A person age 40 years or older has a 20 percent chance of developing congestive heart failure, according to a study in the November 5th rapid access issue of Circulation. The study authors also report that lifetime risk of developing heart failure is doubled for people with hypertension.

“Our data suggest differing degrees of importance for high blood pressure versus heart attack as risk factors for heart failure in women and men,” said lead author Donald M. Lloyd-Jones, M.D., a research associate with the Framingham Heart Study.

The lifetime risk for women without a history of myocardial infarction was 16.7 percent compared with 20 percent for all women. “This small difference in risk indicates that factors other than heart attack play a greater role in women’s risk for heart failure,” noted Lloyd-Jones. “Our data suggest that hypertension is the most important risk factor in women.”

In contrast, the lifetime risk for heart failure was reduced by almost half for men without a prior myocardial infarction (11 percent compared with 20 percent), a finding that indicates the importance of infarction as a risk factor in men.

The study highlights a significant link between hypertension and long-term risk for heart failure in both men and women. For 40-year-old women with systolic blood pressure below 140 mm Hg and diastolic pressure below 90 mm Hg, lifetime risk was 12 percent. For 40-year-old women with systolic pressure of 160 mm Hg or higher and diastolic pressure of 100 mm Hg or higher, the risk more than doubled to 28.9 percent.

For 40-year-old men with blood pressure less than 140/90 mm Hg, lifetime risk was 14.8 percent, whereas men with blood pressure of 160/100 mm Hg or greater had a risk of 27.9 percent.

Researchers have established lifetime risks for other diseases such as breast cancer. However, it’s been hard to pinpoint a true lifetime risk for heart failure because the most common symptoms, including dyspnea and peripheral edema, are associated with many diseases. As a result, studying lifetime risk in the general population requires researchers to “tease out” true heart failure from other conditions, according to Lloyd-Jones. “Framingham is a unique population where it is much easier to determine with confidence which people have congestive heart failure,” he said.

The researchers wanted to understand the lifetime risk of heart failure because hospitalizations for it have increased significantly in the last two decades. “In fact, congestive heart failure is now the leading cause of hospitalization for people over age 65,” said Lloyd-Jones.

The authors assert that lifetime risk is important because it helps to show the impact of a disease or syndrome on a population. Often, lifetime risk numbers help to draw attention to a condition and motivate people to change their behaviors or to see their doctors to determine their risk of diseases.

“These numbers are a clear message to doctors and patients that they should focus on lifestyle changes that can reduce risk for high blood pressure and heart attack. The information is also helpful for policymakers so they can better focus on congestive heart failure as a public epidemic and get the health resources needed to help modify behaviors and get treatment for what we know are predisposing factors,” said Lloyd-Jones.

He closed by adding that future U.S. studies should focus on minorities because the Framingham study population is predominately Caucasian.