Author + information
- Received November 28, 2016
- Revision received December 26, 2016
- Accepted January 5, 2017
- Published online February 6, 2017.
- aInstitut Universitaire de Cardiologie et de Pneumologie de Québec (Québec Heart and Lung Institute), Laval University, Québec, Québec, Canada
- bUniversity of Ottawa Heart Institute, University of Ottawa, Ottawa, Ontario, Canada
- ↵∗Address for correspondence:
Dr. Philippe Pibarot, Institut Universitaire de Cardiologie et de Pneumologie de Québec (Quebec Heart and Lung Institute), 2725 Chemin Sainte-Foy, #A-2075, Québec, Québec, Canada, G1V 4G5.
Up to 40% of patients with aortic stenosis (AS) harbor discordant Doppler-echocardiographic findings, the most common of which is the presence of a small aortic valve area (≤1.0 cm2) suggesting severe AS, but a low gradient (<40 mm Hg) suggesting nonsevere AS. The purpose of this paper is to present the role of multimodality imaging in the diagnostic and therapeutic management of this challenging entity referred to as low-gradient AS. Doppler-echocardiography is critical to determine the subtype of low-gradient AS: that is, classical low-flow, paradoxical low-flow, or normal-flow. Patients with low-flow, low-gradient AS generally have a worse prognosis compared with patients with high-gradient or with normal-flow, low-gradient AS. Patients with low-gradient AS and evidence of severe AS benefit from aortic valve replacement (AVR). However, confirmation of the presence of severe AS is particularly challenging in these patients and requires a multimodality imaging approach including low-dose dobutamine stress echocardiography and aortic valve calcium scoring by multidetector computed tomography. Transcatheter AVR using a transfemoral approach may be superior to surgical AVR in patients with low-flow, low-gradient AS. Further studies are needed to confirm the best valve replacement procedure and prosthetic valve for each category of low-gradient AS and to identify patients with low-gradient AS in whom AVR is likely to be futile.
Dr. Pibarot is the Canada Research Chair in Valvular Heart Diseases, Canadian Institutes of Health Research (CIHR), Ottawa, Ontario, Canada. His research program is funded by research grant # FDN-143225 from CIHR.
Dr. Pibarot has received a research grant from Edwards Lifesciences and Medtronic for echocardiography core laboratory analyses in transcatheter heart valves. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose.
- Received November 28, 2016.
- Revision received December 26, 2016.
- Accepted January 5, 2017.
- American College of Cardiology Foundation
- Central Illustration
- Classification of AS and Different Types of Low-Gradient AS
- Technical Reasons Leading to Low-Gradient AS
- Physiological Reasons Leading to Low-Gradient AS
- Inconsistencies in Guidelines Criteria for Severe AS
- Management of Low-Gradient AS