Cardiovascular Disease in Pregnancy Part IV: Pulmonary Hypertension, Marfan's, and Bicuspid Aortic Valve

Pulmonary Hypertension 

• What is PH? 

  • Elevation in mean pulmonary arterial pressure (PAP) >/= 25 mmHg upon right heart catheterization 

  • PAH or pulmonary arterial hypertension = subset of PH characterized by LV filling pressure </= 15 mmHg and a pulmonary vascular resistance > 3 Wood Units 

  • Why is it important in pregnancy? 

    • Mortality remains high in women with PH (9-28% mortality) 

    • There is a recommendation to avoid pregnancy, and termination should be discussed 

    • Greatest risk = during labor and immediately postpartum 

    • Causes of death most commonly are pulmonary hypertensive crisis, pulmonary thrombosis, and right heart failure 

  • What to do if they get pregnant

    • Echocardiography to evaluate heart function 

    • Right heart catheterization is recommended if diagnostic uncertainty 

    • Multidisciplinary team to care for mother in a tertiary care center 

    • Consider anticoagulation as thrombo-embolism is a major risk 

    • Diuretics if heart failure 

  • Delivery 

    • Multidisciplinary delivery team 

    • Vaginal delivery can be associated with volume changes during contractions → can pose a problem to women with pulmonary hypertension because they have a limited capability to increase their cardiac output 

    • Remember: cardiac output increases 30% in first stage of labor and >50% in second stage of labor 

    • Planned cesarean may be a better choice - but we need to monitor hemodynamic arterial and central venous pressure

    • Postpartum - also need to observe closely due to fluid shifts. Continue to record strict I/Os and optimize RV function

• Marfan’s Syndrome 

  • Overall risk is aortic dissection associated with pregnancy → ~3% 

  • Aortic size is a major determinant of risk, but even women with aortic root of <40 mm, risk of dissection is 1% 

  • Pregnancy should be avoided in Marfans if aortic root is >45 mm → increased risk of dissection 

  • If 40-45mm, other factors like rate of growth and family history should be considered 

• Bicuspid Aortic Valve 

  • Can also lead to aortic dilatation; occurs in less than 50% of patients with a bicuspid aortic valve 

  • The dilatation can be in the distal ascending aorta which cannot be seen well with echo 

  • Risk of dissection is overall small, but pregnancy should be avoided if aorta diameter is >50 mm 

• General considerations in the antepartum 

  • Testing for mom 

    • EKG 

    • Echo - with unexplained or new cardiovascular signs or symptoms, or known cardiac disease in pregnancy 

    • Exercise testing 

    • Other tests 

  • Genetic testing and counseling 

    • Prepregnancy counseling of course, and risk assessment with the mWHO classification of maternal risk 

    • High risk patients should be treated by a multidisciplinary pregnancy heart team  

    • Genetic counseling should be considered if congenital heart disease or congenital arrhythmias, cardiomyopathies, aortic disease, or genetic malformation associated with CVD 

      • Why? Increased risk of fetal congenital heart disease in moms with these issues (baseline 1% goes up to 3-5%) 

  • Labor and delivery

    • Vaginal delivery is generally recommended as first choice for most patients unless the have the following, at which point cesarean should be considered: 

      • Dilatation of the ascending aorta >45 mm, severe aortic stenosis, preterm labor while on oral anticoagulants, PH, Eisenmenger’s syndrome, or severe heart failure 

    • IOL should be considered by 40 weeks at the latest 

    • Postpartum: discussion of birth control and prevention of next pregnancy 

    • Postpartum testing of maternal cardiac status 

  • Fetal assessment 

    • Fetal echo when there is an elevated risk of fetal abnormalities 

    • Consideration of growth ultrasounds as there is higher risk of FGR 

    • Consideration of fetal testing