(934) Efficacy of acute antihypertensive therapy on resolution of severe hypertension relative to prior oral regimen

To evaluate whether class of oral antihypertensive medication impacts response to acute antihypertensive agents in treatment of severe hypertensive episodes in pregnancy and postpartum.

Study Design:

Retrospective analysis at a single academic tertiary care center (2015-2017) of patients who received acute treatment for severe hypertension during pregnancy or postpartum period with intravenous labetalol, intravenous hydralazine, or immediate release oral nifedipine. Data pertaining to oral antihypertensive medication regimen, acute IV antihypertensive therapy, duration of treatment and time to resolution of the severe hypertensive episode were abstracted from electronic health records and the response to treatment was compared among three groups: those who received the same class of medication as their prior home regimen, a different class, and those who were not on medication prior to the acute episode. A Cox proportional hazards model incorporated factors associated with time to resolution of severe hypertension.

Results:

Of 776 patients with severe hypertension, 465 met inclusion criteria. 96 (21%) were on an oral antihypertensive regimen prior to the acute event. Pretreatment mean arterial pressure (MAP), body mass index > 45 kg/m², self-reported non-Hispanic black race, and treatment with the same class of medication were associated with longer duration of severe hypertension in the adjusted proportional hazards model evaluating factors associated with duration of severe hypertension up to 2 hours after treatment. Duration of severe hypertension varied significantly between the three oral antihypertensive regimen groups (P < .01).

Conclusion:

For those patients on an oral antihypertensive agent prior to their presentation with an acute hypertensive episode, delayed resolution of severe hypertension is associated with acute treatment using the same class of medication as the patient’s prior oral antihypertensive regimen.