Serial Automated Office BP Tackles White-Coat Hypertension

March 18, 2011

March 18, 2011 (Nijmegen, the Netherlands) — A new protocol in which a series of automated blood-pressure measurements is taken over 30 minutes while a patient sits alone in a quiet room is as good as daytime ambulatory BP monitoring (ABPM) at detecting white-coat and masked hypertension, say researchers in the Netherlands [1].

This is the first time that these two methods, which use the same BP monitoring device, have been compared in a primary-care setting, say Dr Mark C van der Wel (Radboud University Nijmegen Medical Centre, Nijmegen, the Netherlands) and colleagues in their paper in the March-April 2011 issue of the Annals of Family Medicine.

Patients say, 'Oh this is nice, I can sit here for 30 minutes and then it's done.'

van der Wel told heartwire that the new approach--called serial automated office BP measurement (OBPM)--"does require some organizational changes; for example, in my practice we had to arrange to have a room free in the afternoon, twice a week, so we could do these types of measurement. You have to be creative." But from the perspective of the patient, van der Wel says they have had good feedback. "What are the alternatives to detect white-coat hypertension? Twenty-four–hour monitoring or home monitoring, both of which ask a lot of a patient and are inconvenient. Patients say, 'Oh this is nice, I can sit here for 30 minutes and then it's done.' "

Up to 25% of People Suffer From White-Coat Hypertension

van der Wel and colleagues explain that up to a quarter of people are prone to white-coat hypertension, whereby they exhibit elevated BP in a clinical setting, but not in other settings. "As a consequence, the determined cardiovascular risk will be incorrect in an estimated 25% of patients and may lead to under- or overtreatment," they observe.

They add that a growing number of practices in the developed world already possess one or more automated oscillometric BP measuring devices, so the staff is already familiar with them, and this has enabled increased use of ABPM and home blood-pressure monitoring, with guidelines starting to recommend these two methods as ways of detecting white-coat hypertension. But these two approaches are not without problems: patient compliance can affect home BP monitoring, for example, and 24-hour ABPM is laborious, "costly, and not suitable for all types of patients."

The new office-based method has been shown to practically eliminate white-coat hypertension by one research group, say the Dutch researchers. For this study, van der Wel and colleagues developed a new protocol that enabled this method to be used in a primary-care setting, testing it in 84 patients.

They used the same BP monitoring device (Welch Allyn Cardioperfect 6100) for both the serial automated OBPM--during which BP was measured automatically every five minutes for 30 minutes with the patient alone in a room--and the daytime ABPM. The mean BPs by both methods were very similar, with a difference of less than 2 mm Hg between the two. And both approaches classified normotension, white-coat hypertension, masked hypertension, and sustained hypertension equally, the researchers note.

Office-Based Method Can't Detect Diurnal BP Patterns or BP Variability

van der Wel said his team has just completed another study confirming the reproducibility of these results, which has been accepted for publication, and the next step will be to demonstrate that the new method is cost saving, which he believes it will be.

But this method will not be able to provide some measures obtained from 24-hour ambulatory BP monitoring--such as diurnal BP patterns, BP variability, and mean nighttime BP--he points out.

van der Wel collaborates in a research project aiming at improvement in hypertension management with an unconditional grant by Novartis to cover the material costs of the study. Disclosures for the coauthors are listed in the paper.