The aim of this study is to test the diagnostic added value of Volume Challenge (VC) to low-dose dobutamine stress echocardiography (LDDSE) in patients with a low-flow, low-gradient aortic stenosis (LFLGAS). This study will assess if LDDSE plus VC allows to increase the proportion of patients in whom a true severe AS can be differentiated from a pseudo severe AS.
The design of the study is a monocentric prospective non-randomized pilot clinical trial. A standard LDDSE will be performed. The stroke volume (SV) will be recorded. The addition of VC with the passive leg raise method at peak dobutamine dose will be performed. A transesophageal echocardiography (TEE) with low dose dobutamine and a bolus of normal saline will be performed as a validation method to measure AVA with the planimetry method. The SV will be recorded. Proportion of patient receiving the diagnosis of true severe AS defined as a combination of AVA \<1.0 cm2 and ∆SV ≥ 20% will be compared between standard LDDSE and LDDSE with addition of VC. Calculating sensitivity, specificity, performing ROC curve analysis and calculating the Youden-index, the accuracy of the test method (LDDSE plus passive leg raising) for the detection of truly severe AS in comparison with the reference method (TEE) will be determined.
Study Type
INTERVENTIONAL
Allocation
NA
Purpose
DIAGNOSTIC
Masking
NONE
Enrollment
50
Addition volume challenge with passive leg raising method in LDDSE as well as administration of normal saline and dobutamine during TEE
Bern University hospital
Bern, Switzerland
Diagnosis of true severe AS
Proportion of patients receiving the diagnosis of true severe AS defined as a combination of AVA \<1.0 cm2 and ∆SV ≥ 20% will be compared between standard LDDSE and LDDSE with addition of VC
Time frame: Measures taken during echocardiograph a few minutes after administration of VC
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