New research will help personalize cardiac prevention therapies in the future

Assessing risk for future heart disease or stroke is a routine part of every Canadian’s annual physical, but research suggests that the assessment score substantially overestimates risk.

New recently published findings in the Journal of the American College of Cardiology show that recalibration of existing risk scores using contemporary population-level data can improve risk estimates, more precisely determining whether a patient should be prescribed cholesterol-lowering statins.

“When the risk score predicts high future risk, we might be inclined to believe the benefit of starting a prevention medication is greater than it really is,” says Dr. Dennis Ko, senior author of the study, a cardiologist and senior scientist in the Schulich Heart Program at Sunnybrook Health Sciences Centre, and a senior scientist at ICES. “Many of our medications are beneficial for most patients, but come with costs, including the burden of pill taking, bloodwork, or side effects.”

The research team set out to correct overestimations in existing risk scores by recalibrating them using up-to-date cardiovascular disease incidence rates and risk factor prevalence levels in Ontario. They focused on two scores known to overestimate risk, one of them being the Framingham Risk Score (FRS), which is recommended to be used in Canada.

“The risk for a heart attack for the average individual alive today differs from an individual who may have lived several decades ago when these initial risk scores were developed,” says Dr. Maneesh Sud, lead author of the study and a cardiologist and PhD student in the Schulich Heart Program at Sunnybrook. “By calibrating the scores with current population data, we can reflect contemporary improvements in lifestyle factors such as diet, physical activity, lower rates of smoking and exposure to second-hand smoke, as well as better treatment of dyslipidemia, high blood pressure and diabetes. We can also better reflect the diversity of our population.”

After recalibrating the Framingham Risk Score, overestimation was reduced. The authors say when overestimation was reduced it had the potential to improve treatment decisions.

“More accurate scores meant fewer individuals need to be treated with statin medications in order to prevent one heart attack or stroke at five years,” says Dr. Sud. “However, recalibration of another scoring system did not improve overestimation.”

While the results will ultimately inform personalized decision making, there remains room to improve. The authors’ next step is to utilize the data they now have to build new and more accurate prediction models.

“We need to have better tools to treat patients when medications are needed, so that patients feel confident and well informed about their decision to start or not start a preventative medication,'' says Dr. Ko. “This will ensure patients are on the right therapy when they need it most.”

Media Contact:

Samantha Sexton
Communications Advisor
Sunnybrook Health Sciences Centre
samantha.sexton@sunnybrook.ca