The cuff-based measurement of blood pressure (BP) in atrial fibrillation (AF) is considered as difficult and uncertain and the accuracy of automated BP monitors in AF is regarded questionable.
A systematic PubMed search was conducted for identifying studies comparing automated (oscillometric or automated auscultatory) BP measurements versus manual auscultatory (mercury or aneroid sphygmomanometers) or intra-arterial BP measurements in patients with sustained AF.
Fifteen articles including 13 non-invasive studies (N = 877; 5 home, 2 ambulatory, 4 office BP monitors) and 4 invasive studies (N = 179; 2 office, 2 home monitors) were included in meta-analyses. There was a significant heterogeneity in the validation procedure used for comparing BP measurements in different studies. Meta-analysis of non-invasive studies showed pooled correlation coefficients between auscultatory and automated BP measurements to be stronger for systolic (SBP) than diastolic BP (DBP) (r 0.87 versus 0.76, p < 0.05). Automated BP measurements were slightly higher than auscultatory measurements (pooled average SBP difference 0.5 mmHg, 95% confidence intervals [CI] −0.9, 1.9; DBP 1.5 mmHg, 95% CI −0.6, 3.6). Meta-analysis of invasive studies showed automated SBP to be lower than intra-arterial SBP measurements (pooled difference −4.2 mmHg, 95% CI −8.4, −0.02), whereas automated DBP was higher (6.1 mmHg, 95% CI: 3.8, 8.4).
There is significant heterogeneity in the non-invasive validation studies of automated BP monitors in AF. The current evidence suggests acceptable agreement of automated with auscultatory BP measurements, which is further supported by limited invasive studies showing similar relationship as in sinus rhythm. There seems to be a consistent trend towards more accurate measurement of systolic BP and overestimation of diastolic BP, which however is less important in AF patients who are usually elderly with systolic hypertension.
Hypertension Center STRIDE-7, University of Athens, School of Medicine, Third Department of Medicine, Sotiria Hospital, Athens, Greece