What PCPs Need to Know About the New Blood Pressure

Okay, it doesn’t get any bigger than this! Today we’re going to discuss the new guideline on hypertension from the American College of Cardiology [ACC] and American Heart Association [AHA]. These guidelines are endorsed by a boatload of organizations, but not the AAFP (the American Academy of Family Physicians), the ACP (American College of Physicians), or the ISH (the International Society of Hypertension). We’ll touch on some of the differences in their guidelines at some point during our discussion.

I’m going to apologize ahead of time. This will be a little longer than I usually like our discussions to go, but this is an important guideline with a lot of information — big change here. The important take-home point from this ACC guideline is that the blood pressure target goal is < 130/80 mm Hg for almost all adults. This goal is true regardless of age, regardless of risk factors, and is true for people with diabetes. The exception to that goal is people who are pregnant or individuals who are older and/or frail.

The classification of blood pressure is as follows: Blood pressure category of normal is a systolic < 120 mm Hg, diastolic < 80 mm Hg; elevated is 120-129 mm Hg with a diastolic < 80 mm Hg; stage 1 hypertension: 130-139/80-89 mm Hg; stage 2 hypertension: ≥ 140/≥ 90 mm Hg. The classification, remember, has to be based on two or more careful readings obtained on two or more different occasions.

Also important: The category formerly called hypertensive urgency has been eliminated, and instead the term “severe hypertension” is being used for a systolic > 180 mm Hg or a diastolic > 120 mm Hg. And this is to clarify that treatment for this group of individuals is best accomplished with oral medicines in an outpatient setting with close follow-up, as long as there are not other acute consequences of the high blood pressure. They don’t need to go immediately to the emergency room.

Next, be aware of the potential for secondary hypertension. That is when the elevated blood pressure is due to a specific cause, other than essential hypertension. Secondary hypertension is the most common when the blood pressure is higher, when it’s treatment resistant, if it’s sudden onset or early onset, [with] diastolic hypertension in older adults, and target organ damage discrepancies that are disproportionate to the duration or the severity of hypertension.

The full list of secondary causes is very long. We’re not going to cover it, but we’re going to touch on the important ones. The common ones include primary hyperaldosteronism (we’ll come back to that in a minute), obstructive sleep apnea (often forgotten), chronic kidney disease, medications/alcohol, as well as renovascular hypertension. The new big thing that’s emphasized in these guidelines is primary hyperaldosteronism, and the point is that it’s much more common than we used to think it was. It occurs in 5%-10% of patients with hypertension and up to 20% of people with resistant hypertension, and it is often not associated with hypokalemia. See my recent column on the AACE [American Association of Clinical Endocrinology] guidelines on this topic for more details. The ACC guideline suggests the initial test should be a simple blood draw for plasma aldosterone, renin activity, and a plasma aldosterone to renin activity ratio. Most antihypertensive medicines can be continued except for mineralocorticoid receptor antagonists (MRAs), which have to be stopped prior to initial screening.

Where does home blood pressure monitoring fit in? Critically important, that’s where. For both initial diagnosis and follow-up blood pressure decisions, home blood pressure monitoring is recommended because it more strongly predicts cardiovascular outcomes than in-office blood pressure. It also helps keep people engaged/invested in their own treatment.

How about lab tests? Tests that are recommended upon diagnosis include a CBC, a basic metabolic panel, a lipid panel, glucose or an A1c, a TSH, a urinalysis, and — listen carefully — a urine albumin to creatinine ratio [UaCr] as well as a 12-lead EKG. I want to emphasize the UaCr is now included in routine recommendations for testing of people with hypertension. This is a new recommendation and it encourages us to detect early renal damage from hypertension, which is important now that there are medications that are effective at slowing the progression of CKD [chronic kidney disease].

Let’s move on now to treatment. Everybody ought to be trying to have a healthy lifestyle — that includes you and me — and it includes maintaining or achieving a healthy weight, following a healthy eating pattern, reducing sodium intake, increasing dietary potassium, engaging in a moderate or even a vigorous physical activity program, managing stress (yeah, right), and reducing or eliminating alcohol intake.

Where do medicines fit in? For lower-risk individuals with stage 1 hypertension — that is a blood pressure of 130-139/80-89 mm Hg — lifestyle modification is recommended as being able to be tried for 3-6 months, but if it’s not successful, then medicine should be started. Remember, blood pressure needs to be confirmed on a separate occasion before a diagnosis is made and treatment is initiated.

Who is at lower risk? What do they mean by “lower-risk individuals”? Lower risk here is defined as a 10-year cardiovascular risk of < 7.5% using the PREVENT equation. We’ll talk in a little bit about what that equation is and how it’s different than the old ASCVD equation that we’re used to using. For individuals with stage 1 hypertension who have established ASCVD, diabetes, CKD, or elevated cardiovascular risk (defined as > 7.5% 10-year risk on the PREVENT equation), medication should be initiated at that time — at the same time as emphasizing lifestyle modification.

How about stage 2 hypertension (again, defined as a blood pressure ≥ 140/90 mm Hg)? The guidelines recommend starting medication and lifestyle modification at the same time. I suspect there are some of us who really believe in lifestyle modifications, since it can shave 5-10 points or more off of one’s blood pressure; and may feel that for selected, motivated patients, lifestyle modification is not a bad first choice to really avidly emphasize.

Now, I know what some of you are thinking: What happened to just starting medicines at a level above 140 mm Hg systolic for everyone? The rationale for the 130 mm Hg target is that since the publication of the 2017 ACC/AHA guidelines which introduced the 130 mm Hg target for high-risk individuals, there have been a number of trials confirming the benefit of that 130 number in high-risk individuals. There isn’t the same strength of data for lower-risk individuals. For some thoughts on that, see my viewpoint that was published in the journal Circulation for a discussion of this issue.

Of note, the AAFP and the ISH, in their guidelines, emphasize a blood pressure [goal of] < 140/90 mm Hg with an option of a lower blood pressure goal for those at higher risk. Also of note, since people with diabetes are at high cardiovascular risk, the American Diabetes Association 2 years ago revised their blood pressure goal to be < 130/80 mm Hg for people with diabetes. See my Medscape column (link below) comparing the recommendations to the different organizations’ for more details on this issue.

Now, let’s talk about the PREVENT calculator. What is that? A lot of us might be saying the PREVENT calculator is basically an updated version of the old ASCVD risk calculator — technically called the Pooled Cohort Equation or PCE calculator — that we’ve used for years. But there’s an important difference, which is that the PCE was based on evidence from about 25,000 people from 1960-1990. The PREVENT calculator is based on over 3 million people in a more current dataset, and so more accurately estimates current risk. Turns out that this is not trivial because the PCE calculation overestimates current risk by quite a good deal.

It’s important to understand that the reason the current guideline defines high risk as ≥ 7.5% on the PREVENT calculator is that 7.5% calculated with PREVENT is equivalent to a Framingham Risk Score threshold of ≥ 15%, which was the inclusion criteria for the SPRINT trial. The PREVENT calculator is available from the AHA website and is on MDCalc. I’ve put links down below so that you can easily find that.

Let’s now talk about which medicines to use. For initial therapy, the recommendations have not changed: thiazide-type diuretics, long-acting dihydropyridine, calcium channel blocker, an ACE inhibitor, or an ARB. In adults with stage 2 hypertension, the guidelines recommend initiation of antihypertensive drug therapy with two first-line agents of different classes, ideally in a single-pill combination. Though, they note that there are no randomized trials that have compared initial stepped care with initial combination therapy and that either approach can be effective.

Finally, let’s talk about blood pressure goals. In adults with confirmed hypertension, a systolic blood pressure goal of at least < 130 mm Hg is recommended, with encouragement to achieve a systolic blood pressure < 120 mm Hg. I think many of us are surprised to see the 120 mm Hg suggestion. And this is given a level A recommendation for those who are at increased risk for cardiovascular disease and a level 2b recommendation, meaning not as strong evidence, in adults who are not at increased risk. The guideline notes, though, that the evidence to support a blood pressure goal — systolic — < 130 mm Hg is strong, and it’s not as strong for a systolic blood pressure goal < 120 mm Hg.

So, what are the big, important take-home points here?

• A systolic blood pressure goal < 130 mm Hg for most adults
• A new recommendation to routinely check a UaCr
• When considering secondary causes, think about primary hyperaldosteronism.
• Use home blood pressure monitoring — it’s helpful.
• Elimination of the term “hypertensive urgency,” which is now replaced with the term “severe hypertension” so it can be managed as an outpatient.
• And don’t forget lifestyle modification! Okay — that isn’t new in the guidelines, but I’m emphasizing it because I’m telling you that’s important.

This is an important update with a lot of subtleties and something that we see in the office every single day and so need to know really well. As always, I am interested in your thoughts. Please put them in the comments section. For Medscape, I’m Dr Neil Skolnik.

Lead image: Medscape, LLC