segunda-feira, abril 12, 2010
Estenose aórtica com gradiente baixo
Predictors of Outcomes in Low-Flow, Low-Gradient Aortic Stenosis
One hundred one patients with low-flow, low-gradient aortic stenosis (aortic valve area ≤1.2 cm2, left ventricular ejection fraction ≤40%, and mean gradient ≤40 mm Hg) underwent dobutamine stress echocardiography and an assessment of functional capacity using the Duke Activity Status Index. A subset of 72 patients also underwent a 6-minute walk test. Overall survival was 70±5% at 1 year and 57±6% at 3 years. After adjusting for age, gender, and the type of treatment (aortic valve replacement versus no aortic valve replacement), significant predictors of mortality during follow-up were a Duke Activity Status Index ≤20 (P=0.0005) or 6-minute walk test distance ≤320 m (P<0.0001, in the subset of 72 patients), projected aortic valve area at a normal transvalvular flow rate ≤1.2 cm2 (P=0.03), and peak dobutamine stress echocardiography left ventricular ejection fraction ≤35% (P=0.03). More severe stenosis, defined as projected aortic valve area ≤1.2 cm2, was a predictor of mortality only in the no aortic valve replacement group. The Duke Activity Status Index, 6-minute walk test, and left ventricular ejection fraction improved significantly during follow-up in the aortic valve replacement group, but remained unchanged or decreased in the no aortic valve replacement group.
Conclusion— In patients with low-flow, low-gradient aortic stenosis, the most significant risk factors for poor outcome were (1) impaired functional capacity as measured by Duke Activity Status Index or 6-minute walk test distance; (2) more severe valve stenosis as measured by projected aortic valve area at a normal transvalvular flow rate; and (3) reduced peak stress left ventricular ejection fraction, a composite measure accounting for both resting left ventricular function and contractile reserve.
Continua interessante esse debate.
Quando o gradiente é baixo, ao repouso, o prognóstico é pior.
Este outro, de livre acesso, é mais interessante ainda.