Untreated White-Coat Hypertension Tied to CV Events, Mortality

Megan Brooks

June 18, 2019

Patients with untreated white-coat hypertension (WCH) are at increased risk for cardiovascular (CV) events and all-cause mortality compared with those with treated white-coat effect (WCE), results of a large review and meta-analysis of published studies suggest.

"The findings underscore the importance of encouraging our patients to monitor their blood pressures outside of the office, and for us to integrate out-of-office blood pressure readings as an important part of our care plan for each patient," Jordana B. Cohen, MD, assistant professor of medicine and epidemiology, University of Pennsylvania Perelman School of Medicine, Philadelphia, told theheart.org | Medscape Cardiology.

"I think that a lot of providers are still skeptical of the utility of out-of-office blood pressure monitoring, and I hope that the results of this study, in combination with Daichi Shimbo and Paul Muntner's editorial and other important studies in the past few years, help to dispel such misgivings," said Cohen.

The study and editorial were published online June 10 in the Annals of Internal Medicine.

The long-term CV risk for isolated elevated office blood pressure (BP) is unclear. Cohen and her colleagues assessed the risk for CV events and all-cause mortality associated with untreated WCH, which refers to elevated in-office but normal out-of-office BP, and treated WCE, which is WCH in those on antihypertensive treatment.

Their review and meta-analysis involved 27 studies with a total of 25,786 participants with untreated WCH or treated WCE and 38,487 with normal BP followed for an average of 3 to 19 years.

Compared with normal BP, untreated WCH was associated with an increased risk for CV events, all-cause mortality, and CV mortality. No significant association was found between treated WCE and these outcomes. The findings persisted across several sensitivity analyses.

Outcome Risk With WCH and WCE
Outcome WCH (95% CI) WCE (95% CI)
CV events 1.36 (1.03–2.00) 1.12 (0.91–1.39)
All-cause mortality 1.33 (1.07–1.67) 1.11 (0.89–1.46)
CV mortality 2.09 (1.23–4.48) 1.04 (0.65–1.66)

Those with untreated WCH "need to be closely monitored with out-of-office blood pressure monitoring for transition to sustained hypertension," Cohen told theheart.org | Medscape Cardiology. "These individuals are at a higher risk of developing sustained hypertension compared with individuals with normotension, and this often uncaptured transition to sustained hypertension likely drives the increased risk of heart disease and death."

Future studies, she added, are needed to assess whether actively initiating treatment in patients who have untreated WCH helps to reduce CV risk.

"To the best of my knowledge, there is no evidence for initiating treatment in untreated WCH at this time; treating WCH could potentially put individuals at risk of low blood pressures out of the office and unnecessary side effects. Alternatively, we encourage out-of-office monitoring for transition to sustained hypertension," said Cohen.

For individuals with treated WCE, "we need to be cautious not to overtreat them, as they may be prone to out-of-office hypotension and unnecessary side effects from medications," said Cohen.

"Important" Study Supports Existing Guidance

In their editorial, Daichii Shimbo, MD, Columbia University Medical Center, New York City, and Paul Muntner, PhD, University of Alabama at Birmingham, say this meta-analysis has several strengths.

"The literature search was comprehensive and included several recently published studies, it included only studies that adjusted for potential confounders, and analyses were performed demonstrating that the results were not highly influenced by any one study," they point out.

They note that although they were largely consistent in most subgroup analyses, the association between WCH and risk for CV events was seen only in studies in which the average age of participants was at least 55 years and in those that included individuals with a history of cardiovascular disease (CVD), chronic kidney disease, or diabetes.

"Therefore, the increased CVD risk associated with WCH may be present only among older persons who have high CVD risk," Shimbo and Muntner write.

"Overall, the meta-analysis by Cohen and colleagues makes an important contribution and provides contemporary data supporting recent US and European guidelines that recommend out-of-office BP monitoring to screen for WCH and WCE," they conclude.

The study was supported by a grant from the National Institutes of Health. Cohen, Shimbo, and Muntner have no relevant financial disclosures.

Ann Intern Med. Published online June 10, 2019. Abstract, Editorial


Comments on Medscape are moderated and should be professional in tone and on topic. You must declare any conflicts of interest related to your comments and responses. Please see our Commenting Guide for further information. We reserve the right to remove posts at our sole discretion.