Clinical Advisory: NHLBI Issues New Clinical Advisory on Systolic Blood Pressure
National Heart, Lung, and Blood Institute (NHLBI)
4 May 2000
May is National High Blood Pressure Education Month. It also is the start of a major campaign to increase awareness of the dangers of high systolic blood pressure, also known as systolic hypertension. The campaign is being undertaken by the National Heart, Lung, and Blood Institute (NHLBI) and the National High Blood Pressure Education Program (NHBPEP), which it coordinates. The NHLBI is part of the National Institutes of Health.
The cornerstone of the campaign is the release by the NHLBI and the NHBPEP of a clinical advisory recommending that systolic blood pressure be emphasized in the diagnosis and treatment of hypertension in middle-aged and older adults. The clinical advisory appears in this month's issue of Hypertension: Journal of the American Heart Association.
The campaign also includes the launch this month of a new high blood pressure Web site, with separate gateways for the public, health professionals, and community organizations.
"Systolic hypertension is a major health threat, especially for older Americans," said NHLBI Director Dr. Claude Lenfant. "While it cannot be cured, systolic hypertension can be treated and its complications prevented.
"Americans may have heard that diastolic blood pressure counts more," Lenfant continued. "That may be true for younger people. But we now know that, as people get older, systolic blood pressure becomes more important. May is National High Blood Pressure Education Month, and that's the perfect time to begin to sound the alarm-don't ignore your systolic. If you're middle aged or older, it's a better blood pressure indicator than diastolic of your risk of heart disease and stroke."
Dr. Daniel W. Jones, American Heart Association Representative to the NHBPEP Coordinating Committee and Director, Division of Hypertension, University of Mississippi Medical Center in Jackson, said, "Control of systolic blood pressure is important. This is a crucial message for health care providers, patients, and their families. For many years, the importance of lowering systolic blood pressure to less than 140 mm Hg has been overlooked and under-emphasized. This new NHBPEP advisory points out the overwhelming evidence that lowering systolic blood pressure can save lives."
For older Americans, the new message updates a clinical practice recommendation in the NHBPEP's 1997 guidelines, the Sixth Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure. Those guidelines note the importance of systolic blood pressure to cardiovascular risk. They also recommend using both systolic and diastolic blood pressures for diagnosis and treatment at all ages.
Since the guidelines were released, however, evidence has emerged that systolic blood pressure is the key determinant for assessing the presence and severity of high blood pressure for middle-aged and older adults. For example, findings from NHLBI's long-term Framingham Heart Study showed that systolic blood pressure alone correctly identified 91 percent of those who may need antihypertensive therapy, while diastolic blood pressure alone correctly identified only 22 percent of them. Among those over age 60, systolic blood pressure alone was even better able than diastolic pressure alone to correctly classify blood pressure. The study involved nearly 5,000 persons.
High blood pressure, or hypertension, is a serious condition that affects 50 million Americans-one in four adults. High blood pressure increases the risk of heart disease and stroke, the first- and third-leading causes of death among Americans. It also can lead to other conditions, such as congestive heart failure, kidney damage, dementia, and blindness.
Blood pressure is typically recorded as two numbers-the systolic pressure (as the heart beats) over the diastolic pressure (as the heart relaxes between beats). In the past, many physicians relied on diastolic blood pressure to diagnose hypertension. But research has found that diastolic blood pressure rises until about age 55 and then declines, while systolic blood pressure increases steadily with age.
For many older Americans, only the systolic blood pressure is high, a condition known as "isolated systolic hypertension," or ISH (systolic at or above 140 mm Hg and diastolic under 90 mm Hg). In fact, for older Americans, ISH is the most common form of high blood pressure. Sixty-five percent of all hypertensives over age 60 have ISH.
Unfortunately, according to the advisory, that is the same group that has the poorest hypertension control rate. This is "primarily as a result of inadequate systolic blood pressure control," the advisory notes.
For example, in hypertensives over age 70, only 25 percent of African Americans and only 18 percent of white Americans have their blood pressure under control to below 140/90 mm Hg.
The advisory emphasizes that research, including results from clinical trials, have proved that controlling ISH significantly reduces heart attack, heart failure, and stroke. The advisory recommends reducing systolic blood pressure to less than 140 mm Hg.
The advisory also agrees with current NHBPEP guidelines that recommend diuretics as a first-line treatment for ISH and the need to individualize treatment.
Other recommendations in the new advisory are:
- Blood pressure at all ages should be kept at below 140/90.
- Treatment for hypertension must begin early to prevent organ damage-whatever the patient's age.
- In hypertensives with diabetes, blood pressure should be kept below 130/85; and, in those with renal failure or heart failure, at the lowest level tolerated.
- Blood pressure should be reduced carefully in elderly persons with longstanding severe systolic hypertension; for resistant patients, blood pressure goals may take longer to reach.
The new national education campaign will try to increase the control rates for systolic hypertension by increasing awareness of the problem among patients and their physicians. A key part of the effort is the new Web site on high blood pressure.
Reached through the NHLBI home page at www.nhlbi.nih.gov, the Web site has separate gateways with offerings tailored for the public, physicians and other health professionals, and community organizations.
For instance, older Americans and others can find easy-to-understand information about high blood pressure, basic tips on how to control their high blood pressure, suggested questions to ask their doctor, and heart healthy recipes. They also can learn about the effects of uncontrolled high blood pressure on the heart, blood vessels, brain, and other organs.
Physicians can find such materials as the latest clinical practice guidelines and patient education resources, including ways to work with patients to increase treatment compliance.
Community organizations will find a resource kit to help them undertake local events in May and throughout the year to raise awareness of the importance of systolic blood pressure.
"Americans don't have to put their health at risk from uncontrolled systolic hypertension," said NHBPEP Coordinator Dr. Ed Roccella. "We now know how important systolic blood pressure is, and we also appreciate the clear benefits of controlling it. May is a season of new beginnings, and we hope Americans will hear this message and take action for a healthier life."
For an interview about the advisory or the new education campaign, contact the NHLBI Communications Office at (301) 496-4236. For an American Heart Association comment, call Carole Bullock at the News Media Relations Office at (214) 706-1279.
The new high blood pressure Web site and NHLBI press releases and other materials can be found online at www.nhlbi.nih.gov.