title: Assessment of low-flow, low-gradient, severe aortic stenosis: an invasive evaluation is required for decision making.
abstract: Low-flow, low-gradient severe aortic stenosis (AS) is characterised by a small aortic valve area (AVA) and low mean gradient (MG) secondary to a low cardiac output and may occur in patients with either a preserved or reduced left ventricular ejection fraction (LVEF). Symptomatic patients presenting with low-flow, low-gradient severe AS have a dismal prognosis independent of baseline LVEF if managed conservatively and should therefore undergo aortic valve replacement if feasible. Transthoracic echocardiography (TTE) is the first-line investigation for the assessment of AS haemodynamic severity. However, when confronted with guideline-discordant AVA (small) and MG (low) values, there are several reasons other than severe AS combined with a low cardiac output which may lead to such a situation, including erroneous measurements, small body size, inherent inconsistencies in the guidelines' criteria, prolonged ejection time and aortic pseudostenosis. The distinction between these various entities poses a diagnostic challenge. However, it is important to make a distinction because each has very different implications in terms of risk stratification and therapeutic management. In such instances, cardiac catheterisation forms an integral part of the work-up of these patients in order to confirm or refute the echocardiographic findings to guide management decisions appropriately.
authors.affiliation: Department of Cardiology, Bern University Hospital, University of Bern, Bern, Switzerland.
authors.forename: Crochan J
authors.initials: CJ
authors.lastname: O'Sullivan
authors.forename: Fabien
authors.initials: F
authors.lastname: Praz
authors.forename: Stefan
authors.initials: S
authors.lastname: Stortecky
authors.forename: Stephan
authors.initials: S
authors.lastname: Windecker
authors.forename: Peter
authors.initials: P
authors.lastname: Wenaweser
mesh_terms: D001024:Aortic Valve Stenosis / Q000175:diagnosis*; D049628:Body Size; D006328:Cardiac Catheterization; D004452:Echocardiography; D006439:Hemodynamics; D006801:Humans