Isolated clinic hypertension: diagnostic criteria based on 24-h blood pressure definition.
OBJECTIVE
The use of diagnostic criteria based on 24-h ambulatory blood pressure (BP) values could improve prognostic value by incorporating night BP, minimize biases and improve the diagnostic reproducibility of isolated clinic hypertension (ICH). We estimate the 24-h BP cut-off points that best discriminate and predict the two diagnostic thresholds of mean daytime BP for ICH (135/85 and 130/80 mmHg).


METHODS
Cross-sectional, comparative, multicentre study in 6176 untreated hypertensive patients, whose BP was measured by ambulatory BP monitoring. ICH was defined with an office BP of ≥140/≥90 mmHg and a daytime BP of <135/<85 mmHg (ICH1) or <130/80 mmHg (ICH2). Sensitivity, specificity, positive likelihood ratio (LR+), odds ratio (OR), error rate, predictive values, κ values and 95% confidence interval were calculated for each possible cut-off point for ICH1 and ICH2.


RESULTS
One thousand eight hundred and seven patients (29.2%) and 960 patients (15.5%) met ICH1 and ICH2 criteria, respectively. The 24-h BP cut-off points that best predict ICH1 and ICH2 are less than 132/82 mmHg (sensitivity: 93.6%, specificity: 94.3%, LR+: 16.6, OR: 1367.1, error rate: 5.9, κ 0.86) and less than 127/77 mmHg (sensitivity: 90.8%, specificity: 97.4%, LR+: 34.6, OR: 1041.5, error rate: 3.6,κ 0.86), respectively. These values achieved the best balance of sensitivity and specificity, together with the highest values of LR+ and OR and the lowest error rate.


CONCLUSIONS
The 24-h BP cut-off point that best predicts the daytime criterion of less than 135/85 and less than 130/80 mmHg are 132/82 and 127/77 mmHg, respectively. These 24-h cut-off points may add value to ambulatory blood pressure monitoring for both diagnostic and management future decisions.
Vinyoles
Ernest
E
La Mina Primary Care Center, University of Barcelona, CIBER Fisiopatologia de la Obesidad y Nutricion (CIBEROBN, Instituto de Salud Carlos III), Spain. 23561evb@comb.cat
Rodriguez-Blanco
Teresa
T
de la Sierra
Alejandro
A
Felip
Angela
A
Banegas
José R
JR
de la Cruz
Juan J
JJ
Gorostidi
Manuel
M
Sobrino
Javier
J
Segura
Julián
J
Roca-Cusachs
Alex
A
Ruilope
Luís M
LM
D000328:Adult; D018660:Blood Pressure Monitoring, Ambulatory; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D006973:Hypertension / Q000175:diagnosis* / Q000503:physiopathology; D016013:Likelihood Functions; D008297:Male; D008875:Middle Aged; D012680:Sensitivity and Specificity