Chicago, IL—The long-awaited update of the hypertension treatment guidelines, the Eighth Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (JNC-8), will be published at the end of 2012. The previous guidelines (JNC-7) were last published in 2003.
Suzanne Oparil, MD, Professor, Department of Medicine, Division of Cardiovascular Disease, University of Alabama, Birmingham, and cochair of the expert panel that developed these guidelines, discussed the process that has contributed to the lengthy delay in publishing the JNC-8 guidelines at the 2012 American College of Cardiology (ACC) meeting.
The new JNC-8 hypertension guidelines will answer 3 clinical questions:
- When to initiate drug treatment?
- How low should blood pressure (BP) be lowered?
- How do you get there?
These questions were defined to answer whether health outcomes in patients with hypertension are improved by initiating antihypertensive pharmacologic therapy at specific BP thresholds, by reaching specific BP goals, and by using different antihypertensive drugs or classes of drugs that differ in comparative benefits and harms. Dr Oparil gave no indication of what the specific recommendations will be.
The development of the JNC-8 clinical practice guidelines is part of the current National Heart, Lung, and Blood Institute (NHLBI)-sponsored adult cardiovascular disease (CVD) prevention guidelines program. The Adult Treatment Panel guidelines for the treatment of elevated blood cholesterol and the overweight and obesity guidelines are being developed simultaneously. Ultimately, these 3 guidelines will be integrated into 1 CVD risk-reduction guideline.
Ensuring that the JNC-8 guidelines are firmly evidence-based is the reason that it has taken so long to write them, said Dr Oparil. This intensified focus is a direct result of an Institute of Medicine (IOM) report published in 2001 about the quality chasm, which noted that clinical decision-making is based on training and experience.
The report also advocated patient care based on the best-available scientific knowledge and the elimination of variability in healthcare.
Dr Oparil noted that only 3 of the ACC/American Heart Association guidelines have the top level of evidence (level A) for >20% of the recommendations in the guideline; the others range from 15% to 55%.
The new NHLBI-sponsored adult cardiovascular guidelines, including JNC-8, will not look like the previous guidelines, Dr Oparil pointed out. They will be strictly evidence-based, have more depth and rigor, be more focused, and use evidence-based strategies for their implementation, she explained.
The practice guidelines will include a summary of the evidence for each clinical question, graded evidence statements, graded recommendations, and references.
Increased Focus on Level of Evidence
A process for developing the guidelines was established to “ensure the rigor and to minimize bias,” said Dr Oparil, and it uses methods to meet many of the new IOM standards for systematic reviews. Strict criteria were established for the systematic literature search, rating the study quality with instruments for different studies, and for data abstraction and developing evidence tables.
The quality of the evidence is rated as low, moderate, and high. The strength of a recommendation will range from A for strong evidence, B for moderate, C for weak, D for against, E for expert opinion, and N for no recommendation.
There is wide representation of expertise on the JNC-8 expert panel, ranging from hypertension, primary care, cardiology, nephrology, research methodology, evidence-based medicine, epidemiology, and guideline development and implementation, among others.
The rationale for the clinical questions driving the JNC-8 guidelines is to assess the evidence for BP level of 140/90 mm Hg as a treatment goal; to determine if this treatment threshold should be adjusted for specific disease conditions, comorbidities, characteristics, or age; and to determine whether there is evidence of improved outcomes by lowering BP with a particular drug or drug class.
The JNC-8 guidelines will provide practice guidance for patients aged ≥18 years across a number of prespecified subgroups, such as diabetes, chronic kidney disease, CVD, older adults, sex, racial and ethnic groups, and smokers.