Hypertension Guidelines: Same Data, Different Conclusions

Henry R. Black, MD; Raymond R. Townsend, MD; Michael A. Weber, MD

Disclosures

February 11, 2014

150 vs 140 mm Hg in Patients Aged 60-80 Years

Dr. Black: So, what's a doctor to do who has to face patients like that getting conflicting advice? I would hate to be in that position for a condition I didn't know anything about. How do the doctors out there who treat most everybody -- how are they supposed to deal with these seemingly conflicting guidelines? For example, the 150 mm Hg recommendation for people over 65 -- that really wasn't tested either. [ Editor's Note: For people ≥ 60 years of age, JNC 8 recommends a goal of < 150/90 mm Hg, whereas the ASH/ISH guidance recommends < 140/90 mm Hg.] The ACCORD study,[8] for example, which was an important study and a relatively recent one, didn't test 150 against 140 mm Hg; it tested 140 against 120 mm Hg. So where did the 150 come from?

Dr. Townsend: The 150 mm Hg came from the following: Trials like SHEP and Syst-Eur enrolled people at systolic pressures of 160 mm Hg or higher and randomly assigned them either to active drug therapy or to placebo. The blood pressure during drug therapy in Syst-Eur and in SHEP was in the 140s range.

Dr. Black: But that wasn't what was tested.

Dr. Townsend: We tried to address the question based upon our understanding of the best way to interpret what evidence we do have in the clinical trial. We acknowledge that there are no good- or fair-quality randomized clinical trials (particularly in the United States) that tested 140 mm Hg vs 160 mm Hg as a systolic blood pressure goal. So we acknowledged that from the get-go, but you've got to say something about what to do in that particular situation and base it as best as you can on your understanding of what we do have in terms of clinical trial data. I won't call it evidence at this point; I'll simply call it data. Those were the achieved levels of blood pressure in the treatment group, whereas it was in the high 150s in the placebo group. So there is a 10-15 mm Hg spread. It appeared safe to lower the blood pressure down into the 140s range in those 60 years of age and older, and it had benefit associated with it. Now, the trial didn't test 140 mm Hg vs 160 mm Hg, but at the end of the day what we had that we could tether to was that at least it seemed to us that when you got blood pressure below 150 mm Hg, you did benefit without excessive harm. That was the message from the first recommendation.

Dr. Black: Michael, would you like to comment on that?

Dr. Weber: To be fair to the JNC 8 report or the report of the JNC 8 panelists, they acknowledge throughout the document -- almost to a point, Ray, where I wonder whether the same authors wrote different parts of the report -- they acknowledge that there were gaps. They do acknowledge that they could not exclude the possibility that 140 mm Hg might be a better outcome than 150 mm Hg but there just isn't the evidence. There were a couple of trials that looked at 140 mm Hg vs 150 mm Hg. They were underpowered. They were poorly performed. The data were basically useless. Ray is absolutely correct. Anything we know about less than 140 mm Hg compared with higher achieved blood pressures comes from analysis of trials where this was not the, as it were, primary endpoint. So you have to use a somewhat lower level of evidence.

There's no question that Ray is right, that SHEP did show that less than 150 mm Hg was better than more than 150 mm Hg.[3] I'm not sure you can say that about Syst-Eur because they didn't give their on-treatment values.[4] As best as I can calculate, Ray, using the data that you published as the appendix -- hundreds and hundreds of pages, and thank you that you did -- that they were probably comparing 151 vs 161 mm Hg. So they technically showed that less than 160 mm Hg is better than more than 160 mm Hg. The only trial that showed that less than 150 mm Hg is better than more than 150 mm Hg as a prespecified endpoint was HYVET.[5] But that trial was in people over 80 years of age. In the ASH/ISH guideline -- and also in the JNC 8 and European guidelines -- it's implicit; everyone agrees that if you're over the age of 80, less than 150 mm Hg is good enough. The dispute, of course, Ray, is between 60 and 80 years. I guess the argument would be -- and I don't want to sound like I'm an advocate for the minority group who dissented with the opinion -- the argument would be that if it turns out that 140 mm Hg really is better than 150 mm Hg (ie, that you're better off being at, let's say, 135 mm Hg rather than 145 mm Hg in terms of strokes, heart attacks, and major outcomes), aren't we taking perhaps an unnecessary risk in relaxing the goal? Wouldn't we be more responsible and prudent to say, "Let's stay with 140 mm Hg until we can be sure that it's okay to go with 150 mm Hg"?

Dr. Townsend: We debated this for over a year, Michael, and you can imagine that it was not a very placid give-and-take. There was passion on all sides with this particular recommendation. We uniformly agreed on most things in JNC 8 with the sole exception of recommendation #1, to the point where we acknowledged as a committee exactly what you just said, which is why we put the corollary recommendation in after recommendation #1. We made the point in the abstract and in the end of the article that clinical judgment trumps a guideline. The one thing we never said was that it was okay to take drug away from someone who is over age 60 years and let their blood pressures come up. There are no data on that. We were careful to make sure that in our message to primary care providers (JNC 8 was written for primary care), we were not recommending taking people off drug in order to let their blood pressures drift up, but I acknowledge that what you said may have merit. But when we had to come down with a number that we would choose for the systolic blood pressure, the thing we felt we could defend the most was the 150 mm Hg.

Dr. Black: I just want to highlight one thing that you said that we also said in JNC 6 and in JNC 7: that the individual clinician's judgment when dealing with the individual patient will always trump whatever a guideline says about a population. I think that's very critical. So if the doctor or practitioner thinks that the patient is doing fine at 138 mm Hg, don't take away the medicine. If they think they're doing fine at 128 mm Hg, don't take away the medicine. I think that's a message that we have to reinforce until we can prove convincingly that the higher goal is better.

I'd like to thank you both for your time. This is a very interesting issue. I don't think this is over, and I think it's very nice that we can talk about it. Thank you very much.

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