Controlling Systolic Blood Pressure Early Prevents Heart Disease in Elderly, Reports University of Pittsburgh Researcher
HONOLULU, April 25, 2002 — Hypertensive elderly individuals who begin blood pressure therapy before signs of heart disease appear may completely avoid the associated cardiovascular problems, according to a researcher from the University of Pittsburgh Graduate School of Public Health (GSPH) who presented these findings at the American Heart Association's 42nd Annual Conference on Cardiovascular Disease and Epidemiology Prevention.
"We found that elderly individuals with untreated systolic hypertension are three times more likely to experience adverse cardiovascular events like heart attack, angina, stroke or heart failure than are elderly individuals with normal blood pressure," said presenter Kim Sutton-Tyrrell, Ph.D., associate professor of epidemiology at GSPH.
"However, hypertensive study participants who underwent treatment for their high blood pressure greatly reduced their risk of adverse cardiovascular events, particularly if they were still free of detectable disease when they initiated treatment."
The findings are based on an analysis of the Pittsburgh cohort of the Systolic Hypertension in the Elderly Program (SHEP), a national clinical trial that was the first to show the effectiveness of treating systolic hypertension.
Approximately 30 percent of people age 80 and above have systolic hypertension, a type of high blood pressure that is a result of atherosclerosis (stiff vessels or "hardening of the arteries"). Systolic hypertension is reflected in a blood pressure reading that has a high top (systolic) number and a normal low (diastolic) number.
The SHEP trial lasted 4.5 years, after which participants who had been taking placebo were encouraged to see their doctors and begin medication therapy. Some did and some did not. Likewise, some participants in the medication group voluntarily discontinued therapy after the trial ended.
University of Pittsburgh researchers continued to follow all of the Pittsburgh SHEP participants for 12 years to determine the number of cardiovascular (CV) events occurring in each group, regardless of whether or not the participants had continued, stopped or started medication. Only 60 percent of the participants originally taking the medication remained on the therapy. CV events include death, heart attack, stroke, angina, congestive heart failure or vascular surgery.
The Pittsburgh arm of the study consisted of 134 participants taking hydrochlorothiazide, a diuretic commonly prescribed for systolic hypertension (the "active" group), and 134 taking a placebo. Participants in both groups had an average systolic blood pressure of 171 mmHg and an average age of 74 years at study entry. A comparison group (controls) of 187 similarly aged individuals had an average systolic blood pressure of 127 mmHg, which is considered normal.
After 11 years, the participants who had originally been taking a placebo had three times the number of CV events than the controls, but participants originally in the active group had only 1.6 times the number.
Among participants who were free of cardiovascular disease at study entry, 68 percent of those originally on placebo experienced CV events, but those who took the medication had outcomes similar to those of the control group (29 percent vs. 28 percent).
Even though only 60 percent of the original active group remained on the medication, that group had significantly fewer cardiovascular events 12 years later, indicating that even 4.5 years of therapy in one's 70s can have protective effects a decade or more later.
"All too often, physicians focus on diastolic blood pressure, and isolated systolic hypertension is not treated, particularly when patients are older," said Dr. Sutton-Tyrrell. "This study demonstrates that even for individuals who are at an advanced age, treating systolic hypertension is vital to avoiding deadly cardiovascular diseases that can result."
Established in 1948, the GSPH at the University of Pittsburgh is world-renowned for contributions that have influenced public health practices and medical care for millions of people. It is the only fully accredited school of public health in the Commonwealth of Pennsylvania and one of the top-ranked schools of public health in the United States.