Current heart health guidelines suggest that healthy adults whose blood pressure is higher than normal but below a level that would pose a significant risk for cardiovascular disease are not the best candidates for drug therapy. Instead, these patients exist in limbo with "pre-high blood pressure" or "pre-hypertension," which is a blood pressure between 120/80 and 140/90.
While current guidelines suggest that the 70 million adults in this category are not candidates for drug therapy, a new study published Thursday in the journal the Lancet says that such medical treatment to manage blood pressure could serve these patients better.
Researchers from Italy argued that pre-hypertensive patients should be treated aggressively to reduce their systolic (the top number) blood pressure -- the force that the blood exerts on arteries and which is measured in millimeters of mercury -- to under 130 to avoid full-blown hypertension and potential cardiac problems.
"There is a direct relationship between the usual levels of blood pressure and the risk of major cardiovascular events, according to epidemiological studies," said Dr. Paolo Verdecchia, from the Hospital S. Maria della Misericordia and ANMO Research Centre in Italy and lead author of the study, which was funded by the pharmaceutical companies Boehringer-Ingelheim, Sanofi-Aventis and Pfizer. "Even a small further reduction in blood pressure predicts a lower risk of major events" such as heart attack and stroke.
Verdecchia and his team studied 1,111 patients over age 55 who were randomly assigned to keep a target blood pressure of less than 140 or 130. At the end of two years, the more tightly controlled group was found to have less chance of abnormally thickened heart muscles, which indicates impending heart problems and fewer hospitalizations for heart-related issues.
No one in the study had diabetes, a major contributing factor for high blood pressure and heart disease.
Heart experts said the study supports a common sense approach to managing blood pressure, which is to keep it as low as possible.
"[Perhaps] our targets are too conservative in the treatment of patients with higher blood pressure," said Dr. Randall Zusman, director of the hypertension program at the Massachusetts General Hospital Heart Center. "This study goes a long way toward suggesting that we should be more aggressive."
But aggressively treating pre-hypertension with drugs to lower blood pressure, such as ACE inhibitors and beta blockers, has not been the norm in the past as it has been for treating outright hypertension.
"We really don't have any evidence that if we treat patients in that [middle] range we're going to prevent cardiovascular mortality," said Dr. Olugbenga Ogedegbe, associate professor of medicine director of The Center for Healthful Behavior Change at NYU Langone Medical Center. "It's not just to prevent heart attacks and strokes. We want to prevent deaths, but there are no studies on this."
In addition, pre-hypertension often occurs with a host of other issues that typically require medication such as diabetes, high cholesterol and obesity. A family history of hypertension and heart disease can also complicate treatment.
Doctors often have to choose which conditions to treat more or less aggressively so as not to overwhelm patients with drugs.
"There is the inertia of pushing the dose and the number of drugs to reach a target in a patient population that is initially asymptomatic or also taking many other drugs," Zusman said. "You want to maximize benefits and minimize adverse effects."
Zussman noted the importance of introducing exercise into the daily routine as well as controlling diet, weight and stress to help manage pre-hypertension without medication.
The study did not take into account the effect of many types of medicines or co-morbid diseases on pre-hypertensive patients because the participants were relatively healthy, non-diabetic adults. Nor did the researchers control the type of medications used.
Dr. Howard Weintraub, clinical director of the Center for the Prevention of Cardiovascular Disease at NYU Langone Medical Center, also pointed out that the lack of diversity in study participants leaves gaps in data on tight blood pressure control in high risk populations such as African Americans, who, at any level of blood pressure, are at greater risk of cardiovascular disease.
Verdecchia said such gaps may all be points at which research on pre-hypertensive patients could continue.
But he added that about 80 percent of the sample population achieved their target. The overall effect was a significant reduction in the rate of left ventricle hypertrophy, the heart muscle thickening that indicates high blood pressure, in the group that was tightly controlled to reduce their systolic blood pressure to below 130.
Also significant was a reduction in the prevalence of several secondary indicators of high blood pressure, including heart attack, heart failure, angina, arrhythmias and kidney failure.
While Verdecchia's data do not have the strength to justify altering guidelines on managing blood pressure developed by organizations such as the National Institutes of Health and American Heart Association, they do give physicians leeway to treat those at risk for hypertension as aggressively as they and their patient wish.
And even if they are in conjunction with medication, first line treatment will remain suggestions live more healthfully.
"If a patient comes in with pre-hypertension, I'd assess them for other cardiovascularities -- cholesterol, weight, diabetes, family history -- and encourage them to engage in therapeutic lifestyle change," Ogedegbe said. "But [this study] goes to show that treating patients regardless of their blood pressure level can prevent other cardiovascular risk factors."