High Blood Pressure: The Not-So-Silent Killer

Q&A with Dr. Henry Black, Director of NYU Langone’s Hypertension Program

High blood pressure, or hypertension, afflicts one in three Americans. It can almost always be controlled with proper treatment, but an estimated 30% of those with hypertension don’t even know they have it. Many of those who do know are not treated to the recommended goal, putting them at risk for a number of serious health problems, including damage to their kidneys, eyes, and heart, and significantly increasing their likelihood of suffering a stroke or heart attack. High blood pressure contributes to 75% of all strokes and heart attacks, and it is particularly deadly in African-Americans. To mark National Heart Month in February, news & views asked Henry Black, MD, director of the Hypertension Program in the Center for the Prevention of Cardiovascular Disease, a component of the Leon H. Charney Division of Cardiology, to address these and other related issues.

How did hypertension become such an epidemic?

It’s a combination of our population growing older and becoming fatter and less active. Our arteries stiffen as we age, causing the systolic blood pressure to rise. If you live long enough, you’re almost certain to have hypertension. We also consume much more sodium in the form of salt than we need to be healthy. All of these are contributing factors, in the US and worldwide.

Has the definition of high blood pressure changed in recent years?

For decades, we have defined hypertension as a condition in which the blood pressure is 140 systolic, the upper number, or higher or 90 diastolic, the lower number, or higher at least three times under appropriate conditions. At least 72 million Americans (23% of the population) are hypertensive. We coined the term "prehypertension" for those 45 million Americans whose blood pressure is between 120 to 139 systolic and/or 80 to 89 diastolic. We now know that patients with blood pressure measurements in this range are already at increased risk for all of the problems that hypertensive patients have.

How often should people have their blood pressure checked?

Considering how much is known about the risks of being hypertensive, it’s very surprising that so many people still ignore it. We now recommend that all adults have their blood pressure measured at least every other year, and annually if their blood pressure was between 120 to 139 over 80 to 89 millimeters of mercury in the past.

How should blood pressure be measured in the doctor’s office?

In our program, we measure blood pressure in a quiet room after the patient has been resting for five minutes, having had no coffee or cigarettes for at least 30 minutes. We check it twice in each arm and in three different positions: lying down, sitting, and standing. Once we’ve established which arm has the higher reading, we use that arm from then on. We use a validated automated machine, and we average all of these numbers to get an accurate assessment. If only one reading is taken, it should be done in a sitting position with both feet on the floor and the machine at heart level, following the same guidelines for rest, coffee, and cigarettes.

Can high blood pressure always be detected this way?

No. Recently, we’ve learned that some patients have "masked hypertension," meaning that their blood pressure is normal in the doctor’s office but high outside. This is the opposite of "white coat hypertension," where blood pressure is high in the doctor’s office but normal elsewhere. If I suspect masked hypertension, I’ll recommend home monitoring to confirm it. The patient should use a validated home blood pressure monitor and measure their blood pressure twice a day, at the same time each day, regardless of how they feel, for two to three weeks.

Should we all be measuring our blood pressure at home?

Some experts believe that every home should have a blood pressure device, the way every home has a thermometer. I disagree. To best understand out-of-office blood pressure, take it under the same conditions each time and discuss the readings with your doctor.

If you’re prehypertensive, what should you be doing about it?

Drug therapy is not recommended. What is helpful is lifestyle modification: losing weight, reducing dietary sodium intake, exercising regularly, and managing stress. The first two are the most important. If you do some or all these things, your blood pressure may drop about 10 points systolic and 5 points diastolic— enough to keep many people who are prehypertensive from becoming hypertensive. For those who are already hypertensive, however, lifestyle modification usually isn’t enough, and drugs are usually necessary.

What does this group need to do?

For most hypertensive people, the only way to reach the goal blood pressure of below 140 over 90—and below 130 over 80 for those with diabetes, kidney disease, heart failure, or a previous heart attack—is with medication. In my opinion, there are three primary classes of hypertension drugs: diuretics; so-called RAAS [renin-angiotensin-aldosterone system] blockers, such as ACE [angiotensin-converting enzyme] inhibitors and ARBs [angiotensin receptor blockers]; and calcium channel blockers. There are four other commonly used and approved antihypertensive drug classes and about 150 individual drugs and drug combinations now available. All have proven efficacy and acceptable side effects. So every patient has at least five or six good options. It’s recommended that people at 160 over 100 and above start with two drugs, and those at 140 to 159 and/or 90 to 99 start with one.

What’s the biggest misconception about hypertension?

That it’s curable. For most people, hypertension is a lifelong condition. If you find a drug combination that works, that you can afford and tolerate, don’t stop it.

Can anyone’s hypertension be controlled with the right drugs?

Almost anyone. But it requires a partnership between doctor and patient. About 60% of treated Americans with hypertension are at their goal blood pressure.

What will it take to reach 100%?

Fortunately, today’s blood pressure medications are much easier to tolerate, and we’ve learned how to treat with low-dose combinations of drugs instead of the very high doses we used in the past. Everyone who treats hypertension should be familiar with the latest recommendations and how to implement them, and should refer patients who aren’t responding to a hypertension specialist. Finally, patients should know their numbers. If a doctor sends you home when your blood pressure is above goal and doesn’t do anything about it, you need to ask why. If the answer is unsatisfactory, it might be time to get a new doctor.

For more information about preventing and treating hypertension, call 212-263-7751.