Oral Combined Hydrochlorothiazide/Lisinopril Versus Oral Nifedipine for Postpartum Hypertension

Oral Combined Hydrochlorothiazide/Lisinopril Versus Oral Nifedipine for Postpartum Hypertension: A Comparative Effectiveness Pilot Randomized Controlled Trial

The purpose of this study is to see if a combined pill of Angiotensin-converting enzyme (ACE) inhibitors (a medication that helps relax your veins and arteries to lower your blood pressure) with diuretics (sometimes called water pills, help rid your body of salt and water) will control blood pressure better than a different blood pressure medication of calcium channel blocker (lower your blood pressure by preventing calcium from entering the cells of your heart and arteries). Both medications are part of our usual care for high blood pressure after delivery.

In individuals with preeclampsia, persistent hypertension and edema result in part from the mobilization of up to 8 liters of fluid and sodium from the extravascular to intravascular space. The increased urinary sodium excretion on days 3-5 postpartum likely results from higher atrial natriuretic peptide concentrations in plasma and activation of the renin-angiotensin-aldosterone system. Adding diuretics for postpartum hypertension has been associated with better blood pressure control in some of the studies.

• CVD is the leading cause for mortality worldwide.
• Primary prevention is more effective than treating CVD.
• Pregnancy is often the 1st adult engagement with the healthcare system.
• Preeclampsia is a risk factor for long term CVD, even after controlling for mutual risk factors.
• CVD is the leading cause for pregnancy related mortality.
• There is no good data regarding the optimal medications to control blood pressure after delivery.
• ACE inhibitors play an important role in controlling blood pressure outside of pregnancy and there is extensive evidence to support their cardioprotective effects.
• The optimal use of diuretics in the postpartum in patients with preeclampsia, require further study and clarification to augment current management schemes.

Hypothesis: that in postpartum women with hypertensive disorders, oral combined Hydrochlorothiazide/Lisinopril will reduce postpartum hypertension at 7 days after delivery compared to usual care with calcium channel blockers.

Inclusion Criteria:

• Postpartum women at ≥ 18 years of age
• Postpartum diagnosis of persistent hypertension (2 measurements of Systolic BP ≥150 and/or diastolic BP ≥ 100 or systolic BP ≥140 and/or diastolic BP ≥ 90 for people with diabetes) requiring an oral medication based on the ACOG criteria or
• Hypertensive disorder of pregnancy diagnosed antepartum or intrapartum requiring blood pressure medication in the postpartum
• Chronic hypertension requiring blood pressure medication postpartum

Exclusion Criteria:

• Urine output < 30 cc/h prior to screening for eligibility
• Creatinine > 1.4 during current admission
• End-stage renal disease
• Hypersensitivity to ACE inhibitors or sulfa drugs
• Idiopathic/hereditary angioedema
• Hyperkalemia (serum potassium >5 mEq/L) during current admission
• Pulmonary edema