One in Five Develops Heart Failure
High blood pressure, heart attacks increase risk
MONDAY, Nov. 4, 2002 (HealthDayNews) -- Americans have a one in five chance of developing heart failure after age 40, but the odds of getting the lethal disease are much greater for people with high blood pressure.
So says a new study, which followed more than 8,200 Massachusetts men and women between 1971 and 1996. It found the average man and woman had about a 20 percent risk of developing congestive heart failure through middle and late adulthood. For those with blood pressures at or above 160/100 millimeters of mercury, the lifetime risk was twice as great as for those whose pressure was at 140/90 mmHg or lower -- 29 percent versus 12 percent for women and 28 percent versus 15 percent for men.
Men, but not women, with a prior heart attack had twice the risk of heart failure as those without such a history.
"We want people to understand the risk that they face and use that [information] for prevention" of heart failure, says Dr. Donald Lloyd-Jones, a co-author of the study. Ways to avoid the disease include eating a low-salt diet, exercising regularly and not smoking, Lloyd-Jones says. He and his colleagues report their findings in tomorrow's online edition of Circulation.
Reducing the national systolic blood pressure -- the higher of the two numbers -- by 5 mm would lower rates of heart failure by at least 25 percent, experts say. Among patients with hypertension, a 10 mm drop in systolic pressure can cut the risk of heart failure in half. Normal blood pressure is considered to be below 130/85, while optimal is not more than 120/80.
Many experts have called heart failure an epidemic in this country. The disease affects about 4.8 million Americans and kills nearly 290,000 a year. Drugs such as diuretics that help the body shed water can provide short-term relief for heart failure patients, as can other drugs that make the heart's job easier. However, the disease has no cure and even patients who have heart transplants don't have a normal life expectancy.
Heart failure begins when the pump can't efficiently move blood to the kidneys, which in response retain salt and water. That scrambles the feedback loop between the two organs. Vessels then become too full and leak into the lungs, hampering their ability to shuttle oxygen into the blood.
Lloyd-Jones and his colleagues analyzed data from the Framingham Heart Study, an ongoing research project that has followed thousands of people since 1948. It now includes a third generation of men and women, bringing the total enrollment to about 14,000.
Between 1971 and 1996, there were 583 cases of congestive heart failure in the 8,229 participants included in the latest study. While having high blood pressure doubled the likelihood of the disease in both men and women, people with low pressure had nearly half the average risk.
Women who had normal blood pressure and no history of a heart attack had a one in nine chance of developing heart failure. For men without hypertension and no previous attack, the chances were one in six.
Lloyd-Jones, also of Harvard Medical School in Boston, says the Framingham results should apply to the rest of the country. However, for blacks the lifetime chances of developing heart failure would likely be greater than 20 percent because they are more prone to high blood pressure and diabetes, another risk factor for the condition, he explains.
"The relationship between high blood pressure and heart failure has been well recognized for many years, and the efforts to adequately control blood pressure have been promoted over many years without as much success as we would hope," says Dr. Jay Cohn, a heart failure expert at the University of Minnesota Medical School in Minneapolis.
However, Cohn, a founder of the Heart Failure Society of America, says many people with normal blood pressure also go on to develop the condition.
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