There's been a lot of drama in the hypertension field over the past few years. Initially sparked by the decision of the National Institutes of Health to end its sponsorship of national guidelines, the subsequent appearance of multiple guidelines with divergent recommendations led to even more controversy and discussion. Now, however, the appearance of a new scientific statement may indicate that some of the drama is dissipating, at least in one important subset of the field.
The scientific statement from the American Heart Association, the American College of Cardiology, and the American Society of Hypertension covers the important area of the treatment of hypertension in patients with existing coronary artery disease. A key element of the statement is that it is in accord with the Eighth Joint National Committee (JNC 8) guideline and reinforces the blood pressure goal of less than 140/90 mm Hg in this group of patients. “This is important since confusion has arisen in the clinical community over the last year regarding the appropriate target for blood pressure management in the general population," said Elliott Antman, President of the American Heart Association, in a press statement.
For some patients who have had a previous cardiovascular event, though, a lower target of less than 130/80 mm Hg may be considered appropriate. The statement cautions, however, against lowering blood pressure too rapidly and against lowering diastolic blood pressure below 60 mm Hg, particularly in patients over the age of 60.
Beta-blockers are a cornerstone of antihypertensive treatment in this population, though many patients may also require additional drugs. The statement also summarizes important information about the modification of additional cardiovascular risk factors, including weight loss, cholesterol control, smoking cessation, and treatments for diabetes.
Christopher O'Connor, a co-author of the statement, said in an email that the publication represents "a major effort to bring clarity and consensus for hypertension management in cardiac and vascular patients."
Responding to questions about the significance of the new statement, Antman sent a detailed outline of the AHA's perspective:
"It is important to understand the context in which this most recent statement from the AHA/ACC/ASH was generated and the gaps it is intended to fill. The present statement is an update of a 2007 statement that also focused on the management of hypertension in patients with ischemic heart disease. Thus, it focuses predominantly on the secondary prevention of events in patients with stable angina, an acute coronary syndrome, and/or heart failure of ischemic origin.
While some of these topics were on the initial list of 23 questions put forward by the group originally empaneled as JNC 8, their report was restricted to only 3 questions and the major focus was on primary prevention in the general community. This fact, coupled with their controversial recommendation calling for a relaxation of the BP target to 150/90 in persons over the age of 60 in the general population without chronic kidney disease or diabetes, has created confusion in the clinical community.
Thus, the present document emphasizes:
1. Hypertension is an important risk for fatal CAD over a wide range beginning at 115/75 for patients of all ages and each increase in systolic BP of 20 mm Hg doubles the risk of a fatal coronary event.
2. The target of < 140/90 mm Hg is reasonable for secondary prevention of cardiovascular events in patients with hypertension and CAD and an even lower target of < 130/80, which is supported by epidemiologic data, may be appropriate in some individuals.
3. As opposed to the general population, where beta-blockers are less effective in preventing myocardial infarction or stroke than other classes of antihypertensive drugs, beta-blockers should be included in the treatment of hypertension in patients with coronary artery disease because of their additional cardioprotective effects.
The AHA remains concerned about the prevalence of hypertension in this country (about 80 million adults) and its human and economic cost to our society. The secondary prevention targets in the present document provide useful guidance for the practitioner while we continue to work on our more comprehensive clinical practice guideline on hypertension. It is important to remember that hypertension exerts its harmful effects over a time horizon that is measured in decades and most RCTs do not have a long enough followup to sample the time horizon adequately (see JAMA 311: 1195, 2014). So, the upcoming comprehensive guideline will include a review of evidence both from RCTs and nonRCT sources to provide a full picture of the information that should be considered when treating a patient with hypertension. In the meanwhile, the AHA recommends a target of < 140/90 —this is especially important to reduce the risk of stroke, an important endpoint that will be a focus of the upcoming guideline."
