MONDAY, Nov. 5 (HealthDay News) -- American men and women -- even those with a favorable health history -- have a significant risk of developing cardiovascular disease in their lifetime, a new study finds.

Overall, U.S. adults have a more than 55 percent estimated risk of developing cardiovascular disease, the Chicago researchers said.

Even among those with no major risk factors, the chance of developing cardiovascular disease is more than 30 percent, although it appears to strike later, the researchers said.

The study was published online Nov. 5 in the Journal of the American Medical Associationto coincide with its presentation at the American Heart Association's annual meeting in Los Angeles.

"Lifetime risks for total [cardiovascular disease] were high regardless of index age, indicating that achieving older age free of total [cardiovascular disease] does not guarantee escape from remaining lifetime risk for total [cardiovascular disease]," the researchers said in a journal news release.

They added that the finding of a substantial lifetime cardiovascular disease risk even among individuals with an optimal risk factor profile highlights "the large public health burden and opportunities for prevention of total [cardiovascular disease]."

The findings are from an analysis of data collected from 1964 through 2008 in five studies funded by the U.S. National Heart, Lung, and Blood Institute. All the participants were initially free of cardiovascular disease.

In this study, the researchers looked at major cardiovascular risk factors such as high blood pressure, high cholesterol levels, diabetes and smoking, and calculated the participants' estimated overall lifetime risk (until age 95) for cardiovascular disease at ages 45, 55, 65 and 75.

Here are some of the highlights from the study, conducted by Dr. John Wilkins, of the Northwestern University Feinberg School of Medicine, in Chicago, and colleagues:

• At all age points, between 2 percent and 8 percent of participants had no major risk factors for cardiovascular disease, while more than 55 percent had at least one or two major risk factors.
• About one-third of the participants of all ages had a cardiovascular disease event, such as a heart attack, stroke or congestive heart failure, during the study period.
• At age 45, the estimated overall lifetime risk for cardiovascular disease was more than 60 percent for men and nearly 56 percent for women, the researchers found.
• Women had a much lower lifetime cardiovascular disease risk at all age points compared to men.
• At ages 55 and 65, the lifetime risk of cardiovascular disease was more than 50 percent for men and women who had high blood pressure or high total cholesterol but did not have diabetes and did not smoke.
• At age 55, men with optimal risk factor profiles -- normal blood pressure, normal cholesterol levels, no diabetes and non-smoking -- still had a lifetime cardiovascular disease risk of more than 40 percent, while women with optimal profiles had a nearly 30 percent risk.

Across all ages, people with heart-healthy profiles had a lower lifetime risk of cardiovascular disease than those with at least two major risk factors. For example, at age 45, people with optimal profiles lived up to 14 years longer free of cardiovascular disease than those with at least two major risk factors.

Dr. Stacey Rosen, vice president of Women's Health Clinical Services of North Shore-LIJ Health System in Great Neck, N.Y., said she prefers to view the research in a "glass is half-full" way.

Although the study "does conclude that the life-time risk for heart attack, heart failure and stroke remains high, despite optimal risk factor profiles, the data also demonstrates that those individuals with optimal risk factor profile at age 50 do have significant delay in the presentation of these forms of heart disease," she said.

The results highlight the importance of early identification and appropriate management of all cardiovascular risk factors, she added.

More information

The American Heart Association has more about cardiovascular disease.