Patients with untreated ‘white coat’ hypertension twice as likely to die from heart disease

It’s a fairly common scenario.
 
You take a patient’s blood pressure and it’s high.
 
‘I always have high blood pressure when I’m at the doctor,’ the patient says.
 
You give them time to rest before taking another reading.
 
It used to be considered that patients whose blood pressure went up in a doctor’s room were experiencing ‘white coat’ syndrome in response to issues such as anxiety. Such readings were not necessarily seen to be indicative of a patient’s usual blood pressure readings, nor of subsequent risks to their health.
 
However, growing bodies of research continue to point towards the more sinister effects of white coat hypertension.
 
A new systematic review and meta-analysis, published in the Annals of Internal Medicine, found that patients with untreated white coat hypertension not only have a heightened risk of heart disease, but are twice as likely to die from heart disease compared to those with normal blood pressure.
 
Meanwhile, patients with white coat hypertension who were taking antihypertensives did not have an increased risk of heart disease or cardiovascular-related death compared to those with normal blood pressure readings.
 
‘Studies suggest that about one in five adults may have white coat hypertension. Our findings underscore the importance of identifying people with this condition,’ lead study author Jordana  Cohen, Assistant Professor in the Division of Renal-Electrolyte and Hypertension and Senior Scholar in the Center for Clinical Epidemiology and Biostatistics, said.
 
‘We believe individuals with isolated in-office hypertension – those who are not taking blood pressure medication – should be closely monitored for transition to sustained hypertension, or elevated blood pressure both at home and the doctor’s office.’
 
For this paper, the researchers conducted a meta-analysis of 27 studies, comprising more than 60,000 patients with untreated white coat hypertension or treated white coat effect.
 
Compared with normotensive patients, those with untreated white coat hypertension had a 36% increased risk of heart disease, 33% increased risk of death and 109% increased risk of death from heart disease.
 
‘Our findings support the pressing need for increased out-of-office blood pressure monitoring nationwide, as it’s critical in the diagnosis and management of hypertension,’ Assistant Professor Cohen said.
 
‘Simultaneously, we advise individuals with untreated white coat hypertension to engage in lifestyle modifications, including smoking cessation, reduction in their alcohol intake, and making improvements to their diet and exercise regimens.
 
‘We also caution providers not to over-treat individuals with white coat hypertension who are already on blood pressure medication, as this could lead to dangerously low blood pressures outside of the office and unnecessary side effects from medication.’
 
Finding the balance between correctly identifying hypertension, not under-diagnosing or over-diagnosing it, nor under-treating or over-treating it, can be challenging.
 
This is not the first paper to point to the potentially harmful effects of white coat syndrome.
 
A paper published last year in the Korean Circulation Journal concluded that white coat hypertension is ‘by no means clinically innocent’ because of its frequent association with metabolic abnormalities, sub-clinical organ damage and a risk of cardiovascular events that is higher than in truly normotensive individuals.
 
‘At present, the identification of the fraction of high-risk [white coat hypertension] subjects seems to be a key step in the selection of appropriate therapeutic strategies, including antihypertensive therapy,’ the authors stated.
 
‘Ambulatory monitoring may be the most effective method for diagnosing and confirming whether patients are persistently hypertensive or experiencing white coat syndrome.’
 
That paper went on to say that ambulatory monitoring should be used to confirm the diagnosis of white coat hypertension within three months, and every six months thereafter, as well as to provide continued monitoring of these patients, as there is a risk of developing true hypertension.
 
This ties in with the RACGP’s Guidelines for preventive activities in general practice (Red Book) recommendations.
 
The Red Book states that ambulatory blood pressure monitoring or self-measurement should be used, if possible, for patients with suspected white coat hypertension.
 
A 2013 article in Australian Family Physician also recommended, ‘Patients with a diagnosis of white coat hypertension will require confirmation of the diagnosis by repeat ambulatory monitoring within six months, continued surveillance by repeating ambulatory monitoring every 1–2 years, and ongoing lifestyle modification’.
 
The prevalence of white coat hypertension has not been consistent across studies, though previous research suggests an overall prevalence of 13%.
 
In 2014–15, close to six million Australians aged 18 and older had high blood pressure, according to the Heart Foundation. Of these, more than two-thirds (68%) had uncontrolled or unmanaged high blood pressure.

blood pressure hypertension white coat syndrome