Old guidelines still appropriate for blood-pressure targets

Despite recently published hypertension guidelines that recommend a new target for blood pressure (BP) lowering in individuals starting at age 60, it is still appropriate to continue to focus on BP targets set by an older guideline as recommended by the American Heart Association (AHA) and the American College of Cardiology (ACC).

Until more definitive information is known on the risk of lowering BP targets, it is “appropriate to continue to focus on increasing the number of hypertensives controlled to<140/90 mmHg in most adults younger than 80 years of age,” according to Jackson T. Wright, Jr., MD, PhD, Professor of Medicine at Case Western Reserve University and Director of the Clinical Hypertension Program at the University Hospitals Case Medical Center in Cleveland, OH, who discussed the new guidelines in a session called “Blood Pressure Targets: What’s Age Got to Do With It.”

It is known that age is a powerful risk factor for hypertension complications, particularly in African Americans and other high risk groups, with data showing substantially higher cardiovascular deaths in persons 65 years and older compared to persons below this age.

Reducing BP dramatically reduces the complications of hypertension, with current recommendations of BP of <140/90 mm Hg as the target to achieve to reduce complications in adults less than 80 years of age. However, as Wright noted, the recently published 2014 JNC 8 Evidence-Based Guideline for the Management of High Blood Pressure in Adults has altered the recommendation to achieving a target goal of <150/90 mm Hg in adults starting at age 60.

Wright emphasized that the 2014 guideline is currently the only hypertension guideline in the world to recommend easing up on BP control in patients as young as 60 years of age.

“There is no evidence of a benefit and clear risk of harm if recommended blood pressure targets are raised to greater than 150/90 mm Hg at this time,” he said, particularly in African Americans and other high risk groups.

He emphasized that more definitive information on the risk benefit of lowering BP targets is needed, and said this should be forthcoming in the Systolic BP Intervention Trial (SPRINT).

Commentary by William Elliott, MD, Professor of Preventive Medicine, Internal Medicine and Pharmacology, Head, Division of Pharmacology, Chairman, Department of Biomedical Sciences, Pacific Northwest University of Health Sciences, Yakima, WA

Dr. Wright and his colleagues, who were appointed to JNC 8, were restrained by NIH policies to use only data derived from primary outcomes of high-quality randomized clinical trials in populations representative of the US to form answers to the three questions that they considered. But it turns out that there are no trials that randomized subjects to different systolic blood pressure targets that found significant differences in cardiovascular or renal events. Therefore, the decision to recommend a systolic blood pressure of 150 mm Hg could have been made for patients of all ages, not just those older than 80 or 60 years.

The target systolic blood pressure of 150 mm Hg was recommended by Hypertension in the Very Elderly Trial (HYVET), but this trial compared active drug(s) versus placebo, not one blood pressure level with another. Despite the absence of data from clinical trials, and a plethora of data from cohort studies, population surveys, and “lower forms of evidence,” the panel declared that, for patients between 18 and 59 years of age, the most appropriate systolic target was 140 mm Hg (based on “Expert Opinion”), whereas it was 150 mm Hg for people over age 60 years (again based only on “Expert Opinion”). It will be a great pity if we have to wait until December 2018 (when the SPRINT trial is expected to be completed) to learn that lower systolic blood pressures nearly always reduce stroke rates, as seen in many trials. The fact that stroke deaths fell in 2013 to the 5th leading cause of death in the US (falling from 4th in 2005-12, 3rd from 1954-2004, and 2nd from 1918-53) is likely related to the fact that blood pressure control rates in the US adult population (based on NHANES 2001-12) have steadily improved in the last 12 years.

As others have pointed out, the groups who are at greatest risk for stroke and other preventable complications of poorly controlled hypertension are older Americans, blacks, women, diabetics, and those with chronic kidney disease. In their most recent guidelines, both the American Diabetes Association and National Kidney Foundation have “suggested” (a weaker term than “recommended”) that the older target blood pressures for diabetics or people with chronic kidney disease (< 130/80 mm Hg) may still be appropriate, especially if it is easy to attain and well-tolerated. Others have argued that excessive prescription of antihypertensive agents costs money, causes adverse effects (including fractures and falls), increases costly medical office and Emergency Department visits, and is an inconvenience at best, and a clear risk to life, limb, and the national debt at worst. A recent cost-effectiveness calculation concluded that full implementation of the JNC 8 guidelines, despite their relaxed blood pressure targets, would prevent 56,000 cardiovascular events, 13,000 deaths, and be cost-saving overall. What they didn’t calculate, however, was the potential impact of treating today’s patients to blood pressure targets as previously recommended, even if those targets are not fully evidence-based.