It's called the silent killer, and in a report last year, U.S. and European officials warned of a coming international epidemic of high blood pressure that will compromise the health of one-and-a-half billion people by 2050 if nothing is done. As VOA's Jessica Berman reports, hypertension is insidious, as it can cause few if any symptoms. Yet if not treated, it can lead to heart disease, stroke and kidney failure.

Barry Davis is a cardiologist at the University of Texas Houston. He says one consequence of high blood pressure is heart failure, where the heart stops working after a long, slow decline.

One consequence of high blood pressure is heart failure, where the heart stops working after a long, slow decline

"It's a high mortality rate once you develop this heart failure," Davis says. "Over five years, it's on the order of 40 to 50 percent of people who get the heart failure are going to die over that period of time. So, it's a very serious disease."

Doctors usually prescribe drugs known as ACE inhibitors and calcium channel blockers to try to slow the progression of heart failure, but that is not a cure. The American Heart Association recommends that cardiologists also give their patients diuretics or water pills during the later stages of their disease to siphon off water that's accumulated in their bodies as a result of a failing heart.

Davis and colleagues wondered what effect diuretics would have if they were given to patients who were seriously ill with high blood pressure, before their hearts began to fail.

In a study of 42 thousand patients 55 years and older who were hospitalized across the U.S., researchers found that water pills alone performed as well or better than ACE inhibitors and calcium channel blockers in preventing the development of heart failure in high blood pressure patients.

Davis says there could be several reasons for the favorable results.

"The diuretic was very good at lowering the blood pressure compared to other agents. That may have some aspect to it," he says. "The other one is diuretics are known to reduce fluid, the volume that is in the body. And it would put less strain in the body, not only filling up but in pumping out."

Davis says he's received e-mails from the authors of two other studies who reported that their efforts to save heart failure patients with expensive heart drugs were not successful.

"They did mention specifically this study and said, 'Maybe it's time to look at whether diuretic should be tested once you have heart failure versus the other agents,''" Davis says. "So, that's something for us to think about."

The results of the study were published in the journal Circulation.