those who need early treatment to prevent a heart attack/stroke and potentially unnecessarily treating others. We therefore need better ways of identifying those who would benefit from treatment. We are trying to improve the prediction process to better identify those who may benefit from treatment.
Our genes contain the instructions for how our body works, and this can be thought of as a book. While each of us have a very similar book of instructions or set of genes, there are some differences between us that can affect the way in which our body works. Sometimes these changes mean some of us are more likely to develop certain types of diseases. These differences between individuals are referred to as genetic variants. For CAD there are thought to be many genetic changes that may be associated with increased risk of having a serious cardiac event. Measurement of the many genetic changes associated with a disease, is called a polygenetic risk score (PRS). We would like to examine participant’s genes to see if the genetic changes that are associated with CAD are also associated with coronary calcium and who are most likely to benefit from medication such as statins.
To perform the genetic risk score, we would like to collect a blood sample for genetic analysis, as well as ask the participant to have a standard “CAT” scan (CT) to identify if they have coronary calcification (a build up of calcium in the heart’s arteries). If calcification is present, we will also the participant to undertake a CT coronary angiogram (which involves injection of a contrast dye). We are trying to find out if there is a relationship between genetic changes and the presence coronary artery disease identified on CT.
Our main aims for this study are to identify whether:
- PRS can predict the presence of coronary calcium.
- Knowledge of the PRS result is better or worse than knowledge of the CT scan result in guiding people to reduce their risk (by changing lifestyle and taking medications).
This research is being conducted at the Baker Heart and Diabetes Institute, together with the Australian Genomic Research Facility.