Prognostic effect of long-axis left ventricular dysfunction and B-type natriuretic peptide levels in asymptomatic aortic stenosis.
Résumé
In aortic stenosis (AS), the increased afterload results in progressive structural and functional changes that precede the development of symptoms. We hypothesized that the detection of abnormalities in left ventricular long-axis function could identify patients with asymptomatic AS at increased risk of events. We prospectively examined the outcome of 126 patients with asymptomatic AS who underwent a comprehensive echocardiographic examination, including tissue Doppler imaging. B-type natriuretic peptide (BNP) was measured in all patients. During a median follow-up period of 20.3 + or - 17.8 months, 6 patients died, 8 developed symptoms but did not undergo surgery, and 48 underwent aortic valve replacement. On multivariate Cox regression analysis, the parameters associated with the predefined outcome were gender (p = 0.048), left atrial area index (p = 0.011), systolic annular velocity (p = 0.016), E/Ea ratio (p = 0.024), late diastolic annular velocity (p = 0.023), and BNP (p = 0.012). Using receiver operating characteristics curve analysis, a left atrial area index of > or = 12.4 cm(2)/m(2), systolic annular velocity of < or = 4.5 cm/s, E/Ea ratio >13.8, late diastolic annular velocity of < or = 9 cm/s, and BNP of > or = 61 pg/ml were identified as the best cutoff values to predict events. In conclusion, in asymptomatic AS, tissue Doppler imaging and BNP measurements provide prognostic information beyond that from clinical and conventional echocardiographic parameters.