Author + information
- Received January 7, 2015
- Revision received March 23, 2015
- Accepted April 2, 2015
- Published online October 1, 2015.
- Navtej S. Chahal, MBBS∗,†,
- Maria Drakopoulou, MD∗,
- Ana M. Gonzalez-Gonzalez, MD∗,
- Ramasamy Manivarmane, MBBS∗,
- Rajdeep Khattar, MBBS∗,† and
- Roxy Senior, MD∗,†,‡∗ ()
- ∗Royal Brompton Hospital, London, United Kingdom
- †Biomedical Research Unit, National Heart and Lung Institute, Imperial College London, United Kingdom
- ‡Northwick Park Hospital, Harrow, United Kingdom
- ↵∗Reprint requests and correspondence:
Prof. Roxy Senior, Royal Brompton Hospital and National Heart and Lung Institute, Imperial College, London, United Kingdom.
Objectives This study sought to assess the diagnostic impact of stress echocardiography (SE) in patients with suspected low-flow, low-gradient aortic stenosis but normal resting transvalvular flow rate.
Background SE may help to distinguish between true severe aortic stenosis and pseudosevere aortic stenosis in patients with low aortic valve area (AVA) and mean gradient. However, if rest flow rate is normal, then SE may not confer any additional diagnostic value, irrespective of resting left ventricular ejection fraction (LVEF) and indexed stroke volume (SVi).
Methods Sixty-seven patients with suspected low-flow, low-gradient aortic stenosis who underwent SE were retrospectively studied. Following stratification by rest LVEF, SVi, and flow rate—using cutoffs of 50%, 35 ml/m2, and 200 ml/s, respectively—we tested for significant changes in AVA during SE.
Results Mean age was 77 ± 9 years and 60% of patients were male. Mean values for rest variables were as follows: AVA: 0.77 ± 0.12 cm2; mean gradient: 27 ± 7 mm Hg; flow rate: 182 ± 37 ml/s; SVi: 32 ± 8 ml/m2; and LVEF: 45 ± 15%. During SE, significant increases in AVA were observed regardless of resting LVEF and SVi state. In patients with rest flow rate ≥200 ml/s, AVA did not increase significantly during stress (rest AVA: 0.90 cm2 vs. stress AVA: 0.97 cm2; p = 0.11), and positive predictive value for confirming underlying true severe aortic stenosis was 84%. In adjusted analyses, rest flow rate was the only parameter associated with severe AS (odds ratio: 1.05, 95% confidence interval: 1.0 to 1.1; p = 0.002).
Conclusions Rest AVA measured under normal flow rate conditions is likely to reflect the true severity of AS and unlikely to change significantly with SE. Flow normalization may only be required in patients with AVA <1 cm2 and mean gradient <40 mm Hg when the rest flow rate is <200 ml/s.
Prof. Senior has served on the Speakers Bureau of Bracco. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose.
- Received January 7, 2015.
- Revision received March 23, 2015.
- Accepted April 2, 2015.
- American College of Cardiology Foundation