Untreated white-coat hypertension associated with increased cardiovascular and mortality risk

An accompanying editorial suggested that out-of-office blood pressure monitoring be used to distinguish between white-coat hypertension and sustained hypertension in patients with high blood pressure measurements in the office.

Untreated white-coat hypertension, but not treated white-coat effect, was associated with an increased risk for cardiovascular events and all-cause mortality, according to a systematic review and meta-analysis.

Researchers reviewed studies that evaluated the association of white-coat hypertension with cardiovascular events and mortality. Twenty-seven observational studies with at least three years of follow-up were included. They evaluated 25,786 participants with untreated white-coat hypertension or treated white coat effect and 38,487 participants with normal blood pressure followed for a mean of 3 to 19 years. Results were published June 11 by Annals of Internal Medicine.

Compared with normotension, untreated white-coat hypertension was associated with an increased risk for cardiovascular events (hazard ratio [HR], 1.36; 95% CI, 1.03 to 2.00), all-cause mortality (HR, 1.33; 95% CI, 1.07 to 1.67), and cardiovascular mortality (HR, 2.09; 95% CI, 1.23 to 4.48). The risk of white-coat hypertension was attenuated in studies that included stroke in the definition of cardiovascular events (HR, 1.26; 95% CI, 1.00 to 1.54). No significant association was found between treated white-coat effect and cardiovascular events (HR, 1.12; 95% CI, 0.91 to 1.39), all-cause mortality (HR, 1.11; 95% CI, 0.89 to 1.46), or cardiovascular mortality (HR, 1.04; 95% CI, 0.65 to 1.66).

The study authors wrote that the elevated risk associated with white-coat hypertension was particularly evident in studies that used ambulatory blood pressure monitoring (not home self-monitoring) and studies with at least five years of follow-up time. According to the researchers, these findings suggest that individuals with isolated office hypertension who are not receiving antihypertensive treatment should be closely monitored, while individuals who are receiving antihypertensive treatment could be harmed by overly aggressive management. They added that out-of-office blood pressure monitoring is critical in the diagnosis and management of hypertension.

An editorial noted, “For adults taking antihypertensive medication, the results are clear. White coat effect is not associated with increased risk, and out-of-office monitoring seems warranted to prevent intensification of antihypertensive treatment. For adults not taking antihypertensive medication, the risk for CVD [cardiovascular disease] events and all-cause mortality is only moderately increased, and this risk is substantially lower than that associated with sustained hypertension. Therefore, out-of-office BP [blood pressure] monitoring is useful for distinguishing between [white coat hypertension] and sustained hypertension among persons with high office BP.”