Clinician Q & A: What are the latest approaches to managing high blood pressure?

Despite all we know about the adverse health consequences of hypertension, it remains underdiagnosed and inadequately managed in the United States.

Many of the estimated 65 million Americans with hypertension are not aware that they have the disease, and a significant portion of those who are known to have the problem do not have their blood pressure under adequate control.

Yet, improved diagnosis and control has the potential to yield huge benefits to society with regard to the prevention of cardiovascular disease, especially stroke.

What can be done to address this persistent problem?

Duke cardiologist Michael Blazing, MD, responds:

The obvious first step is to identify the millions of Americans who don’t know they have elevated blood pressure. Screening programs sponsored by employers, senior centers, health departments, civic groups, and religious organizations are a great way to make people aware of their blood pressure reading and reinforce the importance of periodic evaluation for hypertension.

The educational message should begin long before adulthood, however, and given the scope of the problem, the problem of hypertension should be a recurrent component of health education in our school systems.

Once identified, an affected individual must be encouraged to seek out a care provider to confirm the diagnosis -- and an elevated blood pressure reading taken in the mall is often not enough impetus.

The benefits of treating hypertension are well established, and especially the benefits with regard to long-term stroke risk reduction.

Some of the reasons why people don’t seek out medical attention include the absence of symptoms, a lack of knowledge about the seriousness of uncontrolled hypertension, a fear of potential side effects associated with treatment, and limited access to care.

Some patients assume they will be faced with taking medications that they don’t want to take or can’t afford, and they don’t want to be bothered with the inconvenience of regular office visits.

Consider how many patients postpone seeing a physician even when they have alarming symptoms, like angina.

The JNC 7 Guidelines

Once the diagnosis is confirmed, the health care provider is then faced with managing the condition.

Here, there’s guidance from the most recent report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (JNC 7), published in 2003.

The JNC 7 report offers a classification system that includes changing the term “high-normal” blood pressure to “prehypertension” because the committee felt the former term did not adequately alert patients to their risk of becoming hypertensive.

The report provides a treatment algorithm that is also a component of a quick-reference office card that can be downloaded for free or purchased in a laminated form.

The JNC 7 also listed seven key points for clinicians:

1. After age 50, systolic blood pressure above 140 is a much more important risk factor for cardiovascular disease (CVD) than elevated diastolic pressure.
2. Most older patients will become hypertensive; even people who are normotensive at age 55 have a 90 percent lifetime risk of developing hypertension, according to data from the Framingham study.
3. Prehypertension begets hypertension, so think prevention. Lifestyle modification should be a part of treatment for all patients with hypertension or prehypertension.
4. Use thiazide diuretics, either alone or in combination with drugs from other classes, unless there are compelling reasons to do otherwise (such as renal disease and recent myocardial infarction).
   
   The results of ALLHAT (Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial), the largest hypertension trial of its kind with more than 42,000 participants aged 55 and older, provided strong scientific evidence for this recommendation.
5. Most patients will require two or more drugs to achieve goal blood pressure.
6. For patients with higher blood pressure (>20 mmHg systolic or 10 mmHg diastolic above goal pressure), start therapy with two agents, including a thiazide diuretic.
7. Work with the patient to build adherence. Build empathy, trust, and motivation by making sure the patient understands and agrees with the goals of therapy (by providing current and goal blood pressure readings verbally and in writing) and removing barriers to care whenever possible (such as the cost of medications and the complexity of care).

Another key point worth adding to the list is to treat the disease aggressively when the blood pressure readings indicate that medication is needed.

The old adage “start low and go slow” no longer seems prudent. The former prescribing pattern of sequential monotherapies -- trying one drug, then switching to a different drug when the first one doesn’t lower the blood pressure to goal -- has lost favor to the additive strategy (and, as noted in #5 above, patients are likely to need more than one drug).

Although the vast majority of patients have essential hypertension, it’s likely that they have several pathophysiologic mechanisms contributing to their disease and will benefit from a combination strategy that addresses these mechanisms.

This move to combination therapy requires clinicians to be aware that certain populations, such as the elderly and patients with diabetes or autonomic dysfunction, will require additional instruction and monitoring to minimize potential side effects of the medications.

The Beta-Blocker Controversy

The decision to convene the JNC 7 committee in 2003 to update the guidelines was based in part on the publication of many new hypertension observational studies and clinical trials since the release of the previous guidelines in 1997.

One important study not available in 2003 is the Anglo-Scandinavian Cardiac Outcomes Trial (ASCOT). The results from this long-term study of 19,000 European patients with hypertension were not available until late 2004 and have some experts in this country calling for updates to the current guidelines.

ASCOT, which compared the combination of a calcium channel blocker (CCB) and an angiotensin-converting enzyme (ACE) inhibitor to a beta-blocker and thiazide diuretic, was halted in December 2004 when an interim analysis found better outcomes for a wide range of cardiovascular events among patients receiving the CCB-ACE inhibitor combination.

Concerns about the use of beta-blockers as first-line treatments had been building for nearly a decade, and now meta-analyses of the use of beta-blockers in uncomplicated hypertension support the findings of ASCOT.

In June 2006 the United Kingdom’s National Institute for Health and Clinical Excellence (NICE) and the British Hypertension Society issued updated guidelines that relegate beta-blockers to a third- or fourth-line drug.

The guidelines also note that there is not an urgency to stop beta-blockers (particularly in someone whose blood pressure is well controlled) and that doing so abruptly can cause harm.

Moreover, patients with a compelling reason to take beta-blockers, such as angina or a previous MI, should certainly continue on the drug.

Adherence

Finally, health care professionals constantly deal with the issue of patient adherence -- and it’s especially difficult with a silent disease like hypertension.

Patients who come in symptom-free but need medications start having side effects, like frequent urination, and don’t want to continue with the drugs. Or the medication regimen is too complicated, or too costly. Or the patents aren’t motivated to make any lifestyle changes.

As noted in the JNC 7 guidelines, we need to work with our patients to maintain adherence. We can build empathy, trust, and motivation by making sure the patient understands and agrees with the goals of therapy -- by providing current and goal blood pressure readings verbally and in writing, for instance.

We must make sure they understand that hypertension is a chronic disease that won’t simply go away without some effort on their part to modify lifestyle factors that contribute to the problem and consistently to take medications that are returning their system toward their desired baseline values.

And we should try to remove barriers to care whenever possible, choosing less expensive alternative medications and less complex dosage schedules.

We hope that our efforts to manage this huge and costly medical problem will help reduce the morbidity and mortality caused by this silent disease.

Michael Blazing, MD, is director of the Adult Inpatient Cardiology Service at Duke University Hospital.