To cut CHF, caregivers should get a handle on hypertension
To cut CHF, caregivers should get a handle on hypertension
Get aggressive; treat to goal, experts say
(Editor’s note: This is the first of a two-part series on managing hypertension. This month, we will examine the problems associated with hypertension and CHF. Next month, we’ll learn techniques and treatment options for dealing with hypertension and CHF. Our series will incorporate current medication options, alternative therapies, and suggestions on tailoring patient education programs to specific patient groups.)
As a health care professional, you know that hypertension is the most common reason for a patient to visit a doctor; it affects more than 50 million Americans; and it’s a major risk factor for stroke, kidney disease, and of course, heart disease, including CHF.
But you may not know that hypertension is largely to blame for the increase in CHF in recent years. Only about one-fourth of hypertensive patients have their blood pressure adequately controlled, and the problem will only get worse as improving life expectancy increases the number of elderly people in the United States.
Hypertension is a huge problem, and it’s specifically the caregiver’s responsibility to handle it. Getting blood pressure rates controlled to below 140/90 mm Hg is one of the few ways to make a positive impact on CHF, experts say.
But according to the Bethesda, MD-based National Heart, Lung and Blood Institute (NHLBI), which supplied those statistics, dramatic improvements in the treatment of hypertension seen from 1976 to 1991 have slowed and even decreased. During that period, the percentage of patients who were aware of their high blood pressure rose from 51% to 73%, and treatment increased from 31% to 55%, according to the National Health and Nutrition Examination Survey (NHANES).
The number of patients with high blood pressure controlled to below 140/90 mm Hg rose from 10% to 29%. The next round of NHANES, in 1994, found those numbers slipping: Only 68.4% were aware they had hypertension, 53.6% were being treated, and 27.4% were being controlled.1
A recent Mayo Clinic study found that downward trend continuing in a community that is socioeconomically prosperous with easy access to both primary and tertiary medical care. Out of 636 randomly selected Olmsted County, MN, residents studied, 53% had hypertension, 39% were unaware of that fact, and only 16% were being treated and controlled.2
"We are seeing a definite leveling off, even a deterioration, in our level of awareness, treatment, and control of hypertension, possibly because we aren’t paying enough attention to it," says Irene Meissner, MD, the researcher who led the study and a neurologist at the Mayo Clinic in Rochester, MN.
"This suggests that instead of making progress in combating the health threat posed by high blood pressure, we may actually be backsliding. People aren’t as aware as they should be, and control rates are quite low. This is happening despite solid clinical evidence that proper detection and treatment can dramatically reduce the number of deaths and disabilities caused by uncontrolled high blood pressure," she adds.
The trend is even worse when you consider that the NHANES surveys define adequate control as less than 140/90 mm Hg, while the current report from the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (JNC-VI) recommends 130/85. Also, the NHANES surveys don’t include people over age 75, the most rapidly growing segment of hypertensive patients, says hypertension expert Joel Neutel, MD.
Neutel is chief of clinical pharmacology and hypertension at the Veterans Affairs Medical Center in Long Beach, CA, and assistant clinical professor of medicine at the University of Cali-fornia, Irvine. When the over-75 age group is included, the control rate for U.S. hypertensive patients drops from 27% to 16%.
"Hypertension control in the United States is abysmal, and we are amongst the very best in the world," Neutel says. "We are only controlling 16% of hypertensive patients despite the fact that we have in excess of 100 drugs for treating this disease."
He points out that the CHF problem will only get worse since there are more hypertensive people in general, more older hypertensive people, and more survivors of heart attacks. "In order to make an impact on congestive heart failure, we have to take a much more preventive kind of approach," he says.
"Heart failure is a difficult disease to treat, and certainly, it’s not a disease we can cure. We can only try to control it. The essence of treating congestive heart failure is to protect patients from developing the actual disease process of which heart failure is a consequence. Blood pressure control is the most important thing we can do to protect people from developing heart failure," explains Neutel.
It’s not enough just to treat hypertension; you have to make sure the treatment is dropping the patient’s blood pressure to the goal level of 130/85 or better to prevent stroke, preserve renal function, and prevent or slow the progression of heart failure, Neutel says. "Treated but uncontrolled hypertensive patients remain at risk for cardiovascular disease.
"It’s not a golden bullet that if you treat hypertensive patients you’ll completely protect them from developing heart disease. The vast majority of hypertensive patients who develop cardiovascular disease have diastolic blood pressure somewhere between 90 and 104 and systolic blood pressure between 130 and 160. It’s not OK to accept inadequate control. We have to control them to the levels that we know are cardio-protective," he says.
Focus on systolic hypertension
Not only do physicians need to treat to goal, but they need to make sure they don’t ignore the systolic pressure, many experts say. Diastolic pressure accurately predicts heart disease and stroke risk in younger patients but doesn’t do as well with the elderly. There is overwhelming evidence to suggest that systolic hypertension is more important than diastolic in predicting cardiovascular disease, Neutel says.
"For all these years, we’ve really focused on diastolic blood pressure," he says. "Now that we have much more older patients who predominantly have systolic blood pressure, we’ve learned how important systolic is. If you bring systolic blood pressure down, that is associated with a dramatic impact on heart disease."
The JNC-VI guideline stresses this point, and recent studies underscore the risks of ignoring the systolic reading. New evidence from the NHLBI’s Framingham Heart Study3 found that systolic blood pressure — far more than diastolic blood pressure — identifies patients with hypertension, determines their blood pressure stage, and indicates the need for treatment.
Researchers found that systolic pressure alone correctly classified the JNC-VI blood pressure stage in about 96% of patients, compared to 68% using the diastolic pressure alone. In patients over age 60, the systolic pressure correctly classified 99% of patients, compared to 47% using diastolic alone.
Several studies presented at the American College of Cardiology’s 49th Annual Scientific Session held in March in Anaheim, CA, also focused on systolic pressure. One study from the University of California, Irvine examined the relative importance of the individual components of blood pressure in determining cardiovascular risk in more than 6,700 men and women in the Framingham Heart Study.
The researchers found that with age, the best predictors of cardiovascular risk shift from diastolic to systolic as well as to pulse pressures, perhaps because those are indicators of large vessel stiffness.4
A second related study5 presented at the conference found a more accurate way of using blood pressure to assess risk: tracking naturally occurring changes in diastolic and systolic blood pressure over a long period of time.
Researchers put two cohorts of men (15,561 men ages 20 to 82 and 6,246 men ages 42 to 53) into groups according to changes in their blood pressure, then kept track of deaths in each group for up to 17 years. Men with an increase in systolic and decrease in diastolic blood pressure had twice the risk of dying of cardiovascular disease than men whose blood pressure remained unchanged.
A third study6 found that most older patients with high blood pressure have higher than normal readings of systolic pressure but normal diastolic readings, challenging assumptions that high diastolic pressure is the more pervasive problem among people with high blood pressure.
Traditional focus is on diastolic data
The researchers analyzed blood pressure data on nearly 20,000 patients who took part in NHANES III. They found that 80% of participants over age 50 who had hypertension had systolic readings higher than 140 but had diastolic pressures below 90. Three-fourths of both treated and untreated hypertensive patients were more than 50 years old; only 26% were less than age 50. In both untreated and treated patients over age 50, there was a greater prevalence of systolic than diastolic hypertension.
Pablo LaPuerta, MD, one of the researchers on the NHANES study, says physicians have traditionally focused on diastolic blood pressure because the first clinical trials on hypertension recruited patients based on diastolic readings and because increasing systolic pressures had been thought to be a natural part of the aging process that couldn’t be controlled. But in the last four years, the clinical evidence has been mounting that systolic blood pressure shouldn’t be ignored.
"Systolic blood pressure increases with age so a lot of patients in their 70s and 80s have hypertension," says LaPuerta, who is a clinical assistant professor at the Robert Wood Johnson Medical School and director of outcomes research at the Bristol-Myers Squibb Pharmaceutical Research Institute in Princeton, NJ. "We found in this study that patients with isolated systolic hypertension are frequently very far from their target blood pressure goals, as much as 15 mm to 20 mm or more from their target goal. Most medications can’t lower systolic blood pressure to that degree."
The researchers concluded that selection and treatment biases favored diastolic blood pressure and that greater efforts must be made to identify and effectively monitor treatment regimens in high-risk patients.
One of the problems with treating that population is that many of them don’t even know they need help. A survey of 1,500 Americans over age 50, which was released in March by The National Council on Aging, found that nearly half did not know their own systolic and diastolic blood pressure. Sixty-nine percent said they had not discussed the physical consequences of high blood pressure with a doctor or nurse in the past year, and only 27% knew the importance of the systolic number as an indicator of high blood pressure. Forty-six percent incorrectly believed that stress is the main cause of high blood pressure.
Manage hypertension and CHF
It’s not an easy task to manage elderly patients with systolic hypertension, but those are exactly the people who need help, says Martin LeWinter, MD, a cardiologist with a special interest in CHF. LeWinter is professor of medicine and director of the cardiology unit at the University of Vermont College of Medicine and Fletcher Allen Health Care in Burlington. "There needs to be more emphasis on controlling blood pressure to prevent heart failure in elderly people with systolic hypertension."
LeWinter says management of heart failure is much easier when the blood pressure is down and that it’s fairly easy to achieve that goal for the 60% or so of CHF patients with decreased ejection fraction. "There are well-publicized guidelines for treating those patients, and those treatments — ACE inhibitors, diuretics, beta-blockers — will almost always control blood pressure also.
"But patients with normal ejection fraction are frequently the elderly patients with systolic hypertension who tend to get acutely ill with heart failure. With that group, there are no large studies available to guide therapy," LeWinter says.
"The importance of the group has been slow to get out there. People are somewhat reluctant to treat hypertension in older folks because they are more concerned about side effects. But you need to tailor the therapy to the older patient and find drugs they can tolerate," he adds.
References
1. National Institutes of Health/National Heart, Lung, and Blood Institute. The Sixth Report of the Joint National Committee on Prevention, Detection, Evaluation and Treatment of High Blood Pressure. NIH Publication No. 98-4080. Bethesda, MD; 1997.
2. Meissner I, et al. Detection and control of high blood pressure in the community: Do we need a wake-up call? Hypertension 1999; 34:466-471.
3. Lloyd-Jones DM, et al. Differential impact of systolic and diastolic blood pressure level on JNC-VI staging. Hypertension 1999; 34:381-385.
4. Franklin S, et al. The relation of blood pressure to coronary heart disease risk as a function of age: The Framingham Heart Study. J Am Coll Cardiol 2000; 35:291.
5. Benetos A, et al. Spontaneous changes in systolic and diastolic blood pressure can predict risk for cardiovascular mortality in men. J Am Coll Cardiol 2000; 35:334.
6. Franklin SS, et al. The need to focus on systolic hypertension: Analysis of NHANES III blood pressure data. J Am Coll Cardiol 2000; 35:334.
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