Researchers have said that the current practice of calculating a patient's risk on short term basis may give false information about his/her chances of having a heart attack or stroke.
A New Northwestern Medicine research revealed a young or middle-aged adult who is at low risk in the short term may be at very high risk in the long term - if he or she has just one or two risk factors such as higher than optimal cholesterol or blood pressure levels.
This is the first study to examine the lifetime risk of heart disease in white and black men and women.
Previous studies have been in whites and predominantly males. It's also the first study to look at the entire adult age spectrum.
The research also looked at the risk across multiple birth cohorts and found the effect of the risk factors remained consistent regardless of the decade in which a person was born.
Part of the Cardiovascular Lifetime Risk Pooling Project, the research tracks more than 250,000 participants from 18 different groups of people living in the community over a period of more than 50 years.
The patients' risk factors for cardiovascular disease-blood pressure, cholesterol levels, smoking status and diabetes status-were measured at ages 45, 55, 65 and 75 years for each participant.
"We are giving incomplete and misleading risk information if we only focus on the next 10 years of someone's life," said principal investigator Donald Lloyd-Jones, MD, chair and associate professor of preventive medicine at Northwestern University Feinberg School of Medicine and a physician at Northwestern Memorial Hospital.
"With even just one risk factor, the likelihood is very large that someone will develop a major cardiovascular event that will kill them or substantially diminish their quality of life or health," he said.
The risk-factor profile was considered optimal when a participant had a total cholesterol level of less than 180 milligrams per deciliter and untreated blood pressure of less than 120 over less than 80, was a non-smoker and did not have diabetes.
The new research on long-term risk may be important in estimating the future burden of cardiovascular disease in the general population, Lloyd-Jones noted.
The study found that men who are 45 years old and have all risk factors at optimal levels have a 1.4 percent risk of having a heart attack or stroke or other form of death from heart disease while having two or more risk factors hike the risk to 49.5 percent.
For 45-year-old women with all risk factors being optimal, the chance of having a heart attack or stroke in their lifetimes is 4.1 percent while having two or more risk factors boost it to 30.7 percent.
"Just even one small increase in risk, from all optimal risk factors to one that isn't optimal, like slightly elevated cholesterol or blood pressure, significantly bumps up a person's lifetime risk," Lloyd-Jones said.
Women have a higher risk than men for a stroke over their lifetimes but a lower risk for a heart attack.
"This study underscores the importance of lifestyle-particularly diet, exercise and smoking cessation-all the lifestyle patterns that are important in reducing the development of the risk factors in the first place," said Jarett Berry, MD, who worked on the study when he was at Northwestern's Feinberg School and is now assistant professor of medicine at University of Texas Southwestern Medical Center.
The study has been published in the New England Journal of Medicine.