Most “risk calculators” ususally taken up to screen a patient’s chances of suffering a heart attack actually overestimate the likelihood of it, warn a group of researchers from Johns Hopkins University citing American Heart Association system too.
Four out of five widely used clinical calculators over-estimate risk, including the most recent one unveiled in 2013 by the American Heart Association and the American College of Cardiology, they said.
Physicians use standardized risk assessment systems, or algorithms, to decide whether someone needs care with daily aspirin and cholesterol-lowering drugs or just watchful waiting and follow-up exams.
These algorithms calculate heart attack probability using a combination of factors, such as gender, age, smoking history, cholesterol levels, blood pressure and diabetes among others.
“Our results reveal a lack of predictive accuracy in risk calculators and highlight an urgent need to re-examine and fine-tune our existing risk assessment techniques,” said senior investigator Michael J. Blaha from Johns Hopkins University.
For the study, the researchers followed 4,200 participants, aged between 50 and 74, for over 10 years.
The findings underscore the perils of over-reliance on standardised algorithms and highlight the importance of individualised risk assessment that includes additional variables, such as other medical conditions, family history of early heart disease, level of physical activity, its presence and amount of calcium buildup in the heart’s vessels, the researchers said.
The study appeared in the Annals of Internal Medicine.