Self-Management of Postnatal Hypertension: The SNAP-HT Trial.
Cairns AE., Tucker KL., Leeson P., Mackillop LH., Santos M., Velardo C., Salvi D., Mort S., Mollison J., Tarassenko L., McManus RJ., SNAP-HT Investigators None.
Hypertension affects 1 in 10 pregnancies, often persisting postpartum, when antihypertensive requirements may vary substantially. This unmasked, randomized controlled trial evaluated the feasibility and effects on blood pressure (BP) of self-management of postpartum hypertension. Women with gestational hypertension or preeclampsia, requiring postnatal antihypertensive treatment, were randomized to self-management or usual care. Self-management entailed daily home BP monitoring and automated medication reduction via telemonitoring. Women attended 5 follow-up visits during 6 months. The primary outcome was feasibility: specifically recruitment, retention, and compliance with follow-up rates. Secondary outcomes included BP control and safety, analyzed on an intention-to-treat basis. Forty-nine percent (91/186) of those women approached were randomized (45 intervention, 46 control), and 90% (82/91) finished follow-up. The groups had similar baseline characteristics. After randomization, BP was lower in the intervention group, most markedly at 6 weeks: intervention group mean (SD), systolic 121.6 (8.7)/diastolic 80.5 (6.6) mm Hg; control group, systolic 126.6 (11.0)/diastolic 86.0 (9.7) mm Hg; adjusted differences (95% confidence interval), systolic -5.2 (-9.3 to -1.2)/diastolic -5.8 (-9.1 to -2.5) mm Hg. Diastolic BP remained significantly lower in those self-managing to 6 months: adjusted difference -4.5 (-8.1 to -0.8) mm Hg. This is the first randomized evaluation of BP self-management postpartum and indicates it would be feasible to trial this intervention in larger studies. Self-management resulted in better diastolic BP control to 6 months, even beyond medication cessation. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT02333240.