‘Major Update’ of BP Guidance for Kidney Disease
The new 2021 Kidney Disease: Improving Global Outcomes (KDIGO) clinical practice guideline for blood pressure management for adults with chronic kidney disease (CKD) who are not receiving dialysis advises treating to a target systolic blood pressure of <120 mmHg, provided measurements are “standardized” and that blood pressure is “measured properly.”
This blood pressure target — largely based on evidence from the Systolic Blood Pressure Intervention Trial (SPRINT) — represents “a major update” from the 2012 KDIGO guideline, which advised clinicians to treat to a target blood pressure of ≤130/80 mmHg for patients with albuminuria or ≤140/90 mmHg for patients without albuminuria.
The new goal is also lower than the <130/80 mmHg target in the 2017 American College of Cardiology/American Heart Association (ACC/AHA) guideline.
In a study of the public health implications of the guideline, Kathryn Foti, PhD, and colleagues determined that 70% of US adults with CKD would now be eligible for treatment to lower blood pressure, as opposed to 50% under the previous KDIGO guideline and 56% under the ACC/AHA guideline.
“This is a major update of an influential set of guidelines for chronic kidney disease patients” at a time when blood pressure control is worsening in the United States, Foti, a postdoctoral researcher in the Department of Epidemiology at the Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, summarized in a statement from her institution.
The 2021 KDIGO blood pressure guideline and executive summary and the public health implications study are published online in Kidney International.
First, “Take Blood Pressure Well”
The co-chair of the new KDIGO guidelines, Alfred K. Cheung, MD, from the University of Utah Health, Salt Lake City, Utah, told Medscape Medical News that the guideline has “two important points.”
First, “take that blood pressure well,” he said. “That has a lot to do with patient preparation rather than any fancy instrument,” he emphasized.
Second, the guideline proposes a systolic blood pressure target of <120 mmHg for most people with CKD not receiving dialysis except for children and kidney transplant recipients. This target is “contingent on ‘standardized’ blood pressure measurement.”
The document provides a checklist for obtaining a standardized blood pressure measurement, adapted from the 2017 ACC/AHA blood pressure guidelines. It starts with the patient relaxed and sitting on a chair for more than 5 minutes.
In contrast to this measurement, a “routine” or “casual” office blood pressure measurement could be off by ±10 mmHg, Cheung noted.
In a typical scenario, he continued, a patient cannot find a place to park, rushes into the clinic, and has his or her blood pressure checked right away, which would provide a “totally unreliable” reading. Adding a “fudge factor” (correction factor) would not provide an accurate reading.
Clinicians “would not settle for a potassium measurement that is 5.0 mmol/L plus or minus a few decimal points” to guide treatment, he pointed out.
Second, Target 120, Properly Measured
“The very first chapter of the guidelines is devoted to blood pressure measurement, because we recognize if we’re going to do 120 [mmHg] ― the emphasis is on 120 measured properly ― so we try to drive that point home,” Tara I. Chang, MD, guideline second author and a co-author of the public health implications study, pointed out to Medscape Medical News.
“There are a lot of other things that we base clinical decisions on where we really require some degree of precision, and blood pressure is important enough that to us it’s kind of in the same boat,” said Chang, from Stanford University School of Medicine, Palo Alto, California.
“In SPRINT, people were randomized to less than <120 vs <140 (they weren’t randomized to less than <130),” she noted.
“The recommendation should be widely adopted in clinical practice,” the guideline authors write, “since accurate measurements will ensure that proper guidance is being applied to the management of BP, as it is to the management of other risk factors.”
Still Need Individual Treatment
Nevertheless, patients still need individualized treatment, the document stresses. “Not every patient with CKD will be appropriate to target to <120,” Chang said. However, “we want people to at least consider <120,” she added, to avoid therapeutic inertia.
“If you take the blood pressure in a standardized manner ― such as in the ACCORD trial and in the SPRINT trial ― even patients over 75 years old, or people over 80 years old, they have very little side effects,” Cheung noted,
“In the overall cohort,” he continued, “they do not have a significant increase in serious adverse events, do not have adverse events of postural hypotension, syncope, bradycardia, injurious falls ― so people are worried about it, but it’s not borne out by the data.
“That said, I have two cautions,” Cheung noted. “One. If you drop somebody’s blood pressure rapidly over a week, you may be more likely to get in trouble. If you drop the blood pressure gradually over several weeks, several months, you’re much less likely to get into trouble.
“Two. If the patient is old, you know the patient has carotid stenosis and already has postural dizziness, you may not want to try on that patient ― but just because the patient is old is not the reason not to target 120.”
ACE Inhibitors and ARBs Beneficial in Albuminuria, Underused
“How do you get to <120? The short answer is, use whatever medications you need to ― there is no necessarily right cocktail,” Chang said.
“We’ve known that ACE inhibitors and ARBs [angiotensin II receptor blockers] are beneficial in patients with CKD and in particular those with heavier albuminuria,” she continued. “We’ve known this for over 20 years.”
Yet, the study identified underutilization ― “a persistent gap, just like blood pressure control and awareness,” she noted. “We’re just not making much headway.
“We are not recommending ACE inhibitors or ARBs for all the patients,” Cheung clarified. “If you are diabetic and have heavy proteinuria, that’s when the use of ACE inhibitors and ARBs are most indicated.”
Public Health Implications
SPRINT showed that treating to a systolic blood pressure of <120 mmHg vs <140 mmHg reduced the risk for cardiovascular disease by 25% and all-cause mortality by 27% for participants with and those without CKD, Foti and colleagues stress.
They aimed to estimate how the new guideline would affect (1) the number of US patients with CKD who would be eligible for blood pressure lowering treatment, and (2) the proportion of those with albuminuria who would be eligible for an ACE inhibitor or an ARB.
The researchers analyzed data from 1699 adults with CKD (estimated glomerular filtration rate, 15–59 mL/min/1.73 m2 or a urinary albumin-to-creatinine ratio of ≥30 mg/g) who participated in the 2015–2018 National Health and Nutrition Examination Survey.
Both the 2021 and 2012 KDIGO guidelines recommend that patients with albuminuria and blood pressure higher than the target value who are not kidney transplant recipients should be treated with an ACE inhibitor or an ARB.
On the basis of the new target, 78% of patients with CKD and albuminuria were eligible for ACE inhibitor/ARB treatment by the 2021 KDIGO guideline, compared with 71% by the 2012 KDIGO guideline. However, only 39% were taking one of these drugs.
These findings show that “with the new guideline and with the lower blood pressure target, you potentially have an even larger pool of people who have blood pressure that’s not under control, and a potential larger group of people who may benefit from ACE inhibitors and ARBs,” Chang said.
“Our paper is not the only one to show that we haven’t made a whole lot of progress,” she said, “and now that the bar has been lowered, there has to be some renewed efforts on controlling blood pressure, because we know that blood pressure control is such an important risk factor for cardiovascular outcomes.”
Foti is supported by an NIH/National Heart, Lung, and Blood Institute grant. Cheung has received consultancy fees from Amgen, Bard, Boehringer Ingelheim, Calliditas, Tricida, and UpToDate, and grant/research support from the National Institutes of Health (NIH) for SPRINT (monies paid to institution). Chang has received consultancy fees from Bayer, Gilead, Janssen Research and Development, Novo Nordisk, Tricida, and Vascular Dynamics; grant/research support from AstraZeneca and Satellite Healthcare (monies paid to institution), the NIH, and the American Heart Association; is on advisory boards for AstraZeneca and Fresenius Medical Care Renal Therapies Group; and has received workshop honoraria from Fresenius. Disclosures of relevant financial relationships of the other authors are listed in the original articles.
Kidney Int. Published online February 18, 2021. Guideline, Full text; Executive summary, Full text; Implications study, Full text
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