Lifetime risk for heart failure: One in five

DALLAS, Nov. 5 ? A person age 40 or older has a one-in-five chance of developing congestive heart failure, according to a study in today’s rapid access issue of Circulation: Journal of the American Heart Association.

The study authors also reported that lifetime risk of developing heart failure doubles for people who have high blood pressure.

Congestive heart failure (CHF) is a fatal disease more common among the elderly because of accumulated heart damage. It’s a syndrome in which elevated pressure inside the heart causes fluid to back up in the body. CHF can be caused by prior heart attack, long-standing high blood pressure, diabetes, or a tight or leaky heart valve.

“Our data suggest differing degrees of importance for high blood pressure versus heart attack as risk factors for heart failure in women and men,” says lead author Donald M. Lloyd-Jones, M.D. He is a research associate with the Framingham Heart Study, a long-standing study of cardiovascular risk factors funded by the National Heart, Lung, and Blood Institute.

The lifetime risk for women without a history of heart attack was one in six compared with one in five 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,” says Lloyd-Jones, who is also an instructor in medicine at Harvard Medical School in Boston. “Our data suggest that hypertension is the most important risk factor in women.”

In contrast, the lifetime risk for CHF was reduced by almost half for men without a prior heart attack (one in nine) compared with all men (one in five), which indicates the importance of heart attack for CHF risk in men.

The study highlights a significant link between high blood pressure and long-term risk for CHF in both men and women. For 40-year-old women with systolic blood pressure (the top number in a blood pressure reading) below 140 millimeters of mercury (mm Hg) and diastolic blood pressure (the lower number) below 90 mm Hg, lifetime risk for CHF 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 of CHF more than doubled to 28.9 percent.

For 40-year-old men with blood pressure less than 140/90 mm Hg, lifetime risk for CHF was 14.8 percent, while 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 congestive heart failure.

The most common symptoms of CHF, including shortness of breath and swollen ankles, are associated with many diseases. As a result, studying lifetime risk in the general population requires researchers to “tease out” true congestive heart failure from other conditions, Lloyd-Jones says. “Framingham is a unique population where it is much easier to determine with confidence which people have congestive heart failure,” he says.

The researchers followed more than 8,000 men and women for up to 25 years. The participants had no history of congestive heart failure at the start of the study, but 583 developed it during the study.

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

Lloyd-Jones says knowing lifetime risk is important because it helps show a disease’s or syndrome’s impact 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,” he says.

Future studies should focus on minorities because the Framingham study population is predominately Caucasians. It is especially important to look more at African Americans, who have increased rates of high blood pressure, says Lloyd-Jones.

Co-authors are Martin G. Larson, Sc.D.; Eric P. Leip, M.S.; Alexa Beiser, Ph.D.; Ralph B. D’Agostino, Ph.D.; William B. Kannel, M.D.; Joanne M. Murabito, M.D.; Ramachandran S. Vasan, M.D.; Emelia J. Benjamin, M.D.; and Daniel Levy, M.D.