So, here is my brief (ie, briefer than usual) review of JNC-8 (see doi:10.1001/jama.2013.284427). This is a short 14-page document, recommending the following:
–in people over 60 years old, initiate drug treatment to lower BP to <150/90 (but okay to keep at systolic<140 if already there based on prior guidelines and if well-tolerated, per expert opinion, though no clear benefit to doing so)
–in those younger than 60, begin drugs to lower diastolic <90, mostly based on really old studies from the 1970s, which only looked at diastolic blood pressure. This recommendation is stronger for those 30-59yo than 18-29yo (ie, no RCTs showing anything in the younger group)
–in those younger than 60yo, use a systolic goal of <140 (expert opinion, since lack of studies, as in last point)
–in those >18yo with CKD (chronic kidney dz, with GFR<60, or people of any age with alb/creat ratio >30), treat to lower BP to <140/90. this is based on expert opinion. No signif data that 130/80 prevents either cardiovasc or renal outcomes. JNC-8 not address those over 70yo with CKD, since the eGFR calculation models did not include them.
–those >18 yo with diabetes, use drugs to lower BP to <140/90. lack of evidence that lower BP helps
–for general non-black population, including those with diabetes, initial treatment should be thiazide-type diuretic, CCB (calcium channel blocker), ACE-I (ACE inhibitor) or ARB (angiotensin receptor blocker), noting that in some trials thiazide more effective than CCB or ACE-I (eg ALLHAT).
–for the general black population, including diabetics, initial treatment with thiazide or CCB. as with last point, the ALLHAT study weighed in heavily. (note that ACE-I/ARB is not initial choice in diabetics)
–for those >18 yo with CKD and htn, initial therapy should include ACE-I or ARB. Includes all patients, independent of race or diabetes. though the recommendation for black pts is expert opinion here. no data to support ACE-I or ARB if older than 75yo
–if BP goal above not achieved in 1 month, can either increase dose of initial drug or add another of the initial 4 classes, then a third drug from the list if still needed, but do not add combo of ACE-I plus ARB. Then can use drugs of other classes and consider referring to specialist if BP not achieved with the above strategy. (expert opinion)
So, pretty simple. only 2 goals. older people (>60yo) have target of <150/90. Everyone else <140/90
A few observations:
- No preference in choice of initial meds between thiazide-type diuretics, CCBs, ACE or ARB.
–notable loss of b-blockers from list (I think justified by the cochrane anaylses showing inferior outcomes to other drugs)
–thiazides still listed in the main group, unlike with the NICE recommendations. hydrochlorothizide (most commonly prescribed) may not be the best, per prior blogs, but one issue with chlorthalidone is hypokalemia since only the 25mg dose is available to us in the US (recent study showed that chlorthalidone no worse than HCTZ in causing hypokalemia if give the 12.5mg dose). It is perhaps notable that there is as much new-onset diabetes with thiazides as with statins, though no comment here (mechanism??? — old studies posited that hypokalemia from the diuretics decreased b-cell insulin release, as documented in animal studies)
–These are just “guidelines” not to supercede clinical judgment, as stated. But no clear comment that we should look at underlying conditions to choose the antihypertensive (JNC-7 had chart, suggesting for example that b-blockers be used preferentially if patient is s/p MI or has CHF). I still think (and suspect committee members would agree) that we should look at underlying issues (not give diuretics in pt with hyperuricemia, give CCB if patient has raynaud’s…….), though not in guidelines
–they do not explicitly recommend starting with 2 drugs at the same time for anyone (and they do not stratify aggressiveness of therapy by initial blood pressure), though they do note that some on the panel did suggest 2-drug combo in those with bp>160/100.
- No detailed suggestions about which second meds to add. There are data from small studies which make some sense: if start with CCB or diuretic, then add ACE or ARB, since there is some synergy between the “volume-effective” meds in the first category and the “renin-effective” meds in the second. By the way, the NICE guidelines have lots of specific suggestions on order of meds, refractory hypertension treatment, when to work-up secondary causes, special cases of when to use specific meds. It is a very long, detailed, highly referenced document, but does have much more info. The good thing about JNC-8 is it’s briefness, easy interpretation (not a lot of nuance), and less complicated algorithm.
- No information about several newer approaches, also highlighted in the european guidelines ESC and NICE, such as the use of 24-hr ambulatory or home-based monitoring to help define hypertension. Also missing in the diagnosis of hypertension is any mention of the correct method of checking blood pressure, or explicit definition of hypertension/pre-hypertension (ie, JNC-7 perhaps appropriately focused on those with either systolic>130 or diastolic>80 as prehypertensive, likely to progress to hypertension, and suggesting aggressive lifestyle changes of wt loss, exercise, DASH diet, etc). Also no mention of workup of hypertension, when to look for secondary causes, etc. There are very brief comments in the JNC-8 algorithm that lifestyle changes are important (no specific mention of wt loss, diet, exercise, salt or alcohol consumption, meds such as NSAIDs) but refers to other guidelines. I am concerned that one of the impeti (I think that is plural of impetus, from my Latin dabblings of the past) from these guidelines is to go directly to drugs (not that they say that, just that there is so minimal comment on lifestyle that it might reinforce it)
- Not sure how we mere mortals are to reconcile the different guideline suggestions. Should we not focus on diet, salt or alcohol consumption? For diabetics, should we use the new JNC-8 goal or the new American Diabetic Association goal of <140/80? Given that guidelines lead to external agencies measuring adherence to guidelines (did you do enough A1C’s on your diabetic patients?? etc), which is the right blood pressure goal for diabetics? And which of these “performance measures” will they use to rate us on our report cards?
- One issue I have commented on in past blogs is that as we base more guidelines on evidence-based medicine (and this guideline was much more evidence-based than JNC-7, which was more expert opinion), we are in the trap of not having studies that really address the question we need answered. For example, the recommendation to treat those over the ripe old age of 60 years to a higher BP goal is based on several studies which happened to choose a higher goal (eg, bring systolic down to 160 mmHg, or if already in the 160-180 range, bring it down 20 mmHg — there are no large, long-term studies stratifying older people to lower targets to see if they do better, though there was a short-term Japanese study that I sent out recently not showing any outcome difference)
Note that “this guideline was not endorsed by any federal agency or professional society prior to publication and thus is a departure from previous JNC reports” – including NHLBI. I am concerned that some of the new guidelines (eg the recent lipids one and this one) come out of specific specialty societies (who have their own issues and biases) and did not initially come out in draft form for comments (the AHRQ — agency for healthcare research and quality — always sends out drafts for public comment prior to releasing guidelines). To us guys in the trenches, the guidelines seem to have dropped down from heaven, and are rather jarring.
Geoff