OFFICE BLOOD PRESSURE MEASUREMENT: MEAN OF TWO OR OF THREE VALUES?

Abstract

Objective: ESC/ESH 2018 hypertension guidelines recommend the calculation of the average of the last 2 blood pressure(BP) measurements(out of 3).This recommendation does not strictly correspond to previous recommendations of the ESC/ESH guidelines and to those of other international Societies.Furthermore, in several clinical trials mean BP values were calculated in different ways, more frequently by using the mean of three values(out of 3 measurements),or the mean of the last two (out of 2 or out of 3). Aim of the study was to evaluate the effect of different methods for the calculation of the mean BP values on observed BP values and their relationship with hypertension mediated organ damage. Design and method: In 206 patients BP was measured by a physician with an automated validated oscillometric device(3 measurements at 1 min intervals after 5 minutes of rest).Mean values were computed by using a)the first two measurements (SAP1/2 and DAP1/2)or b)the last two(SAP2/3 and DAP2/3)or c)three measurements (SAP1/2/3 and DAP1/2/3).All patients also underwent an echocardiogram. Results: Mean age was 58 ± 15 years,57%F,BMI 27 ± 5,85% were hypertensives(78%treated).BP values were as follows:SAP1/2:135.5 ± 17.4; SAP1/2/3:134.0 ± 17.1;SAP2/3:132.4 ± 16.9 mmHg(ANOVA p < 0.01 for all comparisons);DAP1/2:77.4 ± 11.0;DAP1/2/3:77.0 ± 11.0;DAP2/3:76.7 ± 11.3(ANOVA p < 0.01 only for DAP1/2 vs DAP2/3).Left ventricular mass index(LVMI/h2.7) was correlated with all three means of SAP:(SAP1/2: r = 0.164, p < 0.05;SAP1/2/3:r = 0.168;SAP2/3:r = 0.185).Despite a trend for a better correlation between LVMI/h2.7 and SAP2/3,no difference between the correlation coefficients was observed at the Steiger’s Zeta test.Also the correlations between mean BP values and left atrial volume were similar (SAP1/2: r = 0.174;SAP1/2/3:r = 0.169;SAP2/3:r = 0.170,p < 0.05). Conclusions: BP values are lower when the mean of the last two values out of three is calculated as recommended by the 2018 ESC/ESH guidelines. Despite this, no difference in the correlations of mean BP values with cardiac organ damage were observed.