Predictors of outcomes in low-flow, low-gradient aortic stenosis : results of the multicenter TOPAS Study

Authors: Clavel, Marie-Annick; Fuchs, Christiana; Burwash, Ian; Mundigler, Gerald; Dumesnil, Jean G.; Baumgartner, Helmut; Bergler-Klein, Jutta; Beanlands, Robert S. B.; Mathieu, Patrick; Magne, Julien; Pibarot, Philippe
Abstract: Background—Patients with low-flow, low-gradient aortic stenosis have a poor prognosis with conservative therapy but a high operative mortality if treated surgically. Recently, we proposed a new index of aortic stenosis severity derived from dobutamine stress echocardiography, the projected aortic valve area at a normal transvalvular flow rate, as superior to other conventional indices to differentiate true-severe from pseudosevere aortic stenosis. The objective of this study was to identify the determinants of survival, functional status, and change in left ventricular ejection fraction during follow-up of patients with low-flow, low-gradient aortic stenosis. Methods and Results—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 (P0.0005) or 6-minute walk test distance 320 m (P0.0001, in the subset of 72 patients), projected aortic valve area at a normal transvalvular flow rate 1.2 cm2 (P0.03), and peak dobutamine stress echocardiography left ventricular ejection fraction 35% (P0.03). 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.
Document Type: Article de recherche
Issue Date: 30 September 2008
Open Access Date: Restricted access
Document version: VoR
This document was published in: Circulation, Vol. 118 (14 Suppl), S234-S242 (2008)
American Heart Association
Alternative version: 10.1161/CIRCULATIONAHA.107.757427
Collection:Articles publiés dans des revues avec comité de lecture

Files in this item:
477.62 kBAdobe PDF    Request a copy
All documents in CorpusUL are protected by Copyright Act of Canada.