(657) Automated unattended office BP: is your clinician raising your blood pressure?

There is emerging data that in non-pregnant adults measuring clinic blood pressure (CBP) without a clinician present (unattended CBP) may reduce the “white coat effect” and be closer to mean out-of-clinic blood pressure (BP) compared to traditional CBP measurements that involve a clinician in the room (attended CBP).  Our objective was to compare unattended CBP with attended CBP in pregnant women with hypertension (HTN).


Study Design:

Pregnant patients with a history of chronic or gestational HTN defined using ACOG diagnostic criteria were included in this analysis. Demographic variables were described as median [IQR] for continuous variables and frequencies for categorical variables. Automated attended and unattended CBP were measured at up to two prenatal visits and compared using a paired t-test to account for repeated measures and between-subject variability. Bland-Altman plots were created to evaluate the agreement between unattended and attended CBP.


Results:

Of 26 pregnant patients with HTN, women were on average 36.5 [5.1] years old and 24 weeks pregnant, with a BMI of 32.2 [8.3] kg/m², 19% had diabetes, and the majority were working full time (Table). In 49 paired measurements, the mean unattended CBP was 115.8/72.3 mmHg and the mean attended CBP was 116.5/71.5 mmHg. The mean difference (95% CI) between unattended and attended systolic BP was 0.69 (-1.40, 2.78) and diastolic BP was 0.00 (-1.02, 1.02); both mean differences were not statistically significant P >0.5 (Figure).


Conclusion:

In pregnant patients with HTN, having a provider present during CBP measurements did not result in a statistically significant BP elevation. Based on these findings unattended CBP measurement may not be able to replace out-of-office BP measurement for the diagnosis of white coat hypertension; further research is needed.