December 18th, 2013
Missing High Blood Pressure Guideline Turns Up in JAMA
Larry Husten, PHD
After years of delay and many twists and turns, the hypertension guideline originally commissioned by the NIH has now finally been published in JAMA. The evidence-based document contains a major revision of hypertension treatment targets and includes new and somewhat simplified recommendations for drug treatment.
The previous U.S. hypertension guideline was published more than a decade ago. After many delays, the new guideline was ready for publication earlier this year, but then the NIH decided to get out of the guidelines business. The American Heart Association and the American College of Cardiology assumed responsibility for the development and publication of cardiovascular guidelines and last month published four new cardiovascular guidelines, with the notable exception of the hypertension guideline. As an accompanying JAMA editorial explains: “Rather than submit the hypertension guideline for review by these organizations, the panel members submitted the guideline to JAMA, where it underwent both internal and external peer review.”
The big headline of the new guideline is an important change in treatment targets. The previous guideline recommended that all adults have a target systolic blood pressure below 140 mm Hg. For people with diabetes or kidney disease,/ the target was even lower, <130 mm Hg. In the new guideline, the target remains the same for adults under 60 but eliminates the lower target for people with diabetes and renal disease. Most importantly, however, for people 60 and over the new guideline establishes a more conservative, easier-to-achieve target of 150 mm Hg or lower.
The authors write that they have not established a new definition of hypertension: “the panel believes that the 140/90 mm Hg definition from JNC 7 remains reasonable.” Lower is still better, at least when it occurs naturally: “The relationship between naturally occurring BP and risk is linear down to very low BP.” The change in target is based, instead, on the lack of evidence showing that drug treatment to the lower levels is better.
For nonblack adults, the guideline recommends starting drug treatment with an ACE inhibitor, an ARB, a calcium-channel blocker, or a thiazide-type diuretic. For blacks, the guideline recommends starting with a calcium-channel blocker or a thiazide-type diuretic. People with chronic kidney disease should receive an ACE inhibitor or an ARB. (Although once a cornerstone of antihypertensive therapy, beta-blockers are no longer recommended for initial treatment.)
If goal blood pressure is not achieved after a month, then the guideline recommends increasing the drug dose or adding a second drug. Blood pressure should be monitored until the treatment goal is reached. A third drug can be added if necessary, but an ACE inhibitor and an ARB should not be used together.
One important difference between the hypertension guideline and the AHA/ACC guidelines released last month is the approach to risk assessment. Where the AHA/ACC recommendations were based on an assessment of total cardiovascular risk, the hypertension guideline is more narrowly focused on blood pressure. Also, as noted in another accompanying editorial, following the new hypertension guideline will lead to less treatment for elderly people, while the AHA/ACC guidelines lead to more treatment in these patients. “Such divergent philosophies may cause confusion among clinicians and patients alike,” write Eric Peterson, J. Michael Gaziano, and Philip Greenland.
The guideline offers a frank admission that many of the recommendations are based on expert opinion and not clinical trial evidence.
5 Responses to “Missing High Blood Pressure Guideline Turns Up in JAMA”
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Franz Messerli and Sripal Banagalore sent the following comment about the new guideline:
To our way of thinking these guidelines are a classic example that a committee is defined by the dictum of “Lots of people say collectively what nobody believes individually.” This is perhaps best illustrated by recommendation 1 which is evidence-based grade A. Obviously this recommendation could not be accepted by all the authors and had therefore to be supplemented with a “corollary recommendation” which is solely eminence-based i.e. expert opinion grade E. Does this indicate that some authors believe that their own (expert) opinion is better than objective evidence?
The authors start out with the very promising statement “This report takes a rigorous, evidence-based approach to recommended treatment thresholds, goals and medications in the management of hypertension in adults.” This intent is bonum et laudabile but when one looks at the linchpin of the guidelines, i. e. the box of recommendation for the management of hypertension one rapidly becomes disheartened. Of the 10 recommendations only 2 are grade A (based on evidence that the net benefit is substantial), 2 are grade B, 1 is grade C and no less than 6 are grade E (expert opinion, net benefit is unclear). Clearly therefore although the intentions were good the execution falls short, for the great majority of the recommendations eminence trumps over evidence.
A few other issues deserve to be mentioned:
1.“Thiazides” continued to be recommended as initial therapy. on an equal basis with ACE inhibitors, ARBs and CCBs. This may be acceptable in the elderly but certainly not in younger patients who will be exposed to these drugs that are known to increase the risk of new onset diabetes over years and decades.
2. It’s no longer acceptable to lump all the “thiazides” into the same class because only for chlorthalidone and indapamide evidence does exist of reducing morbidity and mortality. Hydrochlorothiazide, the most common prescribed antihypertensive in its usual dose of 12.5 to 25mg per day has never shown to reduce the risk of heart attack, stroke or death.
3. Disappointingly, no mentioning is made of 24-hour ambulatory blood pressure monitoring which is a very useful tool and features prominently in the NICE and European guidelines.
4. Table 4, “Evidence-based dosing for antihypertensive drugs” seems to be an exercise in cherry picking and we are not informed why some drugs are mentioned and others are left out. Among the CCBs for instance, diltiazem is listed but verapamil, felodipine and nifedipine are absent.
5. On a positive note- the relegation of the beta blockers from their first line status in JNC 7 to 4th line add-on therapy. There never was any evidence for this class of drugs to be used on an equal basis with agents such as chlorthalidone, amlodipine etc.
Very much agree with the above comments.
While they have appropriately backed off on the thresholds a bit and suggested there may not be great evidence for some populations which is good – the following facts about the guidelines are a bit worrying
In the 14 page, roughly 10,000 word document
1) The word preference is only used once “each strategy is an acceptable pharmacologic treatment strategy that can be tailored based on individual circumstances, clinician and patient preferences, and drug tolerability”
2) There is only one mention of harm – “ACE and ARBs can increase creatinine and potassium”
3) There is no mention of CVD risk assessment of any kind
4) There is no mention of absolute or EVEN relative benefits
5) And they state medication costs were “beyond the scope of this review”
Given there is nothing about the magnitude of the benefit and barely no mention of harms (side effects and cost etc) above how do clinicians use these guidelines to present benefit and harm information to inform and guide patient decisions?
Thoughts
I have issue with this:
Recommendation 9
“…. If goal BP is not reached within a month of treatment, increase the dose of the initial drug or add a second drug from one of the classes in recommendation 6…”
Many patients are on multiple medications & I think it’s important to maximize the dose of a tolerated medicine before adding yet another (oftentimes costly) therapy.
It is interesting that the lipid guidelines were very focused on risk and absolute benefit – and the high blood pressure guidelines seemed not to care. Also, speaking of inconsistency, the lifestyle guidelines were all in on surrogate markers – in contrast to the lipid guidelines. Where was the coordination of these committees while they were under the NHLBI?
What defines a guideline? Does it need endorsement by an independent body? These recommendations, although I agree with them, do not carry an endorsement and in fact in the disclaimer reads “The views expressed do not represent those of the NHLBI, the National Institute of Diabetes and Digestive and Kidney Diseases, the National Institutes of Health, or the federal government.” Therefore, I ask- are these actually guidelines?