Accuracy of the flow convergence method for quantification of aortic regurgitation in patients with central versus eccentric jets

Echocardiographic assessment of aortic regurgitation: a narrative review

Aortic regurgitation (AR) is the third most frequently encountered valve lesion and may be caused by abnormalities of the valve cusps or the aorta. Echocardiography is instrumental in the assessment of AR as it enables the delineation of valvular morphology, the mechanism of the lesion and the grading of severity. Severe AR has a major impact on the myocardium and carries a significant risk of morbidity and mortality if left untreated. Established and novel echocardiographic methods, such as global longitudinal strain and three-dimensional echocardiography, allow an estimation of this risk and provide invaluable information for patient management and prognosis. This narrative review summarises the epidemiology of AR, reviews current practices and recommendations with regards to the echocardiographic assessment of AR and outlines novel echocardiographic tools that may prove beneficial in patient assessment and management.

Aortic regurgitation: A multimodality approach

Aortic regurgitation (AR) is a common valvular pathology. Multimodality noninvasive cardiovascular imaging is routinely used to assess the mechanism of AR, degree, and its hemodynamic impact on the cardiovascular system. Collecting this information is crucial in establishing the prognosis and in guiding patient management and follow-up. While echocardiography remains the primary test to assess AR, a comprehensive assessment of this valvulopathy can be obtained by combining the information from different techniques. This state-of-the-art review is intended to provide an update ed overview of the applications, strengths, and limits of transthoracic echocardiography, cardiac magnetic resonance, and cardiac computed tomography in patients with AR.

Role of Cardiovascular Magnetic Resonance in Native Valvular Regurgitation: A Comprehensive Review of Protocols, Grading of Severity, and Prediction of Valve Surgery

Valvular regurgitation is common in developed countries with an increasing prevalence due to the aging of the population and more accurate diagnostic imaging methods. Echocardiography is the gold standard method for the assessment of the severity of valvular heart regurgitation. Nonetheless, cardiovascular magnetic resonance (CMR) has emerged as an additional tool for assessing mainly the severity of aortic and mitral valve regurgitation in the setting of indeterminate findings by echocardiography. Moreover, CMR is a valuable imaging modality to assess ventricular volume and flow, which are useful in the calculation of regurgitant volume and regurgitant fraction of mitral valve regurgitation, aortic valve regurgitation, tricuspid valve regurgitation, and pulmonary valve regurgitation. Notwithstanding this, reference values and optimal thresholds to determine the severity and prognosis of valvular heart regurgitation have been studied lesser by CMR than by echocardiography. Hence, further larger studies are warranted to validate the potential prognostic relevance of the severity of valvular heart regurgitation determined by CMR. The present review describes, analyzes, and discusses the use of CMR to determine the severity of valvular heart regurgitation in clinical practice.

Quantification of chronic aortic regurgitation using left and right ventricular stroke volumes obtained from two new automated three-dimensional transthoracic echocardiographic software: feasibility and accuracy

The present study aimed to evaluate the feasibility and accuracy of chronic aortic regurgitation (CAR) quantification using left and right ventricular stroke volumes (LVSV and RVSV, respectively) obtained from two new automated three-dimensional transthoracic echocardiographic software-Dynamic HeartModel (DHM) and 3D Auto RV. Patients (n=116) with more than mild isolated CAR were included and divided into two groups: central (n=53) and eccentric CAR (n=63) groups. LVSV and RVSV were automatically measured by DHM and 3D Auto RV. Next, aortic regurgitant volume (ARVol) was calculated three ways: as the difference between LVSV and RVSV, by the two-dimensional proximal isovelocity surface area (PISA) method, and using effective regurgitant orifice area derived from real-time three-dimensional echocardiography (RT3DE) multiplied by CAR velocity time integral (the reference standard). DHM plus 3D Auto RV correlated well with RT3DE in ARVol measurement in both groups (central, r = 0.90; eccentric, r = 0.96), with no significant difference based on consistency analysis. In the eccentric group, PISA led to an obvious underestimation (mean difference= - 4.20 ml, P < 0.05). The kappa agreement between DHM plus 3D Auto RV and RT3DE in grading CAR severity in both groups was good (central, k = 0.89; eccentric, k = 0.86), but that between PISA and RT3DE in the eccentric CAR group was suboptimal (k = 0.74). This study indicates that ARVol quantification using DHM plus 3D Auto RV is feasible and reproducible in patients with more than mild isolated CAR. This new method has great correlation and agreement with RT3DE in ARVol measurement, with evident advantages over PISA in eccentric CAR.

Multi-modality imaging assessment of native valvular regurgitation: an EACVI and ESC council of valvular heart disease position paper

Valvular regurgitation represents an important cause of cardiovascular morbidity and mortality. Imaging is pivotal in the evaluation of native valve regurgitation and echocardiography is the primary imaging modality for this purpose. The imaging assessment of valvular regurgitation should integrate quantification of the regurgitation, assessment of the valve anatomy and function, and the consequences of valvular disease on cardiac chambers. In clinical practice, the management of patients with valvular regurgitation largely relies on the results of imaging. It is crucial to provide standards that aim at establishing a baseline list of measurements to be performed when assessing native valve regurgitation. The present document aims to present clinical guidance for the multi-modality imaging assessment of native valvular regurgitation.

Grading of aortic regurgitation by cardiovascular magnetic resonance and pulsed Doppler of the left subclavian artery: harmonizing grading scales between imaging modalities

Transthoracic echocardiography (TTE) and cardiac magnetic resonance (CMR) are current standard for assessing aortic regurgitation (AR). Regurgitant fraction (RF) can also be estimated by Doppler examination of the left subclavian artery (LSA-Doppler). However, a comparison of AR grading scales using these methods and a TTE multiparametric approach as reference is lacking. We evaluated the severity of AR in 73 patients (58 ± 15 years; 57 men), with a wide spectrum of AR of the native valve. Using a recommended TTE multiparametric approach the AR was divided in none/trace (n = 12), mild (n = 23), moderate (n = 12), and severe (n = 26). RF was evaluated by LSA-Doppler (ratio between diastolic and systolic velocity–time integrals) and by CMR phase-contrast imaging (performed in the aorta 1 cm above the aortic valve); the grading scales were then calculated. There were a good correlation between all methods, but mean RF values were greater with TTE compared with LSA-Doppler and CMR (39 ± 16% vs. 35 ± 18% vs. 32 ± 20%, respectively; p < 0.037). Mean differences in RF values between methods were significant in the groups with mild and moderate AR. Grading scales that best defined the TTE derived AR severity using CMR were: mild, < 21%; moderate, 22 to 41%; and severe, > 42%; and using LSA-Doppler: mild, < 29%; moderate, 30 to 44%; and severe, > 45%. RF values for AR grading using TTE, LSA-Doppler and CMR correlate well but differ in groups with mild and moderate AR when using a recognized multiparametric echocardiographic approach. Clinical prospective studies should validate these proposed modality adjusted grading scales.

Quantitative assessment of aortic regurgitation by Doppler echocardiography: Usefulness of the comparison of aortic and pulmonary flows

AIMS

Patients with significant (3+/4+) aortic regurgitation (AR) require careful monitoring or valve surgery. We sought to evaluate the diagnostic performance of aortic and pulmonary flow comparison in identifying patients with significant AR, by echocardiography.

METHOD

Two hundred forty-six patients with more than trivial AR were prospectively enrolled from three centers. Aortic regurgitation (AR) severity was assessed by an expert using the currently recommended integrative approach. Aortic and pulmonary flows were independently assessed by another investigator to calculate the regurgitant fraction (RF), the aortic to pulmonary flow ratio (Qao/Qp) and the aortic to pulmonary velocity-time integral (VTIao/VTIp) ratio. The control group consisted of 195 patients without AR.

RESULTS

A significant correlation was observed between AR grading and RF (r = .82, P < .0001) and Qao/Qp (r = .81, P < .0001), but the correlation was modest for VTIao/VTIp ratio (r = .63; P < .0001). The accuracy of RF and Qao/Qp ratio to identify patients with significant AR was excellent (0.96 and 0.95, respectively), but was significantly lower for VTIao/VTIp ratio at 0.82. A RF > 40% indicated grade 3 or 4 AR with a sensitivity of 83% and a specificity of 93%. A Qao/Qp ratio > 1.6 indicated grade 3 or 4 AR with a sensitivity of 88% and a specificity of 89%. The VTIao/VTIp ratio was not helpful in identifying patients with significant AR, as a wide overlap was found between 1+/2+ and 3+/4+ patients.

CONCLUSION

Regurgitant fraction (RF) and Qao/Qp are helpful in identifying significant AR. The assessment of Doppler aortic/pulmonary flow should be incorporated in the comprehensive evaluation of AR.

Automatic quantification of aortic regurgitation using 3D full volume color doppler echocardiography: a validation study with cardiac magnetic resonance imaging

Recent advances in real-time three-dimensional (3D) echocardiography provide the automated measurement of mitral inflow and aortic stroke volume without the need to assume the geometry of the heart. The aim of this study is to explore the ability of 3D full volume color Doppler echocardiography (FVCDE) to quantify aortic regurgitation (AR). Thirty-two patients with more than a moderate degree of AR were enrolled. AR volume was measured by (1) two-dimensional-CDE, using the proximal isovelocity surface area (PISA) and (2) real-time 3D-FVCDE with (3) phase-contrast cardiac magnetic resonance imaging (PC-CMR) as the reference method. Automated AR quantification using 3D-FVCDE was feasible in 30 of the 32 patients. 2D-PISA underestimated the AR volume compared to 3D-FVCDE and PC-CMR (38.6 ± 9.9 mL by 2D-PISA; 49.5 ± 10.2 mL by 3D-FVCDE; 52.3 ± 12.6 mL by PC-CMR). The AR volume assessed by 3D-FVCDE showed better correlation and agreement with PC-CMR (r = 0.93, p < 0.001, 2SD: 9.5 mL) than did 2D-PISA (r = 0.76, p < 0.001, 2SD: 15.7 mL). When used to classify AR severity, 3D-FVCDE agreed better with PC-CMR (k = 0.94) than did 2D-PISA (k = 0.53). In patients with eccentric jets, only 30% were correctly graded by 2D-PISA. Conversely, almost all patients with eccentric jets (86.7%) were correctly graded by 3D-FVCDE. In patients with multiple jets, only 3 out of 10 were correctly graded by 2D-PISA, while 3D-FVCDE correctly graded 9 out of 10 of these patients. Automated quantification of AR using the 3D-FVCDE method is clinically feasible and more accurate than the current 2D-based method. AR quantification by 2D-PISA significantly misclassified AR grade in patients with eccentric or multiple jets. This study demonstrates that 3D-FVCDE is a valuable tool to accurately measure AR volume regardless of AR characteristics.

Members of the receptor for advanced glycation end products axis as potential therapeutic targets in patients with lupus nephritis

The relationship of inflammation and the expression of full-length receptor for advanced glycation end products (flRAGE) on monocytes, plasma levels of RAGE ligand high mobility group box protein 1 (HMGB1), soluble RAGE (sRAGE) and endogenous secretory RAGE (esRAGE) was assessed to elucidate the effect of HMGB1/DNA/RAGE-mediated innate inflammatory responses in patients with lupus nephritis. Cell surface expression of flRAGE was elevated on the monocytes of lupus patients, correlated with plasma HMGB1 levels. Plasma sRAGE level negatively correlated with systemic lupus erythematosus (SLE) disease activity index. Plasma esRAGE level was significantly lower in SLE patients with flare while esRAGE/sRAGE ratio negatively correlated with complement C3 level. HMGB1 alone could moderately induce ex vivo IL-6 production from monocytes, resulting in activation of intracellular p38 mitogen-activated protein kinase (MAPK), c-Jun N-terminal kinase and nuclear factor (NF)-κB. Moreover, toll-like receptor-9 ligand together with HMGB1 exhibited a synergistic effect on IL-6 and IL-12p70 secretions and the phosphorylation of p38 MAPK and NF-κB. Therefore, over-expression of flRAGE in lupus may lead to the amplification of RAGE ligands-mediated inflammatory responses through the activation of p38 MAPK and NF-κB. Plasma sRAGE may serve as a potential biomarker for disease activity and a future therapeutic target in SLE.

[Planimetric measurement of the regurgitant orifice area using tridimensional transoesophageal echocardiography for aortic regurgitation, reproducibility and feasibility]

BACKGROUND

Aortic regurgitation is mainly evaluated by trans-thoracic echocardiography using multi-parametric qualitative and semi quantitative tools. All those parameters can fail to meet expectations, resulting in an imperfect diagnostic reliability and assessment of aortic regurgitation severity can be challenging.

OBJECTIVES

We sought to evaluate feasibility and intra- and inter-observer reproducibility of aortic regurgitant orifice area measured by planimetry with tridimensional trans-esophageal echocardiography on patients with at least grade 2/4 aortic regurgitation.

PATIENTS AND METHODS

Consecutive patients with at least grade 2/4 aortic regurgitation measured by trans-thoracic echocardiography and referred for trans-esophageal echocardiography for any reason were included. Planimetric reconstructions of regurgitant orifice area were studied and reproducibility indexes between senior and junior observers were calculated.

RESULTS

Twenty-three patients were included in this study. Intra- and inter-observer reproducibility were excellent with an ICC of 0.95 [0.88-0.98], P<0.0001 and 0.91 [0.79-0.96], P<0.0001, respectively. Mean length of the measurement was 6.6±0.9min [CI95% 6.23-7.01].

CONCLUSION

Planimetric measurement of the aortic regurgitant orifice using tridimensional trans-esophageal echocardiography seems to be feasible and has great intra- and inter-observer reproducibility. Reconstruction durations were compatible with a daily use. There is a need now to investigate the reliability of this measurement as compared with the reference technique.

The alarmin functions of high-mobility group box-1 and IL-33 in the pathogenesis of systemic lupus erythematosus

'Alarmins' are a group of endogenous proteins or molecules that are released from cells during cellular demise to alert the host innate immune system. Two of them, high-mobility group box-1 (HMGB1) and IL-33 shared many similarities of cellular localization, functions and involvement in various inflammatory diseases including systemic lupus erythematosus (SLE). The expressions of HMGB1 and IL-33, and their corresponding receptors RAGE (receptor for advanced glycation end products) and ST2, respectively, are substantially upregulated in patients with lupus nephritis (LN). This review highlights the emerging roles of alarmin proteins in various pathologies of LN, by focusing on classical HMGB1 and a newly discovered alarmin IL-33.

Accuracy of three-dimensional versus two-dimensional echocardiography for quantification of aortic regurgitation and validation by three-dimensional three-directional velocity-encoded magnetic resonance imaging

Quantitative assessment of aortic regurgitation (AR) remains challenging. The present study evaluated the accuracy of 2-dimensional (2D) and 3-dimensional (3D) transthoracic echocardiography (TTE) for AR quantification, using 3D 3-directional velocity-encoded magnetic resonance imaging (VE-MRI) as the reference method. Thirty-two AR patients were included. With color Doppler TTE, 2D effective regurgitant orifice area (EROA) was calculated using the proximal isovelocity surface area method. From the 3D TTE multiplanar reformation data, 3D-EROA was calculated by planimetry of the vena contracta. Regurgitant volumes (RVol) were obtained by multiplying the 2D-EROA and 3D-EROA by the velocity-time integral of AR jet and compared with that obtained using VE-MRI. For the entire population, 3D TTE RVol demonstrated a strong correlation and good agreement with VE-MRI RVol (r = 0.94 and -13.6 to 15.6 ml/beat, respectively), whereas 2D TTE RVol showed a modest correlation and large limits of agreement with VE-MRI (r = 0.70 and -22.2 to 32.8 ml/beat, respectively). Eccentric jets were noted in 16 patients (50%). In these patients, 3D TTE demonstrated an excellent correlation (r = 0.95) with VE-MRI, a small bias (0.1 ml/beat) and narrow limits of agreement (-18.7 to 18.8 ml/beat). Finally, the kappa agreement between 3D TTE and VE-MRI for grading of AR severity was good (k = 0.96), whereas the kappa agreement between 2D TTE and VE-MRI was suboptimal (k = 0.53). In conclusion, AR RVol quantification using 3D TTE is accurate, and its advantage over 2D TTE is particularly evident in patients with eccentric jets.

Recommendations for the echocardiographic assessment of native valvular regurgitation: an executive summary from the European Association of Cardiovascular Imaging

Valvular regurgitation represents an important cause of cardiovascular morbidity and mortality. Echocardiography has become the primary non-invasive imaging method for the evaluation of valvular regurgitation. The echocardiographic assessment of valvular regurgitation should integrate the quantification of the regurgitation, assessment of the valve anatomy and function, as well as the consequences of valvular disease on cardiac chambers. In clinical practice, the management of patients with valvular regurgitation thus largely integrates the results of echocardiography. It is crucial to provide standards that aim at establishing a baseline list of measurements to be performed when assessing regurgitation.

A practical guide to multimodality imaging of transcatheter aortic valve replacement

The advent of transcatheter aortic valve replacement (TAVR) is one of the most widely anticipated advances in the care of patients with severe aortic stenosis. This procedure is unique in many ways, one of which is the need for a multimodality imaging team-based approach throughout the continuum of the care of TAVR patients. Pre-procedural planning, intra-procedural implantation optimization, and long-term follow-up of patients undergoing TAVR require the expert use of various imaging modalities, each of which has its own strengths and limitations. Divided into 3 sections (pre-procedural, intraprocedural, and long-term follow-up), this review offers a single source for expert opinion and evidence-based guidance on how to incorporate the various modalities at each step in the care of a TAVR patient. Although much has been learned in the short span of time since TAVR was introduced, recommendations are offered for clinically relevant research that will lead to refinement of best practice strategies for incorporating multimodality imaging into TAVR patient care.

Quantification of chronic aortic regurgitation by vector flow mapping: a novel echocardiographic method

AIMS

Quantification of aortic regurgitation (AR) using echocardiography is challenging. A newly established echocardiographic method, vector flow mapping (VFM), can directly measure blood flow volume (FV) regardless of rheological characteristics. We intended to assess the accuracy of VFM in the quantification of chronic AR.

METHODS AND RESULTS

Twenty-one patients with chronic AR, along with 21 healthy volunteers selected as controls, underwent conventional echocardiography and estimation of aortic blood flow using quantitative Doppler and VFM. The regurgitation ratio (RegR), derived as the quotient of backward and forward aortic FV in the ascending aorta measured by VFM, increased with AR severity: 1.1 +/- 1.5% (normal), 11.4 +/- 3.8% (mild AR), 31.2 +/- 8.0% (moderate AR), and 59.3 +/- 4.7% (severe AR). In a linear regression model, RegR closely correlated with the VC width (r = 0.932) and regurgitation fraction and effective regurgitant orifice measured by the quantitative Doppler method (r = 0.929 and 0.891, respectively). The intra- and interobserver variability of RegR was 4.2 and 6.7%, respectively. There was no difference between RegR measured in the apical five-chamber view and in that in apical three-chamber view using the paired t-test (P = 0.751).

CONCLUSION

RegR measured by VFM, a new Doppler method allowing quantitative analysis of FV in spite of the presence of turbulent flow, is a highly reproducible parameter with good accuracy for AR quantification.