SNOWMASS, COLO. – The redefinition of hypertension as 130/80 mm Hg or higher introduced in the current American College of Cardiology/American Heart Association hypertension management guidelines has generated considerable controversy. Often overlooked, however, has been another major innovation included in the 2017 guidelines: the rise in the status of out-of-office 24-hour ambulatory blood pressure monitoring and home blood pressure self-measurement to a class I, level of evidence A recommendation, , observed at the annual Cardiovascular Conference at Snowmass sponsored by the American College of Cardiology.
It’s a guideline he strongly endorses.
“We do a lot of this. It can be a challenge to get 24-hour ambulatory blood pressure monitoring covered by payers, sosaid Dr. Kates, professor of medicine and director of the cardiology fellowship program at Washington University, St. Louis.
He explained that one of the four key questions the guideline committee was tasked with answering at the outset of deliberations was this: What’s the evidence base for self-directed out-of-office blood pressure monitoring? Based on the panel’s systematic review of the literature, this practice wound up receiving the strongest possible class Ia recommendation, specifically for confirming the diagnosis of hypertension and for titration of antihypertensive medications. Moreover, the guidelines also endorsed home blood pressure monitoring for the detection of white-coat hypertension, this time as a Class IIa recommendation, as well as for identification of patients with masked hypertension, with class IIb status ().
The 2017 ACC/AHA guidelines include a detailed checklist for obtaining accurate measurements of office blood pressure. The suggestions include having the patient sit relaxed in a chair with both feet on the floor for at least 5 minutes before taking the measurement, no coffee or exercise for 30 minutes beforehand, empty the bladder, no talking, no clothing over the arm, and other recommendations. Many busy clinicians roll their eyes at the impracticality of doing all this on a routine basis.
“I don’t want to take an audience survey, but I’ll say that even in our office we are not successful in doing this. Patients run up the stairs to the office after dealing with traffic and the parking garage, they’re late for their appointment, in winter they’re wearing a sweater and don’t want to take it off. These are things we don’t do well, and they’re low-hanging fruit where we could do better,” Dr. Kates commented.
The challenges inherent in performing by-the-book office blood pressure measurement reinforce the importance of home self-monitoring of blood pressure in what is hopefully a more stress-free environment.
“We can give patients specific guidance about checking their blood pressure an hour after taking their medications, sitting for 5 minutes, and checking the pressures on a bare arm and not with the sleeve rolled up,” he noted.
The guidelines recommend using home blood pressure monitoring or ambulatory monitoring to detect white-coat hypertension in patients with an office blood pressure of 130/80 mm Hg or more, but less than 160/100 mm Hg, after a 3-month trial of lifestyle modification. If the home blood pressure is less than 130/80 mm Hg, that’s evidence of white-coat hypertension, for which the recommended treatment consists of continued lifestyle modification plus periodic monitoring of out-of-office blood pressures in order to promptly detect progression to hypertension. If, however, the out-of-office blood pressure is not less than 130/80 mm Hg, that’s hypertension, and the guidelines recommend starting dual-agent antihypertensive drug therapy while continuing lifestyle modification.
A confusing array of definitions of hypertension are now in use by various medical societies. While the 2017 ACC/AHA hypertension guidelines define hypertension as office blood pressure of 130/80 mm Hg or more, the 2018 European Society of Cardiology/European Society of Hypertension guidelines use a threshold of 140/90 mm Hg or more. Joint American Academy of Family Physicians/American College of Physicians guidelines recommend a treatment target of less than 150 mm Hg in hypertensive patients aged 60 years or older. And at the other end of the spectrum, the SPRINT trial showed a significant cardiovascular benefit for intensive treatment of hypertension to a target systolic blood pressure below 120 mm Hg, rather than less than 140 mm Hg ().
Dr. Kates believes the debate over the “right” treatment target misses the central point, which is that hypertension is staggeringly undertreated. Indeed, the Centers for Disease Control and Prevention estimates only one in four adults with hypertension have their disease under control. That’s a disconcerting statistic given that hypertension accounts for more cardiovascular deaths than any other modifiable cardiovascular risk factor.
“There’s been some concern raised that maybe too much weight has been put on the SPRINT trial in making the ACC/AHA recommendations, but I think it’s helpful to understand that we vastly undertreat patients with hypertension. So I think that, rather than being so concerned that we’re going to be treating people to too low a target or we’re being overly aggressive, it should give us some pause to think about the fact that we’re ordinarily not being aggressive enough with many of our patients as it is,” the cardiologist said.
Dr. Kates reported having no financial conflicts regarding his presentation.