Any improvement in predicting whether a patient will develop heart disease is a win-win for patients and doctors. As more genetic data has become available, researchers are starting to see if predictions for heart disease can be improved by using the total genetic risk, also called the polygenic risk score. This kind of prediction uses information from the whole genome and is different from just looking for specific mutations that we know increase risk (e.g. BRCA2 mutations for breast cancer). It’s still unclear how much added value this kind of genetic prediction would give a patient. Recent research from Northwestern University puts these predictions under the microscope.
Using two ongoing studies of heart disease in the Netherlands and the US, these scientists tracked participants for up to 17 years and looked at the accuracy of two sets of predictions for whether a participant would develop heart disease. For both sets, they started with a baseline prediction, using things like age, cholesterol, and smoking history. In one set, they added in each person’s genetic information. The other set added in Coronary Artery Calcium (CAC) levels, which measures the plaque buildup in one’s arteries. CAC is found via CT scan and therefore isn’t routinely screened for; previous research also showed that CAC and genetic risk were similarly predictive. The research team found that adding CAC information to their prediction provided a statistically significant boost to their accuracy, while using genetic data did not.
This study doesn’t definitively conclude that genetic risk prediction is ineffective. The authors note that these genetic scores are still being refined. Genetic risk prediction might also be more accurate in younger people, who likely haven’t developed symptoms yet. A lot more research like this will be needed to figure out how much more genetic data we need and who will benefit the most.
Dr. Sadiya Khan is an assistant professor of Cardiology and Epidemiology at Northwestern Feinberg School of Medicine. Dr. Philip Greenland is a professor of Cardiology and Epidemiology at Northwestern Feinberg School of Medicine. Dr. Maryam Kavousi is an Associate Professor and Principal Investigator of Cardiometabolic Epidemiology at Erasmus University Medical Centre.
Managing Correspondent: Alex Yenkin
Press Articles: “Coronary Artery Calcium Score Beats Polygenic Risk Score at Heart Disease Risk Prediction,” Genome Web
“To Prevent Heart Attacks, Doctors Try a New Genetic Test,” The New York Times
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