Best Practices for Measuring and Managing Blood Pressure

Putting the 2017 ACC/AHA Guidelines in Practice

Martin van Zyl, MB BCh; Randal J. Thomas, MD; Sandra J. Taler, MD


September 18, 2019

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This transcript has been edited for clarity.

Martin van Zyl, MB BCh: Greetings. I'm Martin van Zyl, cardiology fellow at Mayo Clinic. Today we will be discussing blood pressure guidelines. I am joined by my colleagues, Dr Sandra Taler in nephrology, and Dr Randal Thomas in preventive cardiology, who are both experts in this area and were involved in the writing committee of the recent American College of Cardiology/American Heart Association (ACC/AHA) guidelines.[1] Thank you for joining us, and welcome.

Dr Taler, what is different about the 2017 guidelines?

Sandra J. Taler, MD: I'm glad you asked because I think people are confused about all of the different guidelines that have come out in recent years. The 2017 ACC/AHA guideline was approved by 11 different organizations and it replaces Joint National Committee (JNC), so there is no longer a JNC guideline. The 2017 guideline is the current guideline for the United States.

Obtaining an Accurate Blood Pressure Measurement

van Zyl: What is the best way to measure blood pressure?

Taler: Part of the ability to reach new lower targets has to do with accuracy of a blood pressure measurement. If you just randomly take a blood pressure measurement, it is likely to be quite a bit higher than that person's actual blood pressure measurement, and it will be difficult to reach targets. The ideal measurement in 2019 is via an automated office blood pressure measurement that can measure the blood pressure typically between three and six times. Different algorithms are used. It will allow the person to sit without anybody in the room, take multiple measurements, average them, and give you a measurement that is much more reflective of home measurements or measurements by ambulatory monitoring.

van Zyl: Dr Thomas, what is the role of out-of-office blood pressure measurement in the diagnosis and management of high blood pressure?

Randal J. Thomas, MD: That is a key part to the guideline as well. As Dr Taler mentioned, the more measurements we have of blood pressure, the more accurate we can be in our assessment. If we only measure in the office, we will miss many patients who have true high blood pressure. On the other hand, we may overestimate some people's blood pressure. Between 10% and even as much as 50% of patients have either "white coat hypertension" or "masked hypertension,"—either higher in the office or lower in the office than we would get at home—so it is important to know what is happening at home over multiple times, if possible.

For example, we may ask a patient to measure their home blood pressure readings 3 days a week, morning and evening, and take a weekly average of those measurements so we can have a better picture of what is going on. A more typical approach may be a 24-hour ambulatory monitor, which now appears to be getting some traction for coverage by Medicare and others. That would be a way of at least getting a 24-hour monitor of a patient's blood pressure. It is very important to decide whether a patient truly has high blood pressure or whether they have normal blood pressure in the office and normal blood pressure at home.

Managing the Newly Diagnosed Patient

van Zyl: Dr Taler, what is your approach to a person with newly diagnosed hypertension?

Taler: First it is important to confirm that they actually have hypertension; the diagnosis is based on at least two readings from at least two different occasions. If somebody comes in with an elevated blood pressure on one visit, then you would want to schedule another visit for them to get it checked again before actually deciding that that person has high blood pressure. Then it depends on the severity. If somebody has an elevated blood pressure, 130/80 mm Hg or higher, then it would depend on other aspects of that person's overall cardiovascular risk as to whether you would start with lifestyle alone or whether you would use medication and lifestyle approaches.

When I see somebody with high blood pressure, there are several different things to think about. First is, why? Is this familial? Do they have a strong family history of hypertension? Is it circumstantial, weight gain, high-sodium diet? Is it unusual? For somebody who is very young or has more severe high blood pressure, I would be thinking already about a secondary cause. The amount of testing that you do really depends on that presentation. You would want to do some basic labs and a physical exam on everybody. And then there are more in-depth questions. I ask about diet and lifestyle, exercise, and other cardiovascular risk factors. Putting all of that together—whatever you think is the cause, the risk profile for that individual person—is what helps you to decide timing. Do you start with lifestyle and then see them back? Is it severe enough that you would want to start medication and lifestyle right away? Or do they need some testing done before you do anything else because there is something unusual about this presentation?

Systems-Based Approach

van Zyl: Does systems-based care help to improve the detection and management of high blood pressure?

Thomas: Absolutely. We as physicians and as healthcare providers probably tend to overestimate the quality of our care. If you were to ask us what percentage of our patients have blood pressure under excellent control, we would probably overestimate that, particularly if we do not have a system-based approach. This is a protocol-driven, evidence-based approach that involves a team and evidence-based approaches to identify patients with high blood pressure, put the treatment program in place, and then monitor their progress over time. There are a few components that we should all consider. A team-based approach involves nurses and pharmacists. It involves a team that can help with each step along the way to identify patients, monitor them, and make sure they are getting treated appropriately and adhering to their treatment.

Some other things, including electronic medical record and information technology tools, can help us connect with patients, monitor them, and follow up as well. We can also track the progress of our practice. A good study at Kaiser Permanente in Northern California[2] actually showed this. In using an EHR approach, they showed improvement in the blood pressure control of their patients. You also may want to consider quality improvement steps—things like performance measures and quality report cards to determine how you are doing in identifying and managing patients with high blood pressure.

Taler: System-based care can be extremely helpful. When a patient comes in, maybe not even for their blood pressure, it is easy to dismiss a high reading as being because they are rushed or uncomfortable and then not have it followed up. With the systems-based approach, it is flagged. Somebody other than the provider gets on it and says we need to schedule another visit or get a nurse involved. Something is done so that it is not missed. There are other things too, such as when you enter an abnormal blood pressure reading. It's red and it's harder to miss and say, "Everything is fine, I'm just going to ignore it," because it is sitting in front of you in red. Systems approaches can really help bring you back to the importance of getting the blood pressure controlled.

Thomas: Even something as relatively simple as making sure patients know how to check their blood pressure at home and making sure they are given instruction so that they know the steps to take (size of the cuff, etc.) is done much better if we have a system approach that is standard for all of the patients that we see.

Managing Uncontrolled Hypertension

van Zyl: Dr Taler, what is your approach to a patient who has hypertension that is not well controlled despite two or three blood pressure medications?

Taler: That is not unusual. As we have patients who are more complicated and with more obesity, it's difficult to get blood pressure down and it's not unusual to see somebody not controlled on two or even three drugs. The term "resistant hypertension" comes in if the blood pressure is not controlled on three different medications, and that is a good point to think about whether you might be missing something. If you started a patient on medication and they were well controlled but now have lost that control, a new condition may have developed or something may have gotten worse that you missed. I would go back and think about secondary causes; this is the time to work them up. If you can find a treatable or reversible cause, then you may get the blood pressure back under control without adding multiple additional medications.

Another common cause is high sodium intake. I don't just ask them if they eat salt, because everybody will say that they don't add any salt or eat salty food. You need to ask them how often they eat processed food, go to restaurants, or eat any kind of food that is prepared before they get to it. When we start reading labels, they realize that there is a lot more salt that they have to deal with or think about than just the salt shaker.

Another problem is nonadherence to medication, which is surprisingly common. The more medications someone is prescribed, the less likely they are taking all of those medications or taking them on schedule. I do see people who are labeled as resistant, but really they are nonadherent. You need to ask them whether the medications bother them. Look at the schedule. A complicated regimen can be very difficult to follow.

Then think about volume. Volume kind of goes along with sodium. If the person is not on a diuretic as one of those two or three agents, it is likely that that would improve their control. Or they may be on the wrong agent or the wrong dose. These are some of the issues to think about.

Thomas: Just to re-emphasize, the impact of sodium on the diet can have as much impact as one medication in lowering the blood pressure. Often patients think that if they are on the medication, they do not need to worry about sodium anymore. It's like with lipid control as well. A patient on a lipid agent may think they can eat whatever they want.

We should also look for other medications that might be interfering with the blood pressure control, such as pain medications and immunosuppressive agents. A number of drugs we see pretty commonly in a cardiology practice could cause the blood pressure to go up a bit. We may not be able to get rid of those medications necessarily, but it is good to know and identify them.

Taler: Along that same point, if you look at someone's medication list, nonsteroidal anti-inflammatory drugs (NSAIDs) are often not there. So I will specifically ask patients what they take for pain. "If you get a headache or have pain, what do you go for?" That often will bring out the fact that they are taking high doses of NSAIDs three times a week before golf. I have been amazed at how freely people do use NSAIDs.

When Is 130/80 Too Low?

van Zyl: Blood pressure targets and goals are a big part of the guidelines. When do you consider a blood pressure of 130/80 mm Hg too low for a certain individual?

Taler: That is worth thinking about. I think many providers are worried about their well-controlled older individuals falling or passing out and breaking a hip or something like that. The guidelines are set, first of all, for free-living individuals who are living independently, not in a care situation, assisted living, or a nursing home population. There are no good data to support the lower targets for that group of people. If somebody is frail, elderly, unsteady on their feet, or not tolerating their medication (eg, light-headed, feeling weak and tired), then I would absolutely back off on the target and see if adjusting the medication helps those issues.

Some people will feel that way regardless of their blood pressure; it may not be blood pressure–related. One of the helpful things about the current guideline is that for somebody who is more frail, institutionalized, or has multiple comorbidities, the target is really up to you. It is not 80, by the way; it is just the 130 in that group, and if that is too low, it is perfectly appropriate to use a higher target. Age is a big factor, but if somebody is living independently, very vital and active into their 70s, 80s, I would still try to get it to 130 or just under 130.

Thomas: In the acute care setting or when a patient is acutely ill, you would not apply those guidelines, especially after a stroke. Just to reiterate, [the guidelines are for] the free-living patients who are out and stable clinically.

Taler: Even in a hospitalized patient, I would not feel the need to go that low. You want to keep them from being too high or too low, but that is not the time to perfect their blood pressure control. The guideline does have detailed information about post-stroke, and it is really important to know those thresholds for treatment. The 2017 guideline is an excellent reference for that information.

Any Unanswered Questions?

van Zyl: Dr Thomas, are there any unanswered questions that require further research?

Thomas: There are always new things to discover and new populations to test things in. One thing that the writing group recognized is that we do not really know how much prevention and early treatment help compared with later identification and treatment. We would assume that the sooner we identify high blood pressure, the better the outcomes will be. It has really never been tested, so it would be an important thing to look at. A number of studies are looking at what is happening with early detection and whether it does help. We assume that it would, and it may surprise us how big that improvement would be. That would be one area, I think, to consider.

van Zyl: Dr Taler, are any lifestyle changes effective at controlling blood pressure?

Taler: I alluded to lifestyle earlier, but it is worth highlighting again that lifestyle can be equivalent to one or two medications. There are different options but I would not have a patient take on all of them at once. The guideline has a very nice table that gives the estimated effect of each different lifestyle change. You would expect about 5-10 mm Hg systolic and 2-3 mm Hg diastolic reduction with a lifestyle change. That could be regular exercise, limiting sodium, weight loss, relaxation options, increased potassium intake in the diet. A number of them are listed, so I would strongly encourage patients to follow those guidelines or take on one or two at a time in addition to medication if they need medication. Some people would not need medication if they adopt a lifestyle change.

Thomas: It is important to point out to patients the potassium issue. Lowering the sodium will help lower the blood pressure, but increasing the potassium with more fruits and vegetables, for example, can help lower the blood pressure. Another [lifestyle change is] decreasing intake of alcohol. Many patients are very sensitive to alcohol. I would encourage them to decrease or discontinue alcohol if the blood pressure is difficult to control.

van Zyl: Thank you, Dr Taler and Dr Thomas, for these very important insights, and thank you, the audience, for joining us on | Medscape Cardiology.

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