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2952 Patients (P) underwent 3,135 Ambulatory
BP Monitors (ABPM). Only the initial ABPM
was used in this analysis. Of the 2,952 ABPM,
442 P had no drug information and were
excluded. The remaining 2510 ABPM were
analysed. All ABPM data is prospectively
entered into CARDIOFILE, which is a
comprehensive Cardiology database. Common
definitions for BP abnormalities can
therefore be standardized for accuracy and
reproducibility.
DEFINITIONS.
(A)White Coat Hypertension(WCH),
was defined as (1) Day time average systolic
BP (SBP) of <140mmHg by ABPM, and, (2) No
antihypertensive drugs, and (3) An Abnormal
office SBP using WHO/ISH criteria of
>150mmHg.
(B)White Coat Syndrome
Normotensive(WCSN), This definition varies
from WCH in that the P is normotensive while
taking antihypertensive drugs.
(C)White Coat Syndrome
Hypertensive(WCSH), was defined as (1) Day
time average SBP of >140mmHg by ABPM with
or without antihypertensive drugs, and an
office SBP of >150mmHg, and, >15mmHg
higher than the average daytime SBP.
RESULTS.
(1). 506 P had a normal ABPM and were not
taking any antihypertensive drugs. Of these
506, 118 P had WCH representing 23.3% of
normotensive and 4.7% of the entire
population.
(2). 754 P had a normal ABPM and all were
taking antihypertensive drugs. Of these 754,
217 P had WCSN as defined, representing
28.8% of controlled hypertensives.
(3). 1250 P had an abnormal ABPM, 739
(59.l%) were taking antihypertensive drugs.
Of these 1250, 660 P had WCSH, representing
52.8% of the uncontrolled hypertensive
population.
CONCLUSIONS.
WCH is uncommon representing only 4.7% of
2510 P presenting for ABPM. The true
incidence of WCH is likely even lower in the
general population, since the P in the study
were usually referred for a specific BP
problem.
In the poorly controlled hypertensive
population a white coat component to the
ABPM profile is common (52.8%). We have
classified these P as WCSH, indicating that
this group have SBP which are above current
recommendations at home with even higher SBP
measurements in the office setting.
In Those P whose SBP is well controlled the
incidence of a white coat component to their
SBP profile approaches that of the
normotensive population (viz; 23.3% vs
28.8%).
Finally we believe that Patients thought to
have White Coat Hypertension are far more
likely just to be truely hypertensive.
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