January 13th, 2014
Minority Report: Five Guideline Authors Reject Change in Systolic Blood Pressure Goal
It didn’t seem possible, but the guideline situation just got even more confusing. Last December, after years of delay and other twists and turns, the Eighth Joint National Committee (JNC 8) hypertension guideline was published in JAMA. The previous guideline recommended that all adults have a target systolic blood pressure below 140 mm Hg. In the new guideline, the target remained the same for adults under 60 years of age but for people over the age of 60 the new guideline set a more conservative, easier-to-achieve target of 150 mm Hg or lower.
Now, however, five of the seventeen JNC 8 authors have written a commentary, published in Annals of Internal Medicine, disagreeing with this change. They say they are in agreement with the other major recommendations of JNC 8 but that they reject the new target, arguing that the evidence does not support the change, and predict that the change may well lead to harmful consequences.
The JAMA article was “was not the place to discuss a dissenting view” of the recommendation, said the first author of the Annals dissent, Jackson T. Wright, Jr, in an interview. The Annals article provides a forum for the minority position and outlines the key areas of disagreement.
The Annals authors write that the evidence to support changing the target “was insufficient and inconsistent with the evidence supporting the panel’s recommendations.” They argue that the new target could reverse gains in blood pressure treatment achieved in recent decades. Currently 82% of people with hypertension are receiving treatment, and the median systolic blood pressure of people being treated is 136 mm Hg. “If we go to the higher blood pressure target that would mean potentially backing off on therapy in over half of the patients who are already below 140,” Wright said.
Furthermore, the median blood pressure for the population not currently being treated is 152 mm Hg. According to Wright, this means that about half of this group would not receive treatment with the new target.
A central argument is that the revised goal could reverse the gains in public health of recent years. Both coronary heart disease and stroke mortality “have been decreasing as the blood pressure has been declining and has been decreasing at twice the rate in those over the age 60 as those under age 60,” said Wright.
They note that other guideline groups have stayed with the 140 mm Hg goal. In addition, since people over age 60 are much more likely to die of cardiovascular disease, “this means we would be backing off on patients at highest risk,” said Wright.
Finally, the authors write that although there are two trials that support the lower target in patients over 60, “We failed to identify any evidence of the risk benefit of treating to a systolic blood pressure of less than 140 in those under age 60, and yet we still we recommended a target of less than 140 in that population,” said Wright. He said the Annals authors were particularly concerned about reducing treatment in the high-risk subpopulations of people over 60, including African Americans, patients with established cardiovascular disease, and patients with multiple cardiovascular risk factors.
Response to Confusion
In their rejection of the lower target, the Annals authors appear to have gathered some key support. The American College of Cardiology and the American Heart Association, which have assumed responsibility for developing and publishing cardiovascular guidelines, said in a statement that they continue to “recognize the most recent hypertension guidelines, published in 2004 by the Joint National Committee (JNC 7), as the national standard.” In other words, they are ignoring the JAMA JNC 8 publication and tacitly endorsing the old targets. The ACC and the AHA said they had “begun the process of developing” a new hypertension guideline and anticipate that they will publish it in 2015 “for clinicians to follow as the national standard for hypertension prevention and treatment.”
It appears unlikely that any consensus will emerge before then. Some observers think that the confusion may turn out to be beneficial. Harlan Krumholz made the following comment:
This turn of events is quite surprising and adds to the uncertainty around treatment. It may be that we are seeing the beginning of the end of monolithic treatment goal recommendations as the uncertainty should highlight the importance of personalizing treatment according to patient preferences.”
Sanjay Kaul thinks the difference in opinion “reflects the uncertainty in the evidence”:
When the same evidence is viewed differently by different individuals, it only reflects the uncertainty in the evidence. In my opinion JAMA should have published this minority report. Nonetheless, I am glad that the dissenting opinion is getting the proper attention it deserves. I tend to agree with the authors of this minority report that the quality and the quantity of evidence is not persuasive enough to formally change BP treatment thresholds, even if one can arguably disagree with them. Recommending different treatment thresholds is only going to end up confusing practicing clinicians, making them more skeptical of guideline recommendations and ultimately detracting from the Institute of Medicine’s stated goal of developing trustworthy guidelines.”