Table 1

Summary of class I and II AHA/ACC recommendations for choice of prosthetic valve

Recommendations for valve replacement with a mechanical prosthesisClass
1. Patients with expected long life spansI
2. Patients with a mechanical prosthetic valve already in place in a different position than the valve to be replacedI
3. Patients in renal failure, on haemodialysis, or with hypercalcaemiaII
4. Patients requiring warfarin treatment because of risk factors* for thromboembolismIIa
5. Patients ≤65 years for AVR and ≤70 years for MVRIIa
Recommendations for valve replacement with a bioprosthesis
Class I There is evidence and/or general agreement that a given procedure or treatment is useful and effective.
Class II There is conflicting evidence and/or a disagreement of opinion about the usefulness/efficacy of a procedure or treatment.
Class IIa Weight of evidence/opinion is in favour of usefulness/efficacy.
Class IIb Usefulness/efficacy is less well established by evidence/opinion.
*Risk factors: atrial fibrillation, severe left ventricular dysfunction, previous thromboembolism, and hypercoagulable condition.
AVR, aortic valve replacement; MVR, mitral valve replacement.
1. Patients who cannot or will not take warfarin treatmentI
2. Patients ≥65 years needing AVR who do not have risk factors for thromboembolism*I
3. Patients considered to have possible compliance problems with warfarin treatmentIIa
4. Patients >70 years needing MVR who do not have risk factors for thromboembolism*IIa
5. Valve rereplacement for thrombosed mechanical valveIIb