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Information ⬇

Author: John B. Chambers

Significant valve disease occurs in 13% of people aged over 75. The main aetiologies in industrialized countries are calcific aortic stenosis and functional mitral regurgitation. The population prevalence of mitral prolapse is 2% and of bicuspid aortic valve about 1%.

Heart valve disease may present:

Priorities ⬆ ⬇

  • Immediate echocardiography (Table 51.1) is indicated for unexplained hypotension or pulmonary oedema. A murmur may be inaudible in the presence of low flow even with severe valve disease.
  • If there is a coincidental murmur in a patient presenting with a clear non-valve problem, echocardiography is indicated with an urgency depending on the clinical circumstance. Echocardiography should be performed before non-cardiac surgery unless this is an emergency.
  • Refer for immediate advice from a cardiologist if there is:
    • Severe valve disease or
    • Apparently moderate valve disease with prior exertional symptoms or current hypotension, pulmonary oedema or LV impairment on the echocardiogram
  • Consider the causes of acute valve disease or deterioration in previously stable valve disease (Table 51.2).

Further Management ⬆ ⬇

Outline

This depends on the valve lesion.

Severe Aortic Stenosis Presenting with Heart Failure!!navigator!!

  • Start a loop diuretic.
  • If hypotensive start dobutamine (p. 13 Table 2.7).
  • The only definitive treatment is valve replacement (or a transcatheter procedure).
  • A low left ventricular ejection fraction may be reversible and is not a contraindication to aortic valve replacement.

Severe Aortic Stenosis Noted Incidentally!!navigator!!

  • Symptomatic severe aortic stenosis is a contraindication to all but life-saving non-cardiac surgery.
  • Asymptomatic severe aortic stenosis requires a cardiology opinion but usually the original management plan can proceed if the non-cardiac surgery is low or moderate risk. The following precautions are necessary:
    • Invasive monitoring and HDU nursing.
    • Avoid epidural anaesthetics (which may cause vasodilatation).
    • Avoid vasodilators, for example angiotensin-converting enzyme inhibitors, which should only be used under specialist guidance.
    • Avoid drugs with negative inotropic effect.
    • Moderate aortic stenosis may also cause symptoms and be associated with sudden death and should prompt cardiac referral.

Severe Aortic Regurgitation Presenting with Heart Failure!!navigator!!

  • Consider infective endocarditis.
  • Request an urgent cardiac opinion. This must be immediate if there are echocardiographic signs of a high LV end-diastolic pressure since these patients can deteriorate rapidly.
  • Critical aortic regurgitation can lead to vasoconstriction with normalization of the diastolic pressure (usually <70 mmHg and often 30 or 40 mmHg in severe regurgitation).
  • Give a loop diuretic.
  • If systolic BP <100 mmHg start dobutamine.
  • If oxygen saturation <92% despite 60% oxygen and patient tiring, discuss mechanical ventilation.
  • Discuss urgent specialist investigation and surgery with a cardiologist.

Severe Aortic Regurgitation Noted Incidentally!!navigator!!

  • Refer for a cardiology opinion especially if there are indications for surgery:
    • Exertional breathlessness
    • LV systolic diameter >50 mm or diastolic diameter >70 mm
    • Significant aortic root dilatation
  • Patients with compensated LV function usually tolerate non-cardiac surgery well.

Mitral Stenosis Presenting with Pulmonary Oedema!!navigator!!

  • Give a loop diuretic.
  • Left atrial pressure is highly dependent on heart rate. Treat atrial fibrillation with digoxin and if the ventricular rate is >100/min, add verapamil or a beta blocker. If there is sinus tachycardia give a beta blocker, for example metoprolol 25 mg 12-hourly PO.
  • Avoid mechanical ventilation unless essential because of the risks of circulatory collapse. Maintain peripheral vascular resistance with noradrenaline.
  • Discuss mitral valve replacement or balloon valvotomy with a cardiologist.

Mitral Stenosis Noted Incidentally!!navigator!!

  • Indications for surgery are:
    • Symptoms
    • High pulmonary artery pressure
    • RV dysfunction
  • Patients with severe mitral stenosis tolerate non-cardiac surgery and pregnancy badly even if asymptomatic. Refer for a cardiac opinion for considering urgent balloon valvotomy.

Mitral Regurgitation Presenting with Heart Failure!!navigator!!

  • Start a loop diuretic.
  • Start dobutamine if systolic BP <100 mmHg, or noradrenaline if systolic BP <90 mmHg.
  • Discuss with a cardiologist the insertion of a balloon pump preparatory to surgery.

Mitral Regurgitation Noted Incidentally!!navigator!!

  • Refer for a cardiology opinion especially if there are indications for surgery:
    • Exertional breathlessness
    • LV systolic diameter >40 mm (in repairable mitral prolapse)
  • Patients with LV compensation usually tolerate non-cardiac surgery well.

Prosthetic Heart Valve Presenting with Heart Failure!!navigator!!

Because of the difficulty of assessing prosthetic failure a cardiac referral should be made even if there is severe LV dysfunction sufficient to cause the presentation.

  • Obstruction is recognized by reduced or absent opening of the cusps or mechanical leaflet associated with a high-pressure drop across the valve on echocardiography.
  • Regurgitation is obvious if there is a large regurgitant colour jet but may be suspected if there is rocking of the prosthesis or the combination of highly active left ventricle and low cardiac output.

Prosthetic Valve As a Coincidental Observation!!navigator!!

The main concern is management of anticoagulation. Avoid giving vitamin K antagonists unless emergency correction is essential.

INR high and no active bleeding (see Chapter 103)INR high and no active bleeding (see Chapter 103)
  • If INR >5 omit 1-2 doses checking the INR daily and restart at a lower dose.
  • If INR >8 give vitamin K 1-5 mg orally.
Active bleeding (see Chapter 103)Active bleeding (see Chapter 103)

If there is active bleeding which cannot be controlled by direct pressure (e.g. intracerebral or gastrointestinal):

  • Give vitamin K IV (not intramuscularly) in 1 mg aliquots.
  • Consider IV prothrombin complex, or if not available then fresh frozen plasma.
If INR low or a surgical procedure is planned (see Chapter 103)If INR low or a surgical procedure is planned (see Chapter 103)

IV heparin gives better control of anticoagulation than s/c:

  • If INR is below 2.0 start IV heparin.
  • If elective surgery is planned, stop warfarin and start IV heparin when the INR falls below 2.0.

Other Complications Associated with Prosthetic Heart Valves!!navigator!!

Thromboembolism

  • The risk of thromboembolism is most closely related to non-prosthetic factors, for example atrial fibrillation, large left atrium, impaired left ventricle.
  • Check that there are no signs of prosthetic dysfunction (breathlessness, abnormal murmur, muffled closure sound) or signs of infective endocarditis (Chapter 52).
  • Look at the anticoagulation record and check INR, full blood count, C-reactive protein and blood culture (three sets) if white cell count or C-reactive protein raised.
  • If INR <2 for a mechanical valve and there is no evidence of endocarditis discuss an increase in warfarin dose with a haematologist. Target INR according to ESC guidelines, (Table 51.3). Arrange an early appointment with the anticoagulation clinic.
  • Investigate also for other potential causes. Arrange carotid USS.
  • If thromboembolism persists discuss with a cardiologist and consider transoesophageal echocardiography looking for thrombus or pannus formation (endothelial overgrowth which can be a nidus for thrombus formation).

Fever

  • Always consider infective endocarditis but do not forget non-cardiac causes.
  • Send three sets of blood cultures before starting antibiotic therapy. Staphylococcus aureus, and coagulase negative staphylococci are the most common organisms in the first year after surgery and after this, as for native endocarditis, Staphylococcus aureus (including MRSA), Viridans group streptococci (e.g. S. mutans), Streptococcus bovis group, and Enterococci.
  • The sensitivity of transthoracic echo for vegetations is much lower than for native valves, and TOE is often necessary to confirm the diagnosis, especially in mechanical valves.
  • Surgery is more likely to be necessary in prosthetic than native valve endocarditis

Anaemia

  • Investigate as for any anaemia, not forgetting the possibility of infective endocarditis.
  • Virtually all mechanical valves produce minor haemolysis (disrupted cells on the film, high LDH and bilirubin, low haptoglobin) caused by normal transprosthetic regurgitation. Usually the haemoglobin remains normal.
  • Haemolytic anaemia suggests leakage usually around the valve (paraprosthetic regurgitation), which is often small and only detectable on transoesophageal echocardiography.
  • Refer for advice from a cardiologist and haematologist.

Further Reading ⬆

Nishimura RA, Otto CM, Bonow RO, et al. (2014) AHA/ACC Guideline for the management of patients with valvular heart disease. J Am Coll Cardiol 63, e57–e185. DOI: 10.1016/j.jacc.2014.02.536.

The Joint Task Force on the Management of Valvular Heart Disease of the European Society of Cardiology (ESC) and the European Association for Cardio-Thoracic Surgery (EACTS) (2012) Guidelines on the management of valvular heart disease (version 2012). European Heart Journal 33, 2451–2496. DOI: 10.1093/eurheartj/ehs109.