[Calcified aortic stenosis with left ventricular dysfunction and low transvalvular gradients. Must one reject surgery in certain cases?].
The natural history of severe aortic stenosis (aortic valve area < 1 cm2 or < 0.6 cm2/m2) with left ventricular systolic dysfunction and low transvalvular gradients (mean gradient < 40 mmHg) is mediocre in the short term and the operative risk is high. Dobutamine echocardiography provides a reliable evaluation of the aortic obstacle by diagnosing the rare cases of relative aortic stenosis in which the valve surface area has been underestimated because of a low cardiac output (aortic surface area > 1.2 cm2 with a mean gradient < 30 mmHg with dobutamine): in this case, the limited available data suggests that medical therapy with strict follow-up of its efficacy is the best management. The other use of dobutamine echocardiography is to assess left ventricular contractile reserve, defined as a increase > or = 20% in stroke volume under dobutamine. Cases with a contractile reserve have an operative risk of 5 to 10% and the medium-term benefits of valve replacement have been demonstrated. In the absence of contractile reserve, the operative risk is much grater, 30 to 60%, and also depends on other parameters such as the mean basal transaortic pressure gradient (risk five times greater in cases with a mean gradient < 20 mmHg), the need for coronary bypass surgery and associated co-morbid conditions. The surgical contraindications are in fact relatively few and concern patients with several risk factors: absence of contractile reserve itself is not a definitive surgical contraindication.
Fédération de cardiologie, CHU Henri Mondor, AP-HP, 51, avenue de Lattre de Tassigny, 94 010 Créteil. jeanluc.monin@free.fr
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JL
Monin
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Guéret
D001024:Aortic Valve Stenosis / Q000150:complications* / Q000473:pathology* / Q000601:surgery; D002114:Calcinosis / Q000150:complications* / Q000473:pathology*; D002316:Cardiotonic Agents; D000075202:Contraindications; D001026:Coronary Artery Bypass; D004280:Dobutamine; D004452:Echocardiography / Q000379:methods; D006351:Heart Valves / Q000473:pathology; D006801:Humans; D018579:Patient Selection; D012307:Risk Factors; D018487:Ventricular Dysfunction, Left / Q000209:etiology*
D002316:Cardiotonic Agents; D004280:Dobutamine