Cardiac Disease in Pregnancy

  • Risk of pregnancy depends on specific disease and patients condition, individual counselling by experts is recommended
  • Risk stratification is important, and even the lowest-risk patients still have up to 5% risk of peripartum

Pregnancy is a:

This describes the general management of the pregnant patient with cardiac disease. Management of peripartum cardiomyopathy is covered under Peripartum Cardiomyopathy.

Epidemiology and Risk Stratification

Risk stratification can use:

  • Risk prediction model
    Provides good general-purpose stratification for patients who may have very individual disease, and a spread of functional stratifications within their lesion.
    • ZAHARA
    • CARPREG II
  • WHO Classification
    Comprehensive but may be less useful as does not stratify lesions by severity of that individuals pathology.

CARPREG II

Predictors:

  • General
    • Prior cardiac events
      Includes:
      • Failure
      • Stroke or TIA
      • Arrhythmias
    • NYHA III/IV or resting SpO2 <90%
    • High-risk valve LVOT/ obstruction
    • Mild or greater systemic ventricular dysfunction
    • No previous cardiac intervention
  • Lesion-specific
    • Mechanical valves
    • High-risk aortopathies
    • Pulmonary hypertension
    • Coronary artery disease
  • Care related
    • Late pregnancy assessment

WHO Risk Stratification

Low (WHO I) risk:

  • Cardiology followup limited to one or two visits
  • Includes:
    • Uncomplicated or mild:
      • PS
      • PDA
      • MV prolapse
    • Repaired lesions
    • Isolated ectopics

Moderate (WHO II) risk:

  • Require cardiology followup every trimester
  • Includes:
    • Uncorrected ASD or VSD
    • Repaired ToF
    • Most arrhythmias

Moderate-severe (WHO II-III) risk:

  • Classification depends on individual presentation
  • Includes:
    • Mild LV dysfunction
    • HCM
    • Valvular heart disease that is not WHO I or WHO IV
    • Repaired coarctation

Severe (WHO III) risk:

  • High risk of complications requiring at least monthly cardiology and obstetric review
  • Mechanical valve
  • Systemic RV or Fontan
  • Cyanotic heart disease
  • Other complex congenital heart disease
  • Aortic dilatation:
    • 40-45mm in Marfan’s
    • 45-50mm with bicuspid AV

Contraindications to Pregnancy

These patients are also classified as Critical (WHO IV) risk.

Pregnant women who will not consider termination require at least monthly review.

  • Severe Pulmonary Hypertension
    Mortality up to 50%.
  • Severe LV dysfunction
    NYHA III-IV or LVEF <30%.
  • Previous peripartum cardiomyopathy
  • Severe obstructive cardiac disease
    • HOCM
    • Symptomatic Aortic stenosis
    • Mitral stenosis
    • Pulmonary stenosis
    • Unrepaired coarctation
  • Aortic dilatation:
    • ⩾45mm in Marfan’s
    • ⩾50mm with bicuspid AV
  • Severe coarctation

Pathophysiology

Key conditions:

  • Mitral stenosis is the most common lesion in the pregnant patient
    Poorer prognosis with decompensated disease, i.e.:
    • AF
      May precipitate cardiac failure.
    • Pulmonary hypertension
    • May be treated with percutaneous commissurotomy
  • Marfan’s syndrome
    • Aortic dissection
      Very high risk due to hyperdynamic circulation.
    • Requires monthly echocardiography
      • Aortic root dilatation >50mm strongly consider delivery
    • Vaginal delivery possible if aorta <40mm
      Risk of straining leading to dissection.
  • Pulmonary Hypertension
    • Highest risk is in the week following delivery

Consequences:

  • Neonate
    Complications occur in 20-38% of women with cardiac disease, with key risk factors:
    • NYHA >II
    • Maternal LVOT obstruction
    • Smoking
    • Multiple gestation
    • Use of oral anticoagulants
    • Mechanical valve

Clinical Manifestations

Assessment aims are to determine level of function:

  • Exercise tolerance
  • HR, BP, and SpO2
  • Medical therapy
    With particular attention to:
    • Amiodarone
    • Warfarin
    • ACE-I/A2RBs

Investigations

Key investigations include:

  • Bloods
    • Haemoglobin
    • Coagulation status
  • ECG
  • Echocardiogram
    For any pregnant patient with new or changing symptoms
  • Cardiac MRI

Management

Highly complicated patients with extensive preparation required:

  • Multidisciplinary approach
    • Anaesthesia
    • Obstetrics
    • Maternal-foetal medicine
      • Obstetric cardiology
    • Intensive care
    • Neonatology
  • Tertiary centre
    • Adult ICU available
  • Optimise underlying cardiac disease

Specific Therapy:

  • Procedural
    • Delivery
      Generally planned for between 28-34 weeks.
      • Vaginal delivery
        • Preferred in:
          • Severe hypertension
            Aim for a “stress free” labour.
          • Early epidural is recommended
            Beware the fixed cardiac-output state.
        • Avoid in:
          • Aortic dissection
          • Marfan’s syndrome with severe aortic root dilatation
      • Caesarian delivery:
        • Aortic dilation >45mm
        • Severe AS
        • Pre-term labour on anticoagulants
        • Eisenmenger’s syndrome
        • Severe heart failure

Anaesthetic Considerations

  • C
    • Nature of lesion
      • Shunts
        Required SpO2 and ETCO2.
      • Air embolisation
    • Vascular access
    • Circulation goals
      • Enhance pulmonary flow
      • Optimise CO
      • Optimise oxygenation
  • D
    • Anaesthetic technique
      • Regional
        • Advantages
          • Partner in room
          • Avoids risks of GA
          • Allows slow titration of anaesthetic
            CSE or epidural.
          • Better post-operative analgesia
          • Reduced blood loss
          • Reduced PONV
        • Disadvantages
          • Partner in room
          • Anticoagulation
          • Maternal anxiety
            Subsequent CVS effects.
          • Complications of regional
          • Cannot give 100% oxygen
      • General
        • Advantages
          • Controlled situation
          • Reliable
          • Anticoagulation status not relevant
          • Reduced maternal anxiety
          • Easier invasive vascular access
          • Facilitate cardiopulmonary bypass or ECMO
        • Disadvantages
          • Airway and ventilation risks
          • Haemodynamic perturbation
            Especially at intubation and extubation.
          • Effect of anaesthetic agents
            • Negative inotropy
            • Cardiac conduction abnormalities
            • Reduced SVR
            • Tocolysis
          • Risk of awareness
          • Greater blood loss
          • Poorer post-operative analgesia, PONV
  • I
    • Endocarditis prophylaxis
      Required in the setting of:
      • Unrepaired cyanotic CHD
      • Repaired CHD with prosthesis
        In first 6 months.
      • Repaired CHD with residual defects

The technique chosen will usually come down to the risk-benefit evaluation of the patient, and the skill and preference of the team.

Complications

Consequences of cardiac disease in pregnancy include:

  • Maternal
    • Death
    • C
      • Arrhythmias
      • Heart failure
        Uterine contraction results in mobilisation of uterine blood volume that may precipitate fluid overload.
    • D
      • CVA
    • H
      • Embolism
  • Foetal
    • Death
    • SGA
    • Prematurity

Prognosis

References

  1. Endorsed by the European Society of Gynecology (ESG), the Association for European Paediatric Cardiology (AEPC), and the German Society for Gender Medicine (DGesGM), Authors/Task Force Members, Regitz-Zagrosek V, et al. ESC Guidelines on the management of cardiovascular diseases during pregnancy: The Task Force on the Management of Cardiovascular Diseases during Pregnancy of the European Society of Cardiology (ESC). European Heart Journal. 2011;32(24):3147-3197. doi:10.1093/eurheartj/ehr218