Author + information
- Anastasia Vamvakidoua,b,
- Navtej Chahala,b,
- Reinette Hampsona,b,
- Nikolaos Karogiannisa,b,
- Wei Lia,b,
- Rajdeep Khattara,b and
- Roxy Seniora,b
Background: During low-dose dobutamine stress echocardiography in low-flow low-gradient aortic stenosis (LFLGAS), both the aortic stenosis severity and the presence of contractile reserve are conventionally assessed based on stroke volume flow reserve (SVFR) (stroke volume increase ≥20%). However frequent exaggerated chronotropic response to dobutamine results in stroke volume drop, as opposed to transvalvular flow rate (FR) (stroke volume/ejection time) and left ventricular ejection fraction (LVEF) which may increase. We aimed to assess the value of FR ≥200ml/s (normal FR) and LVEF change in the identification of true severe aortic stenosis (TSAS) and the assessment of contractile reserve respectively.
Methods: Accordingly 74 consecutive patients (mean age 78 years) with LFLGAS referred for low-dose dobutamine stress echocardiography for the determination of aortic stenosis severity and contractile reserve underwent retrospective assessment of stroke volume, FR, LVEF and standard echocardiographic parameters of aortic stenosis severity. All-cause mortality censored for aortic valve intervention was assessed.
Results: SVFR was present in 30 (40.5%) of the 74 patients whereas FR≥200ml/s was achieved in 60 (81.1%) (p<0.001). During the median follow-up of 316.5 days 28 (37.8%) deaths occurred.
Amongst all standard echocardiographic predictors of stenosis severity at peak stress and clinical prognostic factors, aortic valve area was an independent predictor of death (p=0.03), and was therefore used to define TSAS (stress aortic valve area ≤1.01cm2). TSAS was present in 47 (63.5%) patients of whom SVFR correctly identified 17 (36.2%) compared to 34 (72.3%) with FR≥200ml/s (p=0.001).
Amongst stroke volume, FR and LVEF changes, only the latter was an independent predictor of death (p=0.02). LVEF change of <5% was the best cut-off for the prediction of death (p=0.004) and therefore for determination of contractile reserve.
Conclusions: During low-dose dobutamine stress echocardiography in LFLGAS normalised FR, not SVFR, is a better determinant of TSAS, whereas assessment of LVEF change instead of SVFR determines contractile reserve.
Moderated Poster Contributions
Non Invasive Imaging Moderated Poster Theater, Poster Hall, Hall C
Saturday, March 18, 2017, 4:00 p.m.-4:10 p.m.
Session Title: Technical Advances in Transthoracic Echocardiography
Abstract Category: 28. Non Invasive Imaging: Echo
Presentation Number: 1264M-05
- 2017 American College of Cardiology Foundation