Why Is Out-of-Office Blood Pressure Measurement Needed?

Abstract

O ver the last decades, 2 main techniques for measuring blood pressure (BP) out of the physician's office have gained increasing importance in the clinical approach to arterial hypertension, both being supported by recent international hypertension management guidelines. 1,2 These techniques are home BP monitoring (HBPM) and 24-hour ambulatory BP monitoring (ABPM). Their diffusion in clinical practice has been favored by a number of factors, including on one side technical progress and wider availability of accurate HBPM and ABPM devices and on the other side the increasing awareness of the limitations of office BP (Table 1). 3,4 Office BP is in fact characterized by a random error affecting casual BP readings and by a systematic error related to the patient's alerting reaction to the measurement procedure and setting, known as "white coat effect." 1,3 Both ABPM and HBPM are devoid of these limitations and, thus, provide more stable and reproducible information on BP values, 5 which is also of greater prognostic relevance 6 -21 (Table 2). Furthermore, office BP readings are unable to collect information on BP during a subject's usual activities and over a long period of time, 22 an important limitation in everyday management of hypertensive subjects that can be overcome by out-of-office BP monitoring.ABPM was initially confined to specialized hypertension centers because of its relatively high cost, but over the years its availability has steadily increased. HBPM, on the other hand, has been used rather reluctantly by physicians in routine management of hypertensive patients. Although its potential usefulness in clinical practice was acknowledged many years ago, 23 its application has been limited until the end of last century by the need to use auscultatory measurements, an approach that is difficult to apply correctly, 24 particularly in the home setting, and prone to providing inaccurate information, especially when using aneroid devices. 25 A major breakthrough came with the introduction of inexpensive, easy-to-use, and accurate automated oscillometric BP measuring devices, leading to a widespread use of HBPM. At present, in developed countries Ϸ70% of hypertensive patients regularly assess their BP at home, 26,27 and the clinical usefulness of this approach is generally acknowledged by physicians. 28,29 Such a rapidly growing diffusion of HBPM in clinical practice has inevitably raised the question of whether HBPM

Response to Home Blood Pressure Measurements Will or Will Not Replace 24-Hour Ambulatory Blood Pressure Measurement

“…2,3 We largely agree with O'Brien's 1 observations, although with a slightly different perspective.First, we agree that isolated HBP measurements are of limited clinical value. Indeed, only the average of repeated HBP readings carries diagnostic and prognostic information, which may be partly comparable to that provided by 24-hour ABPM, 4 with most outcome studies being based on structured HBPM schedules including a consistent number of measurements.…”

“…3 A wider availability of ABPM might allow this diagnostic tool to become a more frequent companion to the HBPM implementation in daily practice, complementing the information that it provides. Indeed, whereas HBPM allows BP to be measured over a relative long time span, ABPM provides unique assessment of the 24-hour ABP profile, including nighttime and morning BP and BP variability.…”

Self blood pressure monitoring: a worthy substitute for ambulatory blood pressure?

“…At present, there is a debate over the exact place for ambulatory and self monitoring. 30,31 However, there is consensus that self monitoring does provide a cheap and patient friendly method of BP monitoring in the management of hypertension. The ESH described a schedule of self-monitoring, 18 which was somewhat pragmatic but until now has lacked any real evidence.…”

European Society of Hypertension Practice Guidelines for home blood pressure monitoring

“…Its use is also recommended for the identification of patients with suspected white-coat or masked hypertension, (particularly among subjects with borderline or highly variable office BP, high cardiovascular risk and normal office BP, hypotension symptoms in spite of inadequate office BP control by treatment, no signs of organ damage in spite of the high office BP). 23,25,26 HBPM is further recommended in patients with poor compliance with treatment (HBPM may increase their involvement in hypertension management), and possibly also in some high-risk populations in whom close BP control is mandatory (pregnant women, renal and diabetic patients). In pregnancy, HBPM should be performed with devices validated in this condition and available evidence suggests that the diagnostic thresholds should be the same as in the general population, although more studies are needed on this issue.…”