Adjusting Cardiac Medications in Pregnancy and Lactation Varies By Disease State, Panelists Say

This panel, part of an American College of Cardiology (ACC) initiative, features moderator Jessie Dunne, PharmD, BCPS, BCCP, FACC, a clinical pharmacist at Oregon Health & Science University, as well as panelists:

• Kayle Shapero, MD, PhD, a cardiologist at Brown University Health and assistant professor of medicine at Brown University's Warren Alpert Medical School;
• and Ashley Schenk, PharmD, AACC, BCCP, BCPS, a cardiology clinical pharmacist at University of Kentucky (UK) HealthCare and an adjunct assistant professor at the UK College of Pharmacy.

Shapero explains that the only pillar of guideline-directed medical therapy (GDMT) that can stay through pregnancy is the β-blocker. Angiotensin-converting enzyme (ACE) inhibitors, angiotensin receptor blockers, angiotensin receptor-neprilysin inhibitors, and mineralocorticoid receptor antagonists are teratogenic or unsafe, and there is little data on sodium-glucose cotransporter 2 inhibitors. Clinicians often substitute hydralazine with long-acting nitrates. Schenk says diuretics need careful balance: blood volume rises by about 50% during pregnancy, the placenta still needs adequate perfusion, and overdiuresis can reduce breast milk supply. During lactation, enalapril and spironolactone can be restarted, but the panelists say some patients may go without optimal therapy for long periods. For that reason, they recommend discussing lactation goals before delivery and revisiting them over time.

On hypertension, Schenk recommends moving patients with chronic hypertension to agents such as labetalol or nifedipine before conception when possible. Shapero notes that the American College of Obstetricians and Gynecologists now recommends treatment above 140/90 mmHg in pregnancy, a change based on newer evidence that tighter control is beneficial. She also points out that preeclampsia often presents in the postpartum period, and that systolic pressures of 160 mmHg or higher call for intravenous therapy. After roughly 6 weeks postpartum, targets return to American Heart Association and American College of Cardiology recommendations. Shapero adds that ACE inhibitors such as enalapril and captopril are underused options during lactation. Schenk recalls that under older guidelines, her own large peripartum rise in blood pressure went untreated.

The panelists call anticoagulation the most “anxiety-provoking” area. They stress that a mechanical valve does not rule out pregnancy, and that warfarin at doses below 5 mg may reasonably be continued. Schenk explains that enoxaparin needs antifactor Xa monitoring because volume of distribution changes during pregnancy, and that delivery requires coordinated planning across specialties. For postpartum patients, Dunne weighs relative infant dose calculations for direct oral anticoagulants in patients who lactate, as well as the demands of warfarin management for new mothers.

On arrhythmias, Shapero says many patients can stay on β-blockers or flecainide, and that adenosine and cardioversion are appropriate in acute settings. They suggest that health care professionals should avoid amiodarone and most class III agents when time allows. Schenk adds that fetal supraventricular tachycardia can be treated by giving the mother flecainide or digoxin.