If you're one of the millions of Americans whose blood pressure is creeping above normal, take note: A new study suggests the blood-pressure-lowering drug Atacand may be able to delay the development of full-blown hypertension among people whose blood pressure is slightly high.

In a new study, taking the drug for two years appeared to prime the body to keep blood pressure in check, even when the person stopped the drug for another two years.

The strategy isn't ready for prime time yet. But if it pans out in future research, it promises a host of rewards, says researcher Stevo Julius, MD, ScD, an emeritus professor of cardiovascular medicine at the University of Michigan Medical Center in Ann Arbor.

That's because people with 'prehypertension' are on the verge of developing the real thing, with all its risks: heart attacks, strokes, hospitalization, even death. To avoid these consequences, doctors put people with hypertension on blood-pressure-lowering pills -- often for life.

"Having to take medication for hypertension is a life sentence and patients don't like it," Julius tells WebMD. "This [strategy] could at least give people a chance."

The study, which was presented here at the American College of Cardiology annual meeting, was simultaneously published online in The New England Journal of Medicine.

Atacand and Hypertension Risk

Prehypertension is defined as having systolic blood pressure (the top number in a blood pressure reading) of 120 mm Hg to 139 mm Hg or diastolic pressure (the bottom number) of 80 mm Hg to 89 mm Hg. A person's blood pressure is considered high if the systolic pressure is 140 or higher or the diastolic pressure is 90 or higher. Normal blood pressure is a systolic reading of less than 120 and a diastolic reading of less than 80.

For the study, the researchers studied 772 people who fell into the high end of prehypertension, with systolic blood pressure readings of 130-139 and a diastolic reading of 89 or lower or a systolic pressure of 139 or lower and a diastolic pressure of 85 to 89.

For two years, half the participants were given Atacand and the other half, a placebo. Then for the next two years, they all were given placebo. All the participants also got diet and exercise counseling throughout the four-year study.

During the first two years, people on Atacand were two-thirds less likely to develop high blood pressure.

During the second two-year period with all participants taking placebo, there was still a significant difference in high blood pressure rates between the two groups, although it wasn't as large. The participants who had originally been on Atacand were 16% less likely to develop high blood pressure than the original placebo group after four years.

The risk of side effects was low in both groups.

Postponing High Blood Pressure

"The bottom line," Julius says, "is that if you treat early, the drug is well-tolerated and you can postpone hypertension. Two years of treatment with Atacand gives you one year of extra protection."

That said, "the effect was moderate and we need to improve on it," he says.

James H. Stein, MD, co-chairman of the cardiology meeting and associate professor of medicine at the University of Wisconsin Medical School in Madison, agrees.

While Stein says he found the 16% difference in hypertension rates disappointing, "the hypothesis is still alive."

The problem may have been that treatment wasn't started early enough, he tells WebMD.

"It's wishful thinking that starting medication when a person already has a blood pressure reading in the 130s will allow them to later go off their medication without consequence," he says. "Maybe if we started a person on treatment when their reading was still in the 120s, hypertension could be better forestalled or prevented."

Julius agrees, and hopes he gets funding to perform such a study.

While only Atacand was tested in this trial, Julius says he suspects that other blood pressure drugs would also work.

The study, called the Trial of Preventing Hypertension or TROPHY study, was funded by AstraZeneca, which makes Atacand. AstraZeneca is a WebMD sponsor.