Natural history of paradoxical low-gradient severe aortic stenosis.
BACKGROUND
Up to 30% of patients with severe aortic stenosis (SAS; indexed aortic valve area <0.6 cm(2)/m(2)) present with low transvalvular gradient despite a normal left ventricular ejection fraction. Presently, there is intense controversy as to the prognostic implications of such findings. Accordingly, the aim of the present work was to compare the natural history of patients with paradoxical low-gradient (PLG) or high-gradient (HG) SAS.


RESULTS
We prospectively studied 349 patients with SAS and preserved left ventricular ejection fraction. Patients were categorized into HG-SAS (n=144) and PLG-SAS (n=205) according to mean transvalvular gradient (mean gradient >40 or ≤40 mm Hg). Primary end points were all-cause mortality and echocardiographic disease progression. To evaluate natural history, patients undergoing aortic valve replacement were censored at the time of surgery (n=92). During a median follow-up of 28 months, 148 patients died. Kaplan-Meier survival curves showed better survival in PLG-SAS than in HG-SAS, both in the overall population (48% versus 31%; P<0.01) and in the asymptomatic subgroup (59% versus 35%; P<0.02). In asymptomatic patients, Cox analysis identified age, diabetes mellitus, left atrial volume, and mean gradient as independent predictors of death. Finally, at last echocardiographic follow-up, PLG-SAS demonstrated significant increases in mean gradient (from 29±6 to 38±11 mm Hg; P<0.001).


CONCLUSIONS
Our study indicates that PLG-SAS is a less malignant form of AS compared with HG-SAS, because their spontaneous outcome is better. We further demonstrated that patients with PLG-SAS are en route toward the more severe HG-SAS form, because the majority of them evolve into HG-SAS over time.
From Pôle de Recherche Cardiovasculaire, Institut de Recherche Expérimentale et Clinique, Université Catholique de Louvain, Brussels, Belgium, and Division of Cardiology, Cliniques Universitaires Saint-Luc, Brussels, Belgium.
Frédéric
F
Maes
From Pôle de Recherche Cardiovasculaire, Institut de Recherche Expérimentale et Clinique, Université Catholique de Louvain, Brussels, Belgium, and Division of Cardiology, Cliniques Universitaires Saint-Luc, Brussels, Belgium.
Jamila
J
Boulif
From Pôle de Recherche Cardiovasculaire, Institut de Recherche Expérimentale et Clinique, Université Catholique de Louvain, Brussels, Belgium, and Division of Cardiology, Cliniques Universitaires Saint-Luc, Brussels, Belgium.
Sophie
S
Piérard
From Pôle de Recherche Cardiovasculaire, Institut de Recherche Expérimentale et Clinique, Université Catholique de Louvain, Brussels, Belgium, and Division of Cardiology, Cliniques Universitaires Saint-Luc, Brussels, Belgium.
Christophe
C
de Meester
From Pôle de Recherche Cardiovasculaire, Institut de Recherche Expérimentale et Clinique, Université Catholique de Louvain, Brussels, Belgium, and Division of Cardiology, Cliniques Universitaires Saint-Luc, Brussels, Belgium.
Julie
J
Melchior
From Pôle de Recherche Cardiovasculaire, Institut de Recherche Expérimentale et Clinique, Université Catholique de Louvain, Brussels, Belgium, and Division of Cardiology, Cliniques Universitaires Saint-Luc, Brussels, Belgium.
Bernhard
B
Gerber
From Pôle de Recherche Cardiovasculaire, Institut de Recherche Expérimentale et Clinique, Université Catholique de Louvain, Brussels, Belgium, and Division of Cardiology, Cliniques Universitaires Saint-Luc, Brussels, Belgium.
David
D
Vancraeynest
From Pôle de Recherche Cardiovasculaire, Institut de Recherche Expérimentale et Clinique, Université Catholique de Louvain, Brussels, Belgium, and Division of Cardiology, Cliniques Universitaires Saint-Luc, Brussels, Belgium.
Anne-Catherine
AC
Pouleur
From Pôle de Recherche Cardiovasculaire, Institut de Recherche Expérimentale et Clinique, Université Catholique de Louvain, Brussels, Belgium, and Division of Cardiology, Cliniques Universitaires Saint-Luc, Brussels, Belgium.
Siham
S
Lazam
From Pôle de Recherche Cardiovasculaire, Institut de Recherche Expérimentale et Clinique, Université Catholique de Louvain, Brussels, Belgium, and Division of Cardiology, Cliniques Universitaires Saint-Luc, Brussels, Belgium.
Agnès
A
Pasquet
From Pôle de Recherche Cardiovasculaire, Institut de Recherche Expérimentale et Clinique, Université Catholique de Louvain, Brussels, Belgium, and Division of Cardiology, Cliniques Universitaires Saint-Luc, Brussels, Belgium. jean-louis.vanoverschelde@uclouvain.be.
Jean-Louis
JL
Vanoverschelde
D000368:Aged; D001021:Aortic Valve / Q000000981:diagnostic imaging; D001024:Aortic Valve Stenosis / Q000000981:diagnostic imaging* / Q000503:physiopathology; D018450:Disease Progression; D015150:Echocardiography, Doppler / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D011379:Prognosis; D011446:Prospective Studies; D012720:Severity of Illness Index; D013318:Stroke Volume / Q000502:physiology*; D016277:Ventricular Function, Left / Q000502:physiology*
aortic stenosis; aortic valve replacement; gradient