By Harold L. Karpman, MD, FACC, FACP
Clinical Professor of Medicine, UCLA School of Medicine
Dr. Karpman reports no financial relationships relevant to this field of study.
SYNOPSIS: Analysis from the Dallas Heart Study consisting of 3027 adults revealed that both white-coat hypertension and masked hypertension were independently associated with increased cardiovascular events, and, therefore, home blood pressure monitoring is recommended for U.S. adults, whether symptomatic or asymptomatic.
SOURCE: Tientcheu D, et al. Target organ complications and cardiovascular events associated with masked hypertension and white-coat hypertension. Analysis from the Dallas heart study. J Am Coll Cardiol 2015;66:2160-2169.
Since blood pressure (BP) readings are affected by so many factors (i.e., anxiety, body position, activities, etc.), it has been widely recognized that the office BP may not accurately reflect BPs obtained in the out of office environment.1-3 The pattern of discordance between home and office BP readings can be divided into two major categories: white-coat hypertension (WCH), which is defined as an elevated office BP reading with normal ambulatory or home BP, or masked hypertension (MH), which is an elevated ambulatory or home BP associated with a normal office BP.4 The cardiovascular (CV) prognosis of WCH has been controversial, even though some published studies have revealed increased target organ damage and CV complications in patients with WCH.5-7 Other studies have revealed no significant anatomical or prognostic differences when patients with WCH were compared with a normotensive population.8,9
Because of the published uncertainties regarding the clinical and anatomical effects of MH and WCH, Tientcheu et al evaluated the extent of target organ complications and CV prognosis associated with MH and WCH in 3027 participants of the Dallas Heart Study who were followed for 9 years.10 The Dallas Heart Study is a multiethnic, probability-based population sample of Dallas County adult residents. The study began in the year 2000 and, when evaluated, its population consisted of 54% African-Americans and 49% women, with a median age of 43 years. The same automatic oscillometric BP device was used during the in-home visits and in the office. The average of the third to the fifth BP values measured at home was recorded and used as the encounter BP both in the office and at home. Participants with WCH (3.3% of the sample) and MH (17.8% of the sample) were found to have an increased aortic pulsed wave velocity, cystatin C, and urinary albumin-to-creatinine ratio, and they were independently associated with higher CV events when compared with a normotensive group, even after adjusting for traditional CV risk factors.
COMMENTARY
One of the striking observations noted in this study was the significant frequency of MH occurring in 17.8% of participants overall and in 14% of those not receiving antihypertensive therapy. Whereas WCH, which occurred in 3% of the group, has been proposed to be secondary to stress-induced activation of the sympathetic nervous system during encounters with healthcare providers,11 MH is potentially induced by mental stress at home, excessive consumption of alcohol or caffeine and/or cigarette smoking, although many other lifestyle factors may contribute to the frequency of MH.12 The important findings demonstrating increased CV risk occurring in patients with both MH and WCH independent of CV risk factors and antihypertensive drug therapy confirms the findings of many previously published studies: Hypertension should be controlled with drug therapy, not only in the office but also in the outpatient environment. Patients must learn to properly monitor their BP at home and partner with their physician to obtain appropriate and adequate antihypertensive drug therapy and counseling as required.
In summary, clinicians should be aware that office BP readings do not provide a complete picture of a patient’s BP profile because MH is so common and associated with adverse cardiovascular findings. Obviously, more research is needed in this important area. For now, consider performing home BP monitoring routinely for all adults to uncover MH patients who may require drug therapy to prevent long-term CV damage.
REFERENCES
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