BP control: Why are we not making progress?

Plenty of clinical trial data support aggressive treatment, yet physicians remain cautious and patients confused.

Despite all the evidence-based data from hypertension trials over the past two years, little progress has been made toward controlling blood pressure in the United States. According to NHANES data, blood pressure control was 10% within the survey population in 1976; by 2000, that percentage had increased to only 34%.

If we look at the recent studies that have been done — ALLHAT, INVEST, VALUE, ASCOT, to name just a few — it is apparent that blood pressure can be controlled in the majority of people. For example, blood pressure control was about 72% in the INVEST trial. In these trials blood pressure control required use of a regimen, with more than one drug applied in pharmacologically sound combinations. Preferably the drugs used in combination have mechanistic differences to help to achieve control in the majority of patients. With all we now know, we should be making more progress. Why is this not happening?

Have we confused physicians and patients?

The optimal level for blood pressure still has not been firmly established. Early during my career 160 mm Hg systolic was considered the threshold for drug management. Then this changed to 140 mm Hg, which is currently viewed by most physicians and patients as the level for hypertension. Does this mean that patients with a blood pressure of 139 mm Hg do not have a disease related to the hydraulic effects of blood flowing within the cardiovascular system? Certainly many patients have this interpretation.

Carl J. Pepine

Then we introduced lower blood pressure goals for “special populations” defined as subgroups at higher risk (diabetes, renal insufficiency). Could this be interpreted to mean that most of the people with hypertension are not at high risk?

More recently JNC 7 introduced the term “prehypertension,” and it is easy to understand that most patients and many physicians are confused. We have to dispel the notion that a patient whose blood pressure is 139 mm Hg on one day and 140 mm Hg on the next day suddenly develops a disease. We need to move toward the same message now used for lipid management: hypercholesterolemia is out, optimal LDL is preferred.

But what is optimal blood pressure?

Are physicians too cautious?

Even with trial results like those from the INVEST, in usual clinical practice blood pressure is still not aggressively treated in most patients. Why is this? Does it have to do with the education of physicians? To some extent, this may be true. If you ask physicians to state the recommended blood pressure goal, many cannot do so. Most do not use drug combinations, and most do not escalate doses when blood pressure is in the 140 systolic range.

ALLHAT results clearly confused many people. The trial chose drug combinations that were neither pharmacologically sound nor useful in practice. They have continued to perpetuate the notion that beta-blockers and diuretics must be good. Many patients cannot be controlled to the lower targets and they ignored the issue of new-onset diabetes.

Physicians continue to be very concerned about reducing blood pressure levels too low. Aside from orthostatic symptoms, there are data from population studies and treatment trials to suggest that very low diastolic blood pressure may be deleterious. So this concern seems well justified.

Do patients resist medication?

Patients are also very cautious. Drugs were provided free to patients in the trials noted above, yet about a third of those treated were still hypertensive by the conclusion of the trial. Was this because patients are resistant to taking medication, even if it is free, because they think they are taking too many drugs?

Many patients are reluctant to take their blood pressure medication daily when they don’t feel sick. Patients need to be made aware that the disease remains silent until they have their first MI or stroke or die.

Are some patients simply more difficult to treat?

Of course, there are groups of patients who are harder to treat. We find that hypertension is difficult to control in blacks, yet control is relatively easy in Hispanics. When I tell that story in Europe, I am told that that is just the opposite in Spain, where controlling blood pressure is difficult.

We don’t know why that is so, but my guess is that the admixture of Native Americans into our Hispanic population in the United States could be the answer.

Treating blood pressure in patients with diabetes, metabolic syndrome and obesity is also more difficult. With those comorbidities increasing in frequency, how will this affect blood pressure control in the future?

All of these issues — confused physicians, confused and resistant patients and difficult to treat populations — are parts of the problem. Clearly, however, there are other factors at work that we don’t yet understand. This area requires more study.

Carl J. Pepine, MD, eminent scholar and emeritus professor of medicine at the University of Florida in Gainesville, is the chief medical editor of Cardiology Today.