April 6th, 2015
Bringing Clarity and Consensus to the Treatment of Hypertension in Patients with CAD
Elliott Antman, MD
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.
I believe that we should reduce blood pressure in secondary prevention further than 140/90 as long as we do not reduce the diastolic blood pressure so low that the heart gets inadequate perfusion. I try to get the plaque rupturing systolic blood pressure as low as I can get it as long as the myocardial perfusion diastolic remains above 60 mm Hg.
Beta blockers have been shown to improve outcomes for 1 year after an acute MI. After that, there appears to be no special value in this class of drug. To use beta blockers in subjects with CAD who are not within the first year after MI is not an evidence based recommendation. Considering the added value of ACE/ARB drugs, combined with the risk for diabetes and side effects on beta blockers, I feel this recommendation should be reviewed.
I much prefer the ACC/AHA recommendations as opposed to the JNC 8 guidelines. It we look back to MRFIT we can see that cardiovascular disease is even increased at our so called normal blood pressures of 120/80. So in my book lower is better and I like under 140/90 or under 130/85 for some patients.
Yes lower is better, but the answer that still eludes us is how low can we go safely in pts with cornoary artery disease. In other words, at what blood pressure lowering do the risks outweigh the benefits. I don’t believe we have the answer to that question.
Edward C Horwitz DO, FACC, FACP
Senior Cardiologist MALRAM
Iscilov Hospital/ Tel Aviv Medical Center
COL MED USAR
In newly diagnosed Type 2 diabetics, getting the BP to < 110/75 mm of Hg , had excess risk for mortality at 3.5 years (Vamos et al, BMJ 2012 Aug 30);So, the lower the better no longer holds true !
I do believe that “blood pressure” is a moving target with a fair amount of daily variability. Prescriptions done on the basis of the occasional office visit are problematic.
I do believe that in the general, as well as the high risk population, rational treatment of blood pressure should utilize home blood pressure monitors which have been calibrated or confirmed to be accurate with blood pressures checked in the office.
Home blood pressure cuffs are relatively inexpensive ($30 – $50) on line and generally quite accurate.