New Hypertension Guidelines Will Be Strictly Evidence-Based

Value-Based Care in Cardiometabolic Health Dec 2012, Vol 1, No 3
Wayne Kuznar

Boston, MA—Expect new national guidelines for the management of hypertension (HTN) to back away from recommending a target blood pressure (BP) of <130/80 mm Hg in patients with diabetes and/or chronic kidney disease (CKD), according to George Bakris, MD, Professor of Medicine at the University of Chicago and Director of the Comprehensive Hypertension Center, Chicago, IL, who discussed the new guidelines at the 2012 Cardio­metabolic Congress.

Although nearly all current HTN guidelines recommend <130/80 mm Hg as a target in patients with diabetes or CKD to reduce the risk for cardiovascular (CV) events and slow the progression of nephropathy, there is no evidence to support this recommendation, he said.

The update to JNC-7 (Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure) guidelines that were issued nearly a decade ago has been anticipated for some time. The initial recommendations will address 3 main questions:

  • Does initiating antihypertensive drug therapy at specific BP thresholds improve outcomes in adults with HTN?
  • Does treatment with antihypertensives to a specified BP goal lead to improved outcomes in adults?
  • In adults with HTN, do various antihypertensive drugs or drug classes differ in comparative benefits and harms on specific health outcomes?

Of 16 current clinical practice guidelines for the prevention of CV disease with level of evidence recommendations, only 9% had class I level A evidence to support statements made in the guidelines. “The rest of it was ‘professional opinion’ or ‘some evidence,’” said Dr Bakris.

The methods used for the new guidelines meet many of the new Institute of Medicine standards for systematic reviews. The guidelines will be strictly evidence-based, focusing on randomized controlled clinical trials, and will grade evidence statements. Meta-analyses will not be part of the evidence base.

Evidence quality will range from high (well-designed and conducted randomized controlled trials [RCTs]) to low (RCTs with limitations; observational studies with major limitations), and recommendation strength will be strong (A), moderate (B), weak (C), against (D), expert opinion (E), or no recommendation (N).

“The new guidelines are going to be truly different from what you’re used to seeing,” Dr Bakris noted. “There will be a statement, and then there will be references to defend the statement.”

For initial therapy, “We can probably get by with a single agent for patients with blood pressure <160/100 mm Hg if they adhere to lifestyle recommendations. If they don’t, you’re going to need 2 or 3 agents,” said Dr Bakris. “Even in the ALLHAT [Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack] study of patients with stage 1 hypertension, the average number of drugs required to achieve goal blood pressure was 2.1.”

He continued, “As initial therapy, don’t be afraid to start with combinations. If the patient is at >160/100 mm Hg, you need to start with combination therapy, and you have a panoply of combination therapies to pick from.”

In Diabetes, No Support for <130/80 mm Hg
Another near-universal recommendation is the target of <130/80 mm Hg in patients with CKD and/or diabetes, “but the evidence does not support <130/80 mm Hg if you carefully look at it,” Dr Bakris said.

The ACCORD (Action to Control Cardiovascular Risk in Diabetes) trial failed to support a systolic BP (SBP) target of <120 mm Hg compared with <140 mm Hg with the primary composite outcome of nonfatal myocardial infarction, nonfatal stroke, and CV death. CV outcomes from the diabetes subgroup in the International Verapamil SR-Trandolapril trial also failed to show better outcomes in patients randomized to a goal SBP of <130 mm Hg compared with a goal SBP of 130 to 140 mm Hg.

“Clearly, there’s no good evidence to support <130 mm Hg. There’s a trunkload of evidence to support <140 mm Hg,” Dr Bakris advised.

Lower Targets Not Beneficial in CKD
Three RCTs of BP targets in patients with CKD, which included a total of 2272 participants, have been conducted. “All failed to show a benefit of the lower level of blood pressure,” said Dr Bakris. None of these trials enrolled patients with diabetic nephropathy, so the optimal goal BP in this group is unknown, he added.

Finally, an examination of the Kidney Early Evaluation Program, a screening program of >16,000 persons at high risk of kidney disease started by the National Kidney Foundation, found no benefit to an SBP goal of <130 mm Hg in postponing dialysis for a mean follow-up of 2.8 years, and a diastolic BP of <60 mm Hg was associated with faster progression to end- stage renal disease.

<150/80 mm Hg Goal in the Elderly
In the elderly, the goal BP in patients with uncomplicated HTN generally has been <140/90 mm Hg, but an SBP goal of 140 to 145 mm Hg is deemed acceptable. This target for elderly patients with HTN, however, is based on expert opinion rather than data from RCTs, which supports a goal of <150/80 mm Hg, concluded Dr Bakris. “It is unclear if target SBP should be the same in 65 to 79 year olds as in patients older than 80 years,” he said.

Last modified: January 24, 2013
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