(261) Access to Home Blood Pressure Monitor on Outcomes of Chronic Hypertension in Pregnancy: CHAP Secondary

Treatment of mild chronic hypertension (CHTN) to a blood pressure (BP) goal of less than 140/90mmHg improves pregnancy outcomes (CHAP Trial). Home BP monitoring is a practical method of monitoring BP. Thus, we aimed to assess whether having a home blood pressure monitor at home or not modified pregnancy outcomes in the original CHAP trial. 


Study Design:

Secondary analysis of the CHAP trial, an RCT of antihypertensive treatment versus no treatment of pregnant patients with mild chronic hypertension. Ownership of a home BP monitor was by patient report at time of enrollment. The primary outcome was the CHAP composite of pregnancy outcomes. Secondary outcomes included individual components of the composite, severe HTN and others analyzed (Table). We analyzed whether the effect of treatment the outcomes differed by whether the patient had a home BP monitor using linear or logistic regression model as appropriate, with p< 0.05 as significant for interaction.


Results:

Of 2,325 patients who reported on home BP monitor, 1,298 (55.8%) had a monitor and 1,027 did not. Of the patients with a home BP monitor, 50.2%, were in the active treatment arm as were 50.4% of those without home BP monitor. For baseline characteristics, there were no significant interactions between treatment assignment and having a home BP monitor, except healthcare insurance (p = 0.0093). Overall, having a home BP monitor did not change the effect of treatment of CHTN on the primary outcome (p=0.625) or any secondary outcome (Table). 


Conclusion:

The effect of treatment of mild CHTN on the CHAP primary composite outcome and other outcomes including severe hypertension and mean BP did not appear to differ by whether pregnant patients had a home BP monitor. Further studies should investigate whether using a home BP influences treatment outcomes.