PCI: As in non-pregnancy, heparin and clopidogrel are given prior to procedure. Bare metal stents are preferred to drug eluting stents because the risk of stent thrombosis is lower when clopidogrel has to be stopped for delivery. Aspirin should be continued. Fetal radiation dose from PCI is low. One study showed if maternal back and abdomen are protected and the area is coned down, increased risk to the fetus of dying of cancer within 15 years from 60 minutes is ~1:80000. Another states that coronary angiography exposes patients to 2.5-5.0 mSv and PCI exposes patients to 5.0-15.0 mSv, which are both below the threshold for teratogenicity at any gestational age. Care should be taken during the procedure due to fragility of vascular structures and risk of coronary dissection.

Thrombolysis: If PCI is not available, then treatment should continue as in the non-pregnant patient. There is little data on thrombolysis for MI in pregnancy. These medications are unlikely to cross to the placenta but have been associated with first-trimester pregnancy loss, preterm labor, maternal hemorrhage, abruption placenta, and fetal death. In comparison, complication rate for thrombolysis in pulmonary embolism is only 1%. Generally these patients should be considered for lytic therapy, if timely PCI is not available.

CABG: A small amount of information is available for CABG in pregnancy. However, one study states that maternal mortality from cardiopulmonary bypass surgery is up to 13% and the risk of fetal loss is near 30%.

Post-Cardiac Arrest Hypothermia: For the non pregnant post arrest patient, this therapy has become one accepted standard intervention. The data on use in pregnancy is limited but some hospital protocols may list pregnancy as a contraindication. Many clinicians follow the dictum that saving the mother takes precedence over potential risks to the fetus. Therefore, they will initiate therapeutic hypothermia in these patients. Consider proactively discussing this issue with your perinatology, OB, cardiology consultants to optimize hospital protocols to address this situation.

A pertinent letter was in 2011 New England Journal of Medicine:: In a review of therapeutic hypothermia in comatose survivors of cardiac arrest, Holzer includes pregnancy as a contraindication to hypothermia. Successful induced hypothermia after cardiac arrest in a pregnant woman at 13 weeks of gestation, with subsequent term delivery and normal development of her newborn, has been reported. Also, intraoperative hypothermia administered during cardiac surgery in pregnant women with successful delivery of the fetuses has been described. Varying degrees of hypothermia were used during these operations, with similar positive outcomes. There are theoretical risks to the fetus. In one study, fetal death occurred in up to 24% of mothers undergoing cardiopulmonary bypass with the concurrent use of hypothermia; however, whether this rate of death was attributed to hypothermia or the stress of cardiac surgery with hypothermia remains unknown.Induced hypothermia improves neurologic morbidity and mortality. Conversely, no evidence exists to support harm associated with hypothermia during pregnancy, and evidence does exist to suggest the safety of this practice. Thus, we believe that the potential benefit of induced hypothermia outweighs the theoretical but unproven risks to the fetus, mother, or both.