Echocardiographic Assessment Of Aortic Stenosis Research Articles

Pitfalls and Tips in the Assessment of Aortic Stenosis by Transthoracic Echocardiography.

Aortic stenosis (AS) is a valvular heart disease that significantly contributes to cardiovascular morbidity and mortality worldwide. The condition is characterized by calcification and thickening of the aortic valve leaflets, resulting in a narrowed orifice and increased pressure gradient across the valve. AS typically progresses from a subclinical phase known as aortic sclerosis, where valve calcification occurs without a transvalvular gradient, to a more advanced stage marked by a triad of symptoms: heart failure, syncope, and angina. Echocardiography plays a crucial role in the diagnosis and evaluation of AS, serving as the primary non-invasive imaging modality. However, to minimize misdiagnoses, it is crucial to adhere to a standardized protocol for acquiring echocardiographic images. This is because, despite continuous advances in echocardiographic technology, diagnostic errors still occur during the evaluation of AS, particularly in classifying its severity and hemodynamic characteristics. This review focuses on providing guidance for the imager during the echocardiographic assessment of AS. Firstly, the review will report on how the echo machine should be set to improve image quality and reduce noise and artifacts. Thereafter, the review will report specific emphasis on accurate measurements of left ventricular outflow tract diameter, aortic valve morphology and movement, as well as aortic and left ventricular outflow tract velocities. By considering these key factors, clinicians can ensure consistency and accuracy in the evaluation of AS using echocardiography.

Abstract 10206: Misleading Transvalvular Hemodynamics for Patients With Moderate Aortic Stenosis

Introduction: Aortic stenosis (AS) is a progressive disease that leads to cardiac remodeling. Appropriate management depends on accurate assessment of AS severity. Transvalvular gradients are central to echocardiographic assessment of AS though can be impacted by any conditions that decrease transvalvular flow. Hypothesis: 1) Decline in peak transvalvular gradient over time is associated with more significant cardiac remodeling and 2) Cardiac damage is associated with lower transvalvular flow and masks progression of AS. Methods: Retrospective single center study of patients with moderate AS (defined as peak gradient 25-40mmHg) from 2013-2020 with > 1 transthoracic echocardiogram (TTE). Each TTE was classified into established stages of cardiac damage: no damage (Stage 0), left ventricular damage (Stage 1), left atrial or mitral valve damage (Stage 2), pulmonary vasculature or tricuspid valve damage (Stage 3), or right ventricular damage or subclinical heart failure (Stage 4). Results: Sixty patients with at least 1 follow-up TTE were included. The mean age was 73.5 +/- 11 years with 47% women (28/60) and median time of 381 days (IQR 12.7 months) between echocardiograms. On initial assessment, mean AVA and peak AV gradient were 1.2cm 2 +/- 0.33 and 37mmHg +/- 11.3 respectively. At follow-up, the mean AVA and peak AV gradient were 1.1cm 2 +/- 0.20 and 38mmHg +/- 12.6. Forty-three of 60 patients (72%) had evidence of cardiac damage on initial assessment compared to 55 of 60 patients (92%) on follow-up. Thirty-five (58%) patients displayed a decrease in peak AV gradient over time (average decrease -16% +/- 0.12). Twenty-one of the patients with declining peak gradients (60%) demonstrated progressive cardiac damage compared to 9 of 25 patients (36%) with increasing peak gradients (p= 0.06). Conclusions: Over half of patients with moderate AS demonstrated a decrease in peak AV gradient over time. Reliance on transvalvular gradients as a reflector of AS severity can be misleading as there was a trend toward more significant cardiac damage in this subset of patients. The presence of underlying cardiac damage can obscure traditional echocardiographic assessment and progression of AS and should be incorporated into assessments of disease severity and progression.

Measurement error in echocardiographic assessment of aortic stenosis: an epidemiological consideration of research methodology and clinical practice

Abstract Background/Introduction Current international guidelines on treatment of valvular heart disease contain recommendations for aortic valve replacement based exclusively on abnormal echocardiographic parameters in asymptomatic patients with aortic stenosis (AS). To prevent misclassification and subsequent mistreatment of patients, these recommendations require accurate and unbiased measurements of hemodynamic parameters. Purpose To illustrate consideration and impact of measurement error in echocardiographic assessment of aortic stenosis in both the research and clinical setting. Methods First, a systematic review was performed to investigate the recognition of and correction for measurement error in clinical studies on the prognostic value of peak aortic jet velocity (Vmax), mean pressure gradient (MPG), and effective orifice area (EOA). Second, all potential erroneous sources in the calculation of those primary parameters were listed stratified to random or systematic measurement error, and subsequently their magnitude was quantified. Third, the impact of various types of measurement error on current thresholds for intervention was graphically illustrated in different clinical scenarios. Results The presence of measurement error was acknowledged in 44% of the 36 included studies, while none utilized methods to correct for it. Interobserver variability ranged between 0.9–8.3% for Vmax and MPG but was substantially higher for EOA (range 7.7–12.7%) implying lower reliability (Figure 1). Furthermore, the invalid assumption of a circular left ventricular outflow tract area resulted in a median underestimation in EOA of 22.5% compared to 3D-transesophageal echocardiography (3D-TEE), computed tomography (CT), and cardiovascular magnetic resonance (CMR) planimetry. Figure 2 illustrates the impact of this discrepancy on the classification of AS using one-sided t-tests to determine the areas under the curve; the proportion of patients with non-severe AS in a hypothetical cohort (based on values from the PARTNER 3 trial [1[) increased by 42%. Conclusion(s) Measurement error is underrecognized in studies of echocardiographic assessment of aortic stenosis. This review demonstrates that random and systematic measurement errors affect echocardiographic assessment, leading to potential misdiagnosis and subsequent mistreatment. Clinicians and scientists should be aware of the implications of measurement errors to enhance rightful clinical decision-making and assure research validity. Funding Acknowledgement Type of funding sources: None.

Echocardiographic assessment of aortic stenosis: a practical guideline from the British Society of Echocardiography

The guideline provides a practical step-by-step guide in order to facilitate high-quality echocardiographic studies of patients with aortic stenosis. In addition, it addresses commonly encountered yet challenging clinical scenarios and covers the use of advanced echocardiographic techniques, including TOE and Dobutamine stress echocardiography in the assessment of aortic stenosis.

The five-beat averaged method of assessing aortic stenosis in atrial fibrillation significantly underestimates stenosis severity compared to sinus rhythm

Abstract Background Doppler echocardiographic assessment of aortic stenosis (AS) is dependent on trans-valvular flow rate (TVFR) and is most accurately performed in physiologically normal conditions (TVFR >200ml/s). Atrial fibrillation (AF) complicates AS assessment with heart rate variability and reduced averaged indexed stroke volume (SVi) compared to sinus rhythm (SR). We hypothesize that the 5-beat averaging technique in AF leads to underestimation of severity of AS compared to SR, and that diagnostic accuracy may be improved by maximum SVi beat selection. Methods Patients with at least mild AS (mean aortic gradient (MG) >15mmHg) with separate echocardiograms demonstrating SR and AF within a six-month period were identified. Patients with interval cardiac surgery, change in left ventricular ejection fraction (LVEF) of >15%, aortic valve prostheses, infective endocarditis, paced rhythm, severe concomitant valvular dysfunction, LVEF <35%, heart rate >100 beats per minute (bpm) or TVFR <200ml/s on their SR examination were excluded. In AF, individual beat SVi was calculated from individual beat aortic velocity time integral (VTI) and the reported aortic valve area (AVA) via the continuity equation. Results Seventeen patients were identified (mean time between echocardiograms 132 days, mean difference in LVEF 4%, mean difference in heart rate 11bpm). Using the 5-beat averaged model, compared to SR, the presence of AF significantly reduced SVi (−12.68ml/m2, p=0.00007) and TVFR (−69ml/s, p=0.00014). In AF, 9/17 cases demonstrated one or more beats with TVFR <200ml/s, with 6/17 producing a 5-beat averaged TVFR <200ml/s – consistent with a low flow state. Correspondingly, flow derived severity assessment parameters and calculated aortic valve area (AVA) in AF were reduced compared to SR (aortic peak velocity (Vmax) −0.42m/s, p=0.00005, MG −7.01mmHg, p=0.002, AVA −0.11cm2, p=0.025). As a proposed correction in AF, the single beat with the largest SVi was compared with SR. This measure improved concordance with flow conditions and severity assessment in SR (difference SVi −8.77ml/m2, p=0.004, TVFR −46ml/s, p=0.001, Vmax −0.21, p=0.003, MG −3.55mmHg, p=0.02) and equalized calculated AVA (−0.07cm2, p=0.09). Conclusion In individual patients with AS observed in SR and AF within a six-month period, AF was associated with significantly lower SVi and TVFR, with underestimation of AS severity assessment. AS assessment in AF using maximum observed stroke volume beat (as opposed to 5-beat average) improves concordance with SR assessment significantly. Funding Acknowledgement Type of funding source: None

Echocardiographic Assessment of Aortic Stenosis under Sedation Underestimates Stenosis Severity

Sedation can impact aortic stenosis (AS) classification, which depends on left ventricular ejection fraction (<≥ [less than or greater than and/or equal to] 50%), aortic valve area (AVA<≥ 1cm2), mean pressure gradient (<≥ 40mm Hg), peak velocity <≥ 400cm/sec, and stroke volume index (SVI <≥35mL/m2). We compared AS classification by transthoracic echo (TTE) during wakefulness versus sedation. Immediately following a baseline TTE performed during wakefulness, another TTE was done during sedation delivered for a concomitant transesophageal study in 69 consecutive patients with AS (mean age 78±7years, 32 males). AVA was calculated through the continuity equation using the relevant hemodynamic parameters measured by each TTE study and same left ventricular outflow tract. AS class was defined as moderate, severe high gradient (HG), low ejection fraction low flow low gradient (LF-LG), paradoxical LF-LG (PLFLG), and normal flow low gradient (NF-LG). Based on conservative versus invasive treatment implication, AS classes were aggregated into group A (moderate AS and NFLG) and group B (HG, low-EF LF-LG, and PLFLG). During sedation, systolic and diastolic blood pressure decreased by 14.3±29 and 8±22mm Hg, respectively, mean pressure gradient from 30.4±10.9 to 27.2±10.8mm Hg, peak velocity from 345.3±57.7 to 329.3±64.8cm/m2, and SVI from 41.5±11.3 to 38.3±11.8mL/m2 (all P<.05). Calculated AVA was similar (delta=-0.009±0.15cm2). Individual discrepancies in hemodynamic parameters between the paired TTE studies resulted in an overall 17.4% rate of AS intergroup misclassification with sedation, with a relative risk of 1.09 of downgrade misclassification from group B to A versus upgrade misclassification (P<.001). Sedation TTE assessment downgrades AS severity in a significant proportion of patients, with a conversely smaller proportion of patients being upgraded, and therefore cannot be a substitute for wakefulness assessment.

Real-World Echocardiographic Assessment of Aortic Stenosis: What Makes ‘Severe’ Severe?

Real-World Echocardiographic Assessment of Aortic Stenosis: What Makes ‘Severe’ Severe?

Resolving Apparent Inconsistencies Between Area, Flow, and Gradient Measurements in Patients With Aortic Valve Stenosis and Preserved Left Ventricular Ejection Fraction

Inconsistencies between area (aortic valve area [AVA])-flow-gradient are common during the echocardiographic assessment of aortic stenosis (AS). This study was conducted to investigate the importance of these inconsistencies and the impact of 3 methods to resolve these inconsistencies. The study population consisted of 327 patients (age: 76.3 ± 8.6 years, 49.5% males) with severe AS (SAS) (AVA ≤ 1 cm2) and preserved left ventricular ejection fraction (≥50%). Inconsistent findings between AVA, flow, and mean gradient (MG) were observed in 78 (23.9%) patients with low flow and a high MG, 52 (15.9%) patients with normal flow and a low MG, and 37 (11.3%) patients with a low flow and a low MG. Using stroke volume index by catheterization for AVA recalculation showed the greatest effect to resolve inconsistencies in the low flow and a high MG group (85%). Decreasing the AVA cut-off values for SAS to ≤0.8 cm2 resulted in a shift from SAS to moderate AS in 36 patients (69%) in the normal flow and a low MG. Indexing AVA to body surface area had only a minor impact on reclassification. In conclusion, in patients with SAS and preserved left ventricular ejection fraction, the majority of area-flow-gradient inconsistencies at echocardiography can be resolved by correcting errors in stroke volume index measurements by alternative techniques and by redefining the cut-off value for SAS to ≤0.8 cm2.

123 Doppler assessment of aortic stenosis: reading the peak velocity is superior to velocity time integral

IntroductionPrevious studies of the reproducibility of echocardiographic assessment of aortic stenosis have compared only a pair of observers. The aim of this study was to assess reproducibility across a large...

Challenges in the echocardiographic assessment of aortic stenosis.

Calcific aortic valve stenosis is common in the elderly. While history and examination can establish the diagnosis, determination of its severity typically requires echocardiography to define valve anatomy, measure stenosis severity and assess left ventricular response. The purpose of this review is to describe some of the commonly encountered challenges in the echocardiographic assessment of aortic stenosis. These include errors in the calculation of aortic valve area, assessment of aortic stenosis during atrial fibrillation, determining the presence of aortic stenosis in the setting of low transvalvular pressure gradients and discriminating other forms of obstruction to left ventricular ejection from aortic stenosis. Lastly, a review of how echocardiography is utilized to select patients for transcatheter aortic valve replacement is presented.

Transcatheter Aortic Valve Implantation in Patients With Concomitant Mitral and Tricuspid Regurgitation

The impact of atrioventricular valve regurgitation in patients who undergo transcatheter aortic valve implantation (TAVI) is not known. We examined the clinical outcome after TAVI in patients with moderate or more severe concomitant mitral or tricuspid regurgitation (TR). Two hundred sixty-eight consecutive patients who underwent TAVI at our institution since July 2007 were enrolled in this study. Patients had preoperative echocardiographic assessment of aortic stenosis and concomitant valve disease. At 6 months and 1 year, survival, New York Heart Association (NYHA) functional status, self-assessed state of health, and severity of mitral regurgitation (MR) and tricuspid regurgitation (TR) were assessed. Preoperatively, 22.4% of patients (60/268) had moderate or more severe MR, 20.1% (54/268) had moderate or more severe TR, and 9.3% (25/268) had moderate or more severe MR and TR. With moderate or more severe TR, 1 year all-cause mortality was significantly higher compared with that of mild or less severe TR (33.9% and 20.9%, respectively; log rank p = 0.028). With moderate or more severe MR, 1-year all-cause mortality was 30.2% compared with 21.2% in mild or less severe MR (log rank p = 0.068). Neither moderate or more severe MR nor TR emerged as an independent risk factor. At 6 months, heart failure symptoms were significantly reduced regardless of the extent of atrioventricular valve regurgitation. Sixty-seven percent of patients with moderate or more severe MR and 50% of patients with moderate or more severe TR had an improvement of valve regurgitation. Atrioventricular valve regurgitation is present in a subgroup of patients undergoing TAVI whose survival is impaired. The majority of surviving patients exhibit the clinical benefits of TAVI with amelioration of heart failure symptoms and a decrease in severity of atrioventricular valve regurgitation. At present, moderate or more severe atrioventricular valve regurgitation cannot be considered a contraindication for TAVI.

Atrial fibrillation in aortic stenosis - echocardiographic assessment and prognostic importance

BackgroundAtrial fibrillation (AFib) exists more frequently in patients with aortic stenosis (AS) than in patients without, and AFib may be a sign of progressive deterioration of AS. Echocardiographic assessment of AS in sinus rhythm is well documented, however, little is known about AFib in AS since such patients often are excluded from clinical echocardiographic trials.AimThe purpose of this study was to assess the prognostic importance of AFib in AS.MethodsThe study was designed as a single-center case-control study. Patients with AS and AFib were enrolled as cases (n = 103) and subsequently matched to controls (103 patients with AS but sinus rhythm). Cases and controls were matched according to age, gender and severity of AS. Primary outcome was all cause mortality and follow-up was 100% complete.ResultsCompared to controls the group with AFib had lower mean ejection fraction (42% vs. 49%; p < 0.001) and stroke volume (47 mL vs. 55 mL; p = 0.004), but higher heart rate (81 bpm vs. 68 bpm; p < 0.001) and no significant difference with regard to cardiac output (3.8 L vs. 4.0 L; p = 0.29). Accordingly, aortic jet velocity and gradients were significantly lower in AFib compared to controls but there were no differences (p = 0.38) in aortic valve area calculated by the continuity equation. During a median follow-up of 2.3 years (IQR: 1.2-3.6), 70 (34%) patients with AS died: 42 patients with AFib and 28 patients with sinus rhythm (p < 0.02). After adjusting for echocardiographic significant differences, AFib remained an independent predictor of mortality (HR 2.72 (95% CI: 1.12–6.61), p < 0.03). There was no significant interaction (p = 0.62) between AFib and AS on the risk of mortality, indicating that AFib predicted bad outcome regardless of the severity of AS.ConclusionsAFib is an independent risk factor in patients with AS and the prognostic impact of AFib seems to be the same despite the severity of AS.

Problem Is in the Subclinical Afterload Mismatch

REFER TO THE PAGE 79-84 In the era of aging society, prevalence of degenerative aortic stenosis (AS) increases rapidly.1) Systolic hypertension and widening of pulse pressure due to stiffened aorta are pathognomonic phenomenon in the elderly population.2) Compared to previous decades, echocardiographic evaluation of aortic valve become more convenient, accordingly incidence of newly diagnosed has increased markedly even in asymptomatic individuals.1) As degenerative is progressive disease in nature, monitoring by echocardiography provides crucial information in terms of decision making of surgical timing. Important clinical issues were raised by Hachicha et al.3) that increased could make low-flow severe in spite of preserved left ventricular (LV) ejection fraction, which is mainly by lower stroke volume index due to small LV cavity accompanied by increased LV mass to volume ratio and lower midwall fractional shortening. Accompanied with these geometrical changes, higher blood pressure and lower aortic compliance could result in low-gradient AS. Finally these structural and functional changes induce low-flow and low-gradient even in preserved LV ejection fraction. Important clinical finding was that these patients were associated with poorer outcome.3) Therefore, some concerns were raised about low-flow and low-gradient associated with high blood pressure and high global afterload. This is clinically important because currently trans-aortic valve pressure gradient and effective orifice area measured by continuous equation are choice of grading the severity. In addition, blood pressure changes time to time, especially in elderly individuals. Therefore if trans-aortic valve pressure gradient or effective orifice area changed significantly by blood pressure, it would be an important issue to be considered when monitoring the severity by echocardiography. To answer this question, Little et al.4) conducted a novel study regarding Impact of blood pressure on the Doppler echocardiographic assessment of AS by using hand grip exercise and phenylephrine infusion. In that study, they concluded that acute blood pressure elevation due to increased systemic vascular resistance can affect the Doppler-echo evaluation of severity. However, the impact of blood pressure on the assessment of severity depends primarily on the associated change in mean transvalvular flow rate, rather than on an independent effect of systemic vascular resistance or arterial compliance. This study shed light on dependency severity, but still raised another concern that How about pure effects of transient elevation without increase in heart rate?. This question is worthwhile to be answered because elevated systolic blood pressure in elderly population is usually not from increased sympathetic tone but from increased arterial stiffness caused by large artery fibrosis and calcification, therefore their blood pressure elevation usually is not accompanied by increased heart rate.5) Current paper by Chang et al.6) tried to answer this question by using pneumatic compression of both legs, which ideally elevate by increasing systemic vascular resistance and systolic blood pressure without impact on heart rate. They nicely showed effective orifice area of aortic valve was not significantly changed solely by transient elevation of afterload, therefore echocardiographic grading of severity would not be significantly affected by transient change. This is good news for physicians as we don't need to consider every hemodynamic status and don't need to seek any correction factors for blood pressure at every image acquisition. However, the both studies conducted by Little et al.4) and Chang et al.6) missed some important clinical issues long-term effects of persistently increased afterload or ventricular-afterload mismatch. Transient elevation of blood pressure by artificially modifying vascular tone is not usual clinical scenario, furthermore pneumatic compression also increases preload by augmenting venous return as suggested by increased in LV end-diastolic dimension and early mitral inflow velocity.6) Preload augmentation accompanied by increased contractility, which is not shown in this study, might compensate effects of elevation.7) Real hidden flaws are in the LV remodeling, preload and contractile reserve. Thickened myocardium associated with small LV cavity, decreased LV filling and impaired midwall fractional shortening altogether contribute to making low stroke volume associated with chronically elevated afterload. Then subclinical mismatch makes worse prognosis,3) therefore, current issue about problems should not be just focused on transiently elevated systolic blood pressure. We should not forget the real flaw is in the left ventricle. Incorporation of diastolic function, LV mass to volume ratio, midwall fractional shortening8) or velocity of circumferential myocardial fiber shortening possibly measured by speckle tracking echocardiography9) would be helpful in further stratifying the risk of patients with systemic hypertension.

Transesophageal echocardiographic scoring for transcatheter aortic valve implantation: Impact of aortic cusp calcification on postoperative aortic regurgitation

Transcatheter aortic valve implantation is an emerging technique for the treatment of aortic valve stenosis in high-risk patients. Detailed knowledge of aortic root anatomy, including specific information on the extent of native cusp calcifications, is required. The aim of this study was to evaluate whether echocardiographic assessment of aortic stenosis using a calcification score is useful to predict outcomes of transcatheter aortic valve implantation in elderly high-risk patients. Detailed preoperative digitalized transesophageal echocardiographic images were available from 103 patients treated by transapical transcatheter aortic valve implantation between February 2006 and February 2009. On the basis of a previously published study, an index score was developed to describe the extent of valve calcification ranging from 0 to 8 (normal to diffuse calcification). The median age of patients was 82.2 ± 5.9 years. The mean logistic European System for Cardiac Operative Risk Evaluation was 33.0% ± 16.3%. Mild paravalvular leak was present in 43 patients (42.2%), and a moderate paravalvular leak was observed in 5 patients (4.9%). Severe regurgitation was not observed in any patient. Logistic regression analysis revealed that the transcatheter aortic valve implantation echocardiographic calcification score is associated with the presence of moderate paravalvular aortic regurgitation (odds ratio, 8.5; 95% confidence interval, 1.2-58.9; P = .0001) and overall moderate aortic regurgitation (odds ratio, 3.6; 95% confidence interval, 1.2-10.4; P = .0006). Transesophageal echocardiography demonstrates detailed anatomic information of the calcification patterns of the aortic valve and root and thus plays an important role in the screening of patients undergoing transcatheter aortic valve implantation. The transcatheter aortic valve implantation echocardiographic calcification score allowed prediction of the risk of postoperative paravalvular and overall aortic regurgitation.

Rheumatic Mitral and Aortic Stenosis: To Replace or Not To Replace—That Is the Question—Part 2

Rheumatic Mitral and Aortic Stenosis: To Replace or Not To Replace—That Is the Question—Part 2

Echocardiographic Assessment of Aortic Stenosis in the Elderly

Aortic stenosis is one of the most common valvular conditions affecting the elderly population. This article reviews the echocardiographic assessment of aortic stenosis in the elderly including the advantages and limitations of different modalities and the potential role of 3-dimensional echocardiography in this special population.

Role of echocardiography in the diagnosis and treatment of patients with aortic stenosis.

Echocardiographic assessment plays a major role in the evaluation of aortic stenosis (AS). Because of its proven accuracy, ease of applicability, and safety, it is replacing cardiac catheterization for the assessment of AS in many centers. In this review, we discuss the basic principles of echocardiographic assessment of AS and clinically challenging scenarios including AS with low cardiac output state or other structural heart disease. Dobutamine stress echocardiography is a useful tool for assessing low cardiac output AS. The role of transesophageal echocardiography in the evaluation of AS is also reviewed. Echocardiographic techniques provide critical information in the assessment of patients with known or suspected AS and guide decision-making regarding the appropriateness of valve replacement.

An echocardiographic approach to the assessment of aortic stenosis

An accurate echocardiographic assessment of aortic stenosis is critical for the cost-effective diagnosis and management of patients with the clinical suspiciion of this diagnosis. Although the concepts involved in the echocardiographic determination of aortic pressure gradients and valve areas are relatively simple, acquisition of the data required to perform these calculations can at times be technically challenging. After reviewing the clinical signs and symptoms and the hemodynamics of aortic stenosis, this article reviews in detail the technical aspects involved in obtaining accurate gradients and valve areas emphasizing potential pitfalls.

Doppler echocardiographic assessment of aortic stenosis using the peak velocity ratio

Doppler echocardiographic assessment of aortic stenosis using the peak velocity ratio