Projected Valve Area at Normal Flow Rate Improves the Assessment of Stenosis Severity in Patients With Low-Flow, Low-Gradient Aortic Stenosis: The Multicenter TOPAS (Truly or Pseudo-Severe Aortic Stenosis) Study (original) (raw)
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The international journal of cardiovascular imaging, 2018
Low-dose dobutamine stress echocardiography (DSE) is a valuable tool to distinguish true-severe (TS) from pseudo-severe (PS) low gradient aortic valve stenosis (LGAS) in patients with reduced left ventricular ejection fraction (LVEF). However, only scanty studies reported the clinical utility of DSE in differentiating TS-LGAS patients with preserved LVEF. We investigated the clinical utility of DSE in LGAS patients with preserved LVEF and the echocardiographic determinants suggestive of TS-LGAS. 130 consecutive LGAS patients [indexed aortic valve area (AVA) ≤ 0.6cm/m and mean trans-aortic pressure gradient (PG) < 40mmHg] with preserved (≥ 50%, n = 63) and reduced (< 50%, n = 67) LVEF were included. DSE defined TS-LGAS (projected AVA ≤ 1 cm) in 61.2% patients with reduced LVEF and in 68.3% patients with preserved LVEF. Multivariate logistic regression analysis showed that baseline AVA was an independent determinant of TS-LGAS both in LVEF ≥ 50% (OR 0.45, P = 0.004) and LVEF <...
JACC: Cardiovascular Imaging, 2015
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/m 2 , and 200 ml/s, respectively-we tested for significant changes in AVA during SE. RESULTS Mean age was 77 AE 9 years and 60% of patients were male. Mean values for rest variables were as follows:
JACC: Cardiovascular Imaging, 2013
The objective of this study was to examine the value of stress-echocardiography in patients with paradoxical low-flow, low-gradient (PLFLG) aortic stenosis (AS). The projected aortic valve area (AVA Proj ) at a normal flow rate was calculated in 55 patients with PLFLG AS. In the subset of patients (n ϭ 13) who underwent an aortic valve replacement within 3 months after stress echocardiography, AVA Proj correlated better with the valve weight compared to traditional resting and stress echocardiographic parameters of AS severity (AVA Proj : r ϭ Ϫ0.78 vs. other parameters: r ϭ 0.46 to 0.56). In the whole group (N ϭ 55), 18 (33%) patients had an AVA Proj Ͼ1.0 cm 2 , being consistent with the presence of pseudo severe AS. The AVA Proj was also superior to traditional parameters of stenosis severity for predicting outcomes (hazard ratio: 1.32/0.1 cm 2 decrease in AVA Proj ). In patients with PLFLG AS, the measurement of AVA proj derived from stress echocardiography is helpful to determine the actual severity of the stenosis and predict risk of adverse events. (J Am Coll Cardiol Img 2013;6:175-83) We previously reported that a significant proportion of patients with severe aortic stenosis (AS) on the basis of aortic valve area (i.e., AVA Ͻ1.0 cm 2 and indexed AVA Ͻ0.6 cm 2 /m 2 ) may have a restrictive physiology resulting in lower left ventricular (LV) outflow (i.e., stroke volume index Ͻ35 ml/m 2 ) and lower than expected transvalvular gradients (i.e., Ͻ40 mm Hg)
Assessment of Aortic Valve Stenosis Severity
Circulation, 2000
Background-Fluid energy loss across stenotic aortic valves is influenced by factors other than the valve effective orifice area (EOA). We propose a new index that will provide a more accurate estimate of this energy loss. Methods and Results-An experimental model was designed to measure EOA and energy loss in 2 fixed stenoses and 7 bioprosthetic valves for different flow rates and 2 different aortic sizes (25 and 38 mm). The results showed that the relationship between EOA and energy loss is influenced by both flow rate and aortic cross-sectional area (A A) and that the energy loss is systematically higher (15Ϯ2%) in the large aorta. The coefficient (EOAϫA A)/(A A ϪEOA) accurately predicted the energy loss in all situations (r 2 ϭ0.98). This coefficient is more closely related to the increase in left ventricular workload than EOA. To account for varying flow rates, the coefficient was indexed for body surface area in a retrospective study of 138 patients with moderate or severe aortic stenosis. The energy loss index measured by Doppler echocardiography was superior to the EOA in predicting the end points, which were defined as death or aortic valve replacement. An energy loss index Յ0.52 cm 2 /m 2 was the best predictor of adverse outcomes (positive predictive value of 67%). Conclusions-This new energy loss index has the potential to reflect the severity of aortic stenosis better than EOA. Further prospective studies are necessary to establish the relevance of this index in terms of clinical outcomes.
Journal of Clinical Ultrasound, 2020
Purpose: We aimed to study the safety and feasibility of low-dose dobutamine stress echocardiography in a symptomatic high gradient aortic stenosis population scheduled for transfemoral transcatheter aortic valve implantation (TAVI) and to quantify left ventricular (LV) flow reserve. Methods: Fifty patients underwent dobutamine stress echocardiography with 5 minutes increments of 5 μg/kg/min up to 20 μg/kg/min until the heart rate increased ≥20 beats/min from baseline or exceeded 100 beats/min. Other criteria for discontinuing the infusion were major adverse events: ventricular arrhythmia, persistent supraventricular arrhythmia, pulmonary edema, chest pain with significant STchanges, or minor events: ST-changes, drop in systolic blood pressure >30 mmHg, mild chest pain, and/or dyspnea. LV flow reserve was defined as an increase in stroke volume ≥20% during the test. Results: Of 50 patients, 45 completed the test according to protocol. No patient had major adverse event. Five patients experienced minor side effects: mild chest pain/ dyspnea in three, self-terminating atrial flutter in one, and decrease in blood pressure in one. Significant LV flow reserve was observed in 20 patients (40%). Conclusion: Low-dose dobutamine stress test appeared safe and feasible patients with high gradient aortic stenosis, and showed LV flow reserve in a minority of them.
Low Flow Low Gradient Severe Aortic Stenosis: Diagnosis and Treatment
Aortic Stenosis - Current Perspectives [Working Title]
Approximately 40% of patients with aortic stenosis (AS) show discordant Doppler-echocardiographic parameters with aortic valve area (AVA) <1 cm 2 and/or index iAVA <0.6 cm 2 /m 2 (consistent with severe AS) and the mean gradient (MG) <40 mmHg, consistent with mild/moderate AS. Accurate diagnosis of true severe low flow low gradient AS versus pseudo-severe aortic stenosis is important for prognosis and optimal timing for intervention. Doppler echocardiography using intravenous low dose dobutamine challenge is widely used for differentiating pseudo-severe from true severe aortic stenosis. However, relying on echocardiography alone may have limitations in accurate diagnosis. Reliable diagnosis using echocardiography is dependent on multiple factors like the angle of interrogation of the aortic jet, the assumption that the LVOT area is circular in cross section, optimal echo windows, the presence of underlying subclinical coronary artery disease prior to dobutamine challenge etc. In this chapter, we describe non-invasive and invasive strategies to assess the aortic valve using dobutamine stress. Direct measurement of gradients across the aortic valve while estimating the change in cardiac output and aortic valve area with increments of dobutamine infusion dose is complementary, safe and useful when conventional echocardiography techniques are inconclusive. Finally, the chapter describes effective strategies of treatment for low gradient severe aortic stenosis, including the role for diagnostic balloon valvuloplasty, in the era of transcatheter valve replacement (TAVR).