For decades, doctors have been aware of a phenomenon known as “white coat hypertension” — when a patient gets higher blood pressure readings at the doctor’s office than they do at home, perhaps because they’re anxious in the clinic — but previous studies have shown inconsistencies in its effects.

Now, a large new meta-analysis confirms patients with the condition are more than twice as likely to die from a cardiac event as those whose blood pressure readings are always normal.

These same patients have a 33% increased mortality risk and are 36% more likely to experience a cardiac event like a heart attack, according to the study published Monday in Annals of Internal Medicine.

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The analysis, which pulled data from 27 studies of the condition, paints a far clearer picture of the issue than earlier, single studies did, its authors noted. The findings are also particularly important for public health efforts to address heart disease and stroke, since hypertension is a known risk factor for those events but has no known symptoms. They point, too, to the importance of accurate blood pressure monitoring that patients can take on their own, some researchers argued.

“We were very interested in just clarifying the actual risk of isolated office high blood pressure with a normal blood pressure at home,” said Dr. Jordana Cohen, the paper’s first author and an assistant professor at the University of Pennsylvania Perelman School of Medicine. “It pulls the results together to give us, sort of, a stronger sense of truly what the signal is.”

The study also distinguished between two types of patients who had abnormal blood pressure readings in the doctor’s office — some received medications to bring down their blood pressure and some did not. Those who did get medication had no increased risk for cardiovascular events or death compared to those with normal blood pressure.

Cohen said the two findings together should encourage doctors to more closely monitor patients who show white coat hypertension if they aren’t getting medication — but also that they could be overtreating people with similar readings if they receive antihypertensive medication.

“In most situations, [patients who get medication] may be more prone to side effects from the blood pressure medications or to having low blood pressure as a result of their blood pressure medications,” Cohen said.

That finding calls into question the proper treatment for white coat hypertension, she said, suggesting the importance of further studies to examine what kind of interventions might be best.

“We’re not sure if treating it with the blood pressure medication helps,” she said. “You don’t want to cause them to have low blood pressures outside of the office, since normally, their blood pressure is normal outside of the office. But we don’t know what to do about it.”

Before this meta-analysis, many previous studies didn’t distinguish between patients with these results who got medication and those who did not, according to Cohen.

The study also divided patients into further subgroups. Cohen and her colleagues found that there was also an elevated risk of cardiovascular events or mortality when the patients in the study were older, when the duration of the study was five years or longer, and when ambulatory blood pressure monitoring systems were used as opposed to home blood pressure monitoring systems, compared to patients whose blood pressure readings were always normal.

Several researchers who weren’t involved in the new paper cautioned that meta-analyses like this one often consider too many variables. Dr. Stanley Franklin, a retired University of California, Irvine, professor who has published numerous studies on white coat hypertension, also pointed out that while some of the included studies may have performed valid, robust analyses, others may not have — compromising the integrity of the meta-analysis as a whole.

Cohen argued that while that may be true in some cases, the inconsistency in the data available to them was exactly why a meta-analysis was necessary — “because you’re never going to design one single study that gets at every single one of those issues.”

She pointed out that even when different studies were excluded from the subgroup analyses, the main results remained consistent — which made the researchers “much more convinced that these findings are real.”

“When you pull all of the results of every available study together, no matter how you cut it, and if you’re very, very stringent about the quality of the studies, you still end up finding that untreated white coat hypertension is associated with this increased risk, whereas treated white coat effect [is] not,” Cohen said.

Paul Munter, who co-wrote an editorial on the study, said this was an important study because it “synthesizes the most contemporary data” and shows the importance of out-of-office blood pressure monitoring.

“Once people start blood pressure lowering medications, they’re going to be on it for the rest of their lives, and so it’s still useful to have the extra information on someone’s blood pressure before asking them to take medication for the rest of their life,” said Munter, an associate dean for research at the University of Alabama at Birmingham School of Public Health.

Cohen and others are also hoping the research will encourage insurers to cover ambulatory blood pressure monitors, in which patients wear a belt around their body, attached to a cuff on their upper arm, and which take blood pressure readings periodically. Right now, most doctors rely on home blood pressure monitoring, in which doctors entrust patients to take their own readings. That can be flawed — when patients take their own blood pressure readings, they often forget or remove measurements they don’t like from the datasets, making the data less reliable.

But ambulatory monitors are expensive, and few insurers cover them.

Dr. William White, previous president of the American Society of Hypertension, argued that the new data highlights their importance — and their relative value. Preventing cardiac events like strokes or heart attacks could save the health care system far more than the devices cost over time.

“It’s silly to not want to cover this test, because in the long run, it would pay for itself,” he said. “This [study] actually increases knowledge of how important it is to accurately diagnose people. You just need to know what they really are, because if you can’t figure that out, it’s impossible, you’re just guessing.”

For now, Cohen is recommending that those with white coat hypertension adopt a better diet and exercise, while monitoring their blood pressure out of the office regularly, with the important caveat that it is an accurate blood pressure measuring device — a list of which will come out this summer from the American Medical Association.

“There’s no such thing right now as a smartwatch, that can actually check a blood pressure without having a cuff, like an actual blood pressure cuff on it,” Cohen said. “And so it’s just very important to be a savvy consumer about these things.”

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  • My opinion is this is bc my father had the same thing he lived to be 97 died of natural causes. You shouldn’t scare people like this. Every person is different. All doctors want to do is fill you up on drugs.

  • So basically this is not something i wanted to here.Blood pressure high in doc’s office,low at home,thought it was the machine so bought 2 of them an Omron and FDA approved Contec both machines showed lower bp at home.I am 6ft 2in. and weigh 260,obese according to BMI.I guess my real question would be exactly what would happen if i stopped my bp meds,and do not forget they have found contaminents in the bp meds.Because just thinking that i have a 33% better chance of having a heart attack or stroke because my blood pressure is higher at the doctors office is flipping me out.So what is the answer,besides losing at least 50lbs somehow,and who knows still might have high bp.Is there no medium in this situation.

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  • Thanks for article and many comment which I can relate to. For years I had problem what they call “white coat syndrome”, did not matter I was at my primary doctor, dentist or any other doctor office or just having final exams. The truth, is all of that was getting worse in time of pre-menopausal time and get worse after. Never got heavy, never was raised on triglycerides, always active, but I do blame stress! Xzanaxs helped partially w heart palpitation and anxieties. That is not treatmen, only supresig bad temporary condition. Since I avoid triglyceride, allmost whole my life, the question is, why after menopause I start having high cholesterol why arterial blockages? Finally we should not forget our genetic make up.
    And after all of it, yes, 9 month ago I ended up in ER where I was told, “you’ve got heart attack” and tripple-bay pass surgery prolonged my life, for now. After surgery, still I think beside our genetic make-up and certain genoms which we inherited from all our relatives from day one, I beleive the bigest enemy is stress, internal stress which we do not recognize each time in our busy lives.

  • Im a white coat gal…every time. My doctor finishes the exam while we talk then takes my pressure again before I leave and it’s always normal…

    I just don’t like going, I get nervous.

    • Ellen. According to the research presented in this article, you should be checking your BP at home as well. Not only when you feel good either. Check it when you are feeling stressed about something too. Keep a log and report high readings to your doctor… honestly. This is the whole point of the article.

  • my question…. is thour BP up just at md office….or… has it been studied …these same people using same amount of activity to go to grocery store or some other place that requires increased activity?

  • I have gone into so many different doctors office’s and none of them read the cuff the proper way and when you get to the office you set down and wait to be called, your called finally that make you jump, next your walked into a room and jump up on the table, your feet dangling, your not setting straight or your back isn’t against something,they put the cuff on you and start it, your not relaxed, of course its going to be high (pb) after you put the cuff on and check it then wait a couple minutes and check it again you’ll see its going down, BUT THEY DON’T, oh you have high bp. But it fine at home. Whats wrong with this picture people ?

    • It appears you missed the point of the article. The point is that if your blood pressure is spiking in these situations, i.e. when you’re not completely relaxed and at rest, this meta analysis shows that you’re at increased risk of cardiac events. So, even though your BP may be fine at home, the fact that it is elevated at the doctor’s office is a problem in and of itself.

  • May I suggest. as a long time hypertensive on medication, and as a management consultant trying to devise service responses in customer facing situations…I suggest that the forced “efficiency” that propels the patient through the taking vitals the moment the patient enters the examing room promotes anxiety. The home monitor I use instructs the patient to be sitting quietly, feet on the floor prior to taking a reading. I have yet to see this happen unless I request it. These procedures. ehile possibly time saving for the staff, promotes anxiety and. I believe, skewed readings, gathered by very few white coated physicians, but mostly hurried nurses.

    • Angela,
      I understand your concerns. Any high readings on initial BP measurement should be rechecked by the practitioner who sees you… after you’ve sat for a while. If this is not done, ask for it.
      Also, refer to my initial reply to this article regarding patients with anxiety.

  • I am a PA had 2 family members with this problem. They both suffered from anxiety which complicated the issue of treating vs not treating HTN in the office. Both resisted treatment, but one finally accepted.

    My father developed MVCAD late in life at age 75 ( BP was treated). My sister developed cerebral aneurysms, suffering a devastating SAH at age 53 (BP was not treated).

    I feel HTN in the office from “white coat syndrome” should be treated if the patients also suffer from anxiety because they will have the same problem outside the office whenever they face stressors in daily life. Over the years, I feel this will add-up to a significant risk.

    • I understand totally. I’ve had this problem for 10 years and have been on anti-HTN drugs all these years. Everytime I go to a new MD, I take my home B/P readings with me and even though I was a RN for 42 years, they always appear to doubt my readings and then tend to blame me for the problem. I’ve tried every way available to ameliorate this problem including meditation, breathing exercises in the office, and, finally, Xanax prior to the appointment, none of which helped at all. I avoid all doctors as much as possible. Strangely, this never happens to me at the dentist nor the opthalmologist nor during 2 colonoscopies.

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