(370) Hypertension-Related Postpartum Morbidity Following Discharge: A Comparison of Nifedipine and Labetalol Monotherapy

To evaluate rates of hypertension-related morbidity after delivery discharge among individuals on nifedipine vs labetalol monotherapy.

Study Design:
This was a retrospective cohort study of individuals who delivered at a quaternary care center from 1/1/21-1/20/24 and were discharged on nifedipine or labetalol monotherapy. The primary outcome was hypertension-related morbidity within 30 days of delivery discharge, defined as a new diagnosis of: preeclampsia lab abnormalities, HELLP syndrome, eclampsia, pulmonary edema/acute heart failure, cerebrovascular disorders, myocardial infarction/cardiac arrest, liver hematoma, acute renal failure and ICU admission. Secondary outcomes included 30-day hospital re-presentation and new-onset severe preeclampsia. Baseline characteristics were abstracted from the medical record by an Informatics team. Chart review was performed for post-discharge outcomes. Bivariate analysis was used to compare groups. Multivariable logistic regression was used to adjust for baseline characteristics and hypertension readmission risk factors.

Results:

Of 361 patients meeting criteria, 33.2% were discharged on nifedipine and 66.8% on labetalol. Nifedipine recipients had lower BMI and were less likely to have preexisting renal disease or chronic hypertension compared to labetalol recipients (Table 1). Those on nifedipine had higher maximum systolic and diastolic blood pressure (BP) from delivery to discharge, but lower maximum systolic BP in the 24h prior to discharge. Individuals on nifedipine had lower rates of hospital re-presentation (12.5 vs 4.6%, p = 0.006), new-onset severe preeclampsia (2.5 vs 0%, p = 0.01) and hypertension-related morbidity (3.3 vs 0.4%, p = 0.03) (Table 2). After controlling for covariates (renal disease, race, BMI and maximum BP in the 24h prior to discharge), nifedipine was independently associated with reduced odds of post-discharge morbidity (aOR 0.09, 95% CI 0.01—0.8; p = 0.03).

Conclusion:
Among individuals on antihypertensive monotherapy at delivery discharge, nifedipine was associated with reduced odds of post-discharge morbidity compared to labetalol.