April 6th, 2015
Bringing Clarity and Consensus to the Treatment of Hypertension in Patients with CAD
CardioExchange invited Elliot Antman, President of the American Heart Association (AHA), to discuss the recently released scientific statement from the AHA, the American College of Cardiology (ACC), and the American Society of Hypertension (ASH) on the treatment of hypertension in patients with existing coronary artery disease (CAD). Our news coverage of the statement can be found here.
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 AHA 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 three 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 blood pressure (BP) target to 150/90 mm/Hg in those 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 mm/Hg 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 mm/Hg, 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 CAD because of their additional cardioprotective effects.
The AHA remains concerned about the prevalence of hypertension in this country (affecting 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 randomized, controlled trials (RCTs) do not have a long enough follow up to sample the time horizon adequately (see JAMA 311: 1195, 2014). Therefore, 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 BP target of < 140/90 mm/Hg — this is especially important to reduce the risk of stroke, an important endpoint that will be a focus of the upcoming guideline.