As we all know from long experience, hypertension is the single most commonly seen and treated condition in primary care medicine. It is an important risk factor for strokes, heart attacks, kidney failure and overall death. It has been exhaustively studied. And yet there is still significant controversy over hypertension, including how to define it and what the best agents for treatment are.
Against this background, The 2014 Evidence-Based Guideline for the Management of High Blood Pressure in Adults was released last December in JAMA. It was written by the 8th Joint National Committee, and so, of course, is referred to as JNC 8.
JNC 8 has a couple of important and surprising changes from JNC 7. One of these, at least, is controversial enough that some members of the committee rebelled and released a dissenting “Minority Report” (apologies to Tom Cruise). Today’s JailMedicine post is a summary of JNC 8 recommendations and changes to JNC 7.
JNC 8 Background
Interestingly, JNC 8 had no official sponsor. The National Institutes of Health (NIH), via their National Heart, Lung and Blood Institute (NHBLI), had sponsored each of the previous seven JNC reports. However, the NHBLI had previously announced that they are no longer in the guideline writing business . The JNC panel chose not to pursue other sponsors, in part because of concerns about conflict of interest. Bottom line: this may be the last JNC report ever. And that’s too bad. Read it well!
JNC 8 only considered data from randomized controlled trials (RCTs). This is in contrast to JNC 7, which also considered evidence of lesser quality, such as observational studies and meta-analyses. Emphasis on these RCTs led to the JNC 8 recommendation to change blood pressure goals in the elderly (discussed below). A minority of panel members felt that lesser quality evidence should also have been considered on this issue and published a dissenting view.
JNC 8 is more limited in scope than JNC 7. It does not discuss all issues of hypertension like JNC 7 did. For example, JNC 8 does not discuss “pre-hypertension” or hypertension in patients younger than 18. JNC 8 also only discussed four drug classes in its treatment recommendations.
JNC 8 does state that JNC 7’s definition of hypertension as a blood pressure greater than 140/90 “remains reasonable.”
This was JNC 8’s most important new recommendation. And the most controversial.
The new blood pressure goal for patients aged 60 or older is 150/90.
JNC 8 found no additional benefit to lowering the blood pressure below 150/90 in this age group in terms of coronary heart disease, stroke, heart failure or death. On the other hand, they noted that aggressive blood pressure treatment in this age group does have several potential adverse consequences.
This is the recommendation disputed by a minority of the JNC 8 panel. If you would like to read their reasoning, you can find it published here in the Annals of Internal Medicine.
In those patients below 60 years old, the goal of diastolic blood pressure control is less than 90mm HG.
Not 85. Not 80. 90mm HG.
In patients younger than 60, the goal of systolic blood pressure control is to lower the systolic blood pressure to below 140mm HG.
Interestingly, JNC 8 found no RCT, really, that supported this particular recommendation. So the goal of lowering systolic blood pressures to less than 140mm HG, when rated for quality, is an “expert opinion,” or “E,” recommendation. (Remember that the evidence behind recommendations such as this are rated on a scale ranging from A—the strongest evidence, to B, less so, to C even less certainty, to a low of E, which means there is no good objective evidence for this recommendation at all, but nevertheless, clinical experts believe it is true).
Recommendation 4 and 5
These recommendations represent the second significant change from JNC 7. JNC 7 had different blood pressure goals for certain co-morbid conditions. JNC 8 now says that the blood pressure goals are the same for everyone, whether they have a chronic disease or not.
Recommendation 4 says that the blood pressure goal for those patients with chronic kidney disease is 140/90, just like every other hypertensive patient.
Recommendation 5 says that the blood pressure goal for diabetics is, again, 140/90.
Remember that JNC 7 had recommended getting the blood pressure in diabetics down to below 130/80. JNC 8 now says that this goal is “not supported by” the available evidence.
The initial drug of choice for the treatment of hypertension in non-black patients (including those with diabetes) should be one of these four classes of medications:
1. Thiazide diuretic
2. Angiotensin-converting enzyme inhibitor (ACEI)
3. Angiotensin receptor blocker (ARB)
4. Calcium channel blocker (CCB)
JNC 8 concludes that each of these has comparable beneficial effects in reducing death, stroke, heart disease and kidney disease.
JNC 8 does not recommend any of the following for the initial treatment of hypertension:
1. Beta- blockers. This is important because it is still so commonly done. I see patients all the time in my jails who are taking only a beta-blocker for their hypertension.
2. Central alpha-2 adrenergic agonists like clonidine. This is important because these drugs are now being commonly prescribed as psychiatric drugs. And patients on clonidine will say that it is being used to dually treat their nightmares and their hypertension.
3. Alpha blockers like Prazosin.
4. Loop diuretics like Lasix.
5. Vasodilators like hydralazine
6. Aldosterone receptor antagonists like spironolactone.
In black patients (including those with diabetes), the initial drug of choice should be either:
1. Thiazide diuretic
2. Calcium channel blocker.
Patients who have chronic kidney disease as well as hypertension should be initially treated with either:
1. ACE inhibitor
JNC 8 acknowledged that the situation in black patients who also have kidney disease is a little problematic. Basically, they say if the black patient with kidney disease has proteinurea, use an ACEI or an ARB. But if the black patient with kidney disease has no proteinuria, you can start with a diuretic or CCB if you like, but always use an ACEI or an ARB as the second add-on drug, if necessary.
Selections or recommendation 9 are presented here verbatim, with my comments in italics:
1. 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 class in recommendation 6 (thiazide-type diuretic, CCB, ACEI or ARB). This is important because I often see drug regimens being changed sooner than one month in corrections, because it is so easy to monitor blood pressures more frequently than this.
2. If goal BP cannot be reached with two drugs, add and titrate a third drug from the list provided.
3. Do not use an ACEI and an ARB in the same patient.
4. If goal BP cannot be reached using the drugs in recommendation 6 because of a contraindication or the need to use more than three drugs to reach goal BP, antihypertensive drugs from other classes can be used.
5. Referral to a hypertension specialist may be indicated for patients in whom goal BP cannot be attained using the above strategy.
Concise Synopsis of the Most Important Changes in JNC Hypertension Recommendations
Remember these points if nothing else!
1. In Adults 60 and older, the new BP treatment goal is 150/90 or below.
2. The BP treatment goal for all patients under the age of 60 is 140/90. This includes patients with diabetes and kidney disease.
3. Use a thiazide diuretic, a calcium channel blocker, an ACE inhibitor or an ARB preferentially to treat hypertension. Do not routinely use other drugs, including beta-blockers.