Blood Pressure Drugs Keep Hypertension in Check
Patients using angiotensin receptor blocker postponed progression to hypertension, study finds
TUESDAY, March 14, 2006 (HealthDay News) -- Using drugs to treat prehypertension reduced the risk of developing full-blown hypertension, a new study finds.
Although using pharmaceuticals may one day offer increased hope for millions of people with high blood pressure, the authors of this study stress that this treatment is not yet ready for prime time.
"It only shows the feasibility of this approach," said study author Dr. Stevo Julius, active emeritus professor of medicine and physiology at the University of Michigan, in Ann Arbor. "It is safe and it can be done, but it is a relatively small study and the time frame on the drug was only two years and generally, in our field, we want to see longer-term studies, so we're not ready to recommend this as a massive way of treating patients."
The study is nevertheless a breakthrough in the field. "We are the first, and we truly had to work for that," Julius said. "It's quite unusual. People are not given to adventures in our field. We've done it and we are very pleased."
The study was presented Tuesday at the American College of Cardiology annual meeting in Atlanta, and will also appear in the April 20 issue of the New England Journal of Medicine.
People who have blood pressure higher than normal but less than what is considered hypertension have prehypertension. Like people with hypertension, people with prehypertension are at an elevated risk for heart disease. They will also typically go on to develop hypertension.
Prehypertension is defined as systolic blood pressure in the range of 120 to 139 mm/Hg and diastolic blood pressure of 80 to 89 mm/Hg. Some 70 million Americans have the condition.
But the division is an artificial one. "High blood pressure is a continuum," said Dr. Gary Orin, a board-certified internist and nephrologist at Lenox Hill Hospital in New York City. "You can't really draw a line. There's no magic number."
Over the years, hypertension has been defined at lower and lower numbers, he noted.
Whatever the number, current guidelines recommend lifestyle modifications, rather than pharmaceuticals, for the management of prehypertension. But given the increasing prevalence of prehypertension, this approach does not seem to be working.
For this study, about 800 participants were randomized to receive Atacand (candesartan cilexetil) or a placebo for two years. Atacand is an angiotensin receptor blocker (ARB), which relaxes the blood vessels and widens them. This lowers blood pressure.
The study was sponsored by AstraZeneca, which makes Atacand.
All participants had prehypertension, defined here either as systolic pressure of 130 to 139 mm Hg and diastolic pressure of 89 mm/Hg and lower, or a systolic pressure of 139mm/Hg or lower and diastolic pressure of 85 to 89 mm/Hg. The mean age of the participants was 48.5 years; 59.6 percent were men.
After two years, 154 participants taking a placebo and 53 taking Atacand developed hypertension. This means that those in the intervention group had a 66.3 percent lower risk of developing hypertension. The authors calculated that four participants with prehypertension needed to be treated for two years to prevent one case of hypertension.
After four years (or two years after participants stopped taking the drug), hypertension had developed in 240 people in the placebo group and 208 in the Atacand group. In other words, people taking Atacand had a 15.6 percent lower risk of developing hypertension.
The drug also appeared safe, with serious adverse events reported in 3.5 percent of those taking Atacand and 5.9 percent of those receiving a placebo.
"We are trying to find out whether this is safe in the long term," Julius said. "It looks good. In two years of treatment, there was no difference in side effects between the placebo and the other group, and there was considerable postponement of hypertension."
Another heartening aspect of the trial, an accompanying editorial pointed out, is that Atacand seemed to affect the actual progression of the disease, rather than just mask symptoms.
Before this becomes practice, however, more studies need to be done.
"We are trying to find patients at the highest risk and treat them for a longer period of time," Julius said.
For more on hypertension, visit the American Heart Association.