¹ South Western Sydney Area Hypertension Service, Bankstown Hospital, Sydney, NSW, Australia.

Abstract

White coat hypertension/effect (WCH/E) compromises the detection and management of hypertension (HT). Any simple methodology that can overcome this in the office environment, without requiring ambulatory blood pressure monitoring (ABPM), would be of great benefit. The BpTRU (VSM Med-Tech Ltd., Vancouver, BC, Canada) is an independently validated device that automatically measures blood pressure (BP) every 2 minutes over a 10 minute period, averaging the last 5 measurements.

We sought to compare BP measurement with the BpTRU to physician, nurse, and ABPM. We also determined the prognostic value of each by their discrimination for left ventricular hypertrophy (LVH). The incidence of WCE/H was compared with ABPM.

109 patients referred for assesment of hypertension had BP measurement with mercury sphygmomanometry by physician and nurse, BpTRU, and ABPM (awake average). LVH was assessed by echocardiography. BP results expressed as mmHgsem.

BpTRU readings by BpTRU and the nurse were significantly lower than those by the physician, but higher than by ABPM. These differences were greater for systolic than diastolic BP, see Table. There was a significant difference in systolic BP between groups with and without LVH for ABPM (1402 mmHg cw 1322 mmHg, p<0.005), BpTRU (1503 mmHg cw 1444 mmHg, P=0.042) and nurse (1513 cw 142, but not physician. Diastolic BP did not discriminate for LVH. The incidence of WCH/E cw ABPM fell from 29% by physician, to 15% with nurse (p<0.0001) and 16% with BpTRU (p<0.0001).

Automatic averaged office BP measurement with the BpTRU significantly reduces office WCH/E, being comparable to nurse measurement, and approaching that of ABPM. BP measurement by BpTRU and ABPM, unlike usual physician office measurement, is prognostic of hypertensive target organ injury. This methodology offers a valid alternative to ABPM in many patients.