The number of people 65 or older who are hospitalized for heart failure more than doubled in the past 27 years and is likely to keep climbing unless prevention measures are adopted quickly, U.S. researchers said on Sunday.

The American Heart Association estimates the chronic but often deadly condition will cost $34.8 billion this year in the United States for direct and indirect treatment costs.

"Over the next decades, the number of U.S. adults age 65 and older will double to a projected 70 million, and more than one in five will be 65 or older by the year 2030," Dr. Longjian Liu of Drexel University in Philadelphia said in a statement.

"Because heart failure disproportionately affects the elderly, there is no doubt that the burden of heart failure will increase unless innovative strategies are implemented," said Liu, who presented his findings at a meeting of the American Heart Association in New Orleans.

Liu studied national hospital discharge data on more than 2.2 million patients 65 or older between 1980 and 2006 and compared it with census population data.

He found the number of patients 65 and older who were hospitalized for heart failure increased 131 percent to 807,082 in 2006, from 348,866 in 1980.

While hospitalization rates for stroke and coronary artery disease have fallen since the mid-1980s, hospitalization rates for heart failure have continued to climb, Liu's study found.

"The prevention and treatment of heart failure has become an urgent public health need with national implications," Liu said. "The key is to prevent risk factors for the disease."

An estimated 5.3 million Americans have heart failure, a chronic disease in which the heart gradually loses its ability to pump blood efficiently, leaving organs starved for oxygen.

Risk factors include high blood pressure, heart attack, stroke, diabetes, obesity and lifestyle factors such as smoking, lack of exercise and a diet rich in fatty foods.

Doctors typically treat heart failure with a combination of drugs, including ACE inhibitors or angiotensin receptor inhibitors, which dilate arteries and veins, making it easier for the heart to pump blood; beta blockers to slow the heart rate and control blood pressure, and diuretics to reduce swelling.

Sometimes pacemakers are used to keep both chambers of the heart pumping in sync.