Cardiovascular Disease in Pregnancy
Cardiovascular disease remains a major cause of both morbidity and mortality during pregnancy and in the peripartum period, despite major advances in the care of such patients. The concept of the cardio-obstetric team has received renewed attention and importance in the 2018 European Society of Cardiology guidelines. We wish to present the following case which demonstrated the utility of multidisciplinary care in complex cardiac patients in terms of achieving excellent maternal and foetal outcomes.
A 38-year-old (G2P1) refugee from Eastern Europe was referred to our cardiology service regarding management of high-risk cardiovascular disease during her pregnancy. Her cardiovascular background was notable for prior history of rheumatic fever, culminating in a mechanical mitral valve replacement at 32 years old. Her background history was also notable for prior venous thromboembolism while taking the combined oral contraceptive pill. Her obstetric history was notable for prior lower segment Caesarean section in 2012 under general anaesthesia prior to her mitral valve replacement. Unfortunately, we were unable to get more specific details regarding prior surgery and transthoracic echocardiogram (TTE) results from her country of birth.
Given the complexity of the case, she was discussed as part of the local high-risk obstetric multidisciplinary team for optimal management of this patient. This included input from Obstetrics, Cardiology, Cardiothoracic Surgery, Haematology, Anaesthesia, and other allied healthcare staff.
She was categorised as maternal WHO Class III; current guidelines recommend at least monthly assessment as this risk stratification implies significant maternal and foetal risk during pregnancy, but not to a degree in which continuation of the pregnancy is contraindicated provided that relevant local expertise is available. The management of anticoagulation in patients with mechanical prostheses remains challenging; current ESC Guidelines recognise the paucity of high-quality evidence in this area. After meeting with the patient and discussing the potential options regarding management of her anticoagulation during pregnancy, consensus opinion was to switch to low molecular weight heparin with anti-factor Xa monitoring at least every two weeks and remain on same throughout her pregnancy until time of delivery.
TTE at 12 weeks demonstrated moderate-to-severe aortic regurgitation, preserved left ventricular function, with a wellseated mitral valve prosthesis and a moderate transvalvular gradient of 7mmHg. This was followed by serial studies conducted in the late second and third trimesters, which demonstrated a mild increase in the transvalvular gradient; this was discussed between cardiology and cardiothoracic surgery and was felt to be secondary to haemodynamic changes related to the pregnancy, given that mobile leaflets were seen without any concern for valve thrombosis morphologically and an otherwise unchanged appearance on imaging.
Elective Caesarean section was undertaken after 38 weeks gestation. Epidural anaesthesia with slow titration, with radial arterial line in situ for invasive blood pressure monitoring was undertaken. Low molecular weight heparin was stopped 24 hours prior to delivery, with anticoagulation restarted six hours post-delivery and bridging onto warfarin until a therapeutic INR was reached.
Thankfully, our patient underwent an uncomplicated Caesarean section and delivery of a healthy neonate without complication, and after overnight monitoring in our high dependency unit was felt to be stable enough to transfer back to the maternity hospital. On review in the outpatient cardiology clinic she remains clinically well and asymptomatic from a cardiovascular perspective, though she will require monitoring and follow-up of her native aortic valvular regurgitation and mechanical mitral prosthesis.