Reproducibility of reading echocardiographic parameters to assess severity of mitral regurgitation. Insights from a French multicentre study

Quantification of primary mitral regurgitation by echocardiography: A practical appraisal

The accurate quantification of primary mitral regurgitation (MR) and its consequences on cardiac remodeling is of paramount importance to determine the best timing for surgery in these patients. The recommended echocardiographic grading of primary MR severity relies on an integrated multiparametric approach. It is expected that the large number of echocardiographic parameters collected would offer the possibility to check the measured values regarding their congruence in order to conclude reliably on MR severity. However, the use of multiple parameters to grade MR can result in potential discrepancies between one or more of them. Importantly, many factors beyond MR severity impact the values obtained for these parameters including technical settings, anatomic and hemodynamic considerations, patient's characteristics and echocardiographer' skills. Hence, clinicians involved in valvular diseases should be well aware of the respective strengths and pitfalls of each of MR grading methods by echocardiography. Recent literature highlighted the need for a reappraisal of the severity of primary MR from a hemodynamic perspective. The estimation of MR regurgitation fraction by indirect quantitative methods, whenever possible, should be central when grading the severity of these patients. The assessment of the MR effective regurgitant orifice area by the proximal flow convergence method should be used in a semi-quantitative manner. Furthermore, it is crucial to acknowledge specific clinical situations in MR at risk of misevaluation when grading severity such as late-systolic MR, bi-leaflet prolapse with multiple jets or extensive leak, wall-constrained eccentric jet or in older patients with complex MR mechanism. Finally, it is debatable whether the 4-grades classification of MR severity would be still relevant nowadays, since the indication for mitral valve (MV) surgery is discussed in clinical practice for patients with 3+ and 4+ primary MR based on symptoms, specific markers of adverse outcome and MV repair probability. Primary MR grading should be seen as a continuum integrating both quantification of MR and its consequences, even for patients with presumed "moderate" MR.

Comparison of effective regurgitant orifice area by the PISA method and tricuspid coaptation gap measurement to identify very severe tricuspid regurgitation and stratify mortality risk

Introduction

Various definitions of very severe (VS) tricuspid regurgitation (TR) have been proposed based on the effective regurgitant orifice area (EROA) or tricuspid coaptation gap (TCG). Because of the inherent limitations associated with the EROA, we hypothesized that the TCG would be more suitable for defining VSTR and predicting outcomes.

Materials and methods

In this French multicentre retrospective study, we included 606 patients with ≥moderate-to-severe isolated functional TR (without structural valve disease or an overt cardiac cause) according to the recommendations of the European Association of Cardiovascular Imaging. Patients were further stratified into VSTR according to the EROA (≥60 mm²) and then according to the TCG (≥10 mm). The primary endpoint was all-cause mortality and the secondary endpoint was cardiovascular mortality.

Results

The relationship between the EROA and TCG was poor (R²=0.22), especially when the size of the defect was large. Four-year survival was comparable between patients with an EROA <60 mm² vs. ≥60 mm² (68 ± 3% vs. 64 ± 5%, p = 0.89). A TCG ≥10 mm was associated with lower four-year survival than a TCG <10 mm (53 ± 7% vs. 69 ± 3%, p < 0.001). After adjustment for covariates, including comorbidity, symptoms, dose of diuretics, and right ventricular dilatation and dysfunction, a TCG ≥10 mm remained independently associated with higher all-cause mortality (adjusted HR[95% CI] = 1.47[1.13-2.21], p = 0.019) and cardiovascular mortality (adjusted HR[95% CI] = 2.12[1.33-3.25], p = 0.001), whereas an EROA ≥60 mm² was not associated with all-cause or cardiovascular mortality (adjusted HR[95% CI]: 1.16[0.81-1.64], p = 0.416, and adjusted HR[95% CI]: 1.07[0.68-1.68], p = 0.784, respectively).

Conclusion

The correlation between the TCG and EROA is weak and decreases with increasing defect size. A TCG ≥10 mm is associated with increased all-cause and cardiovascular mortality and should be used to define VSTR in isolated significant functional TR.

The Role of Stress Echocardiography in Valvular Heart Disease

PURPOSE OF REVIEW

Stress echocardiography is recommended in valvular heart disease when there is a mismatch between resting transthoracic echocardiography findings and symptoms during activities of daily living. We describe the current methodology and the evidence supporting these applications.

RECENT FINDINGS

The comprehensive stress echo assessment includes valve function (gradients and regurgitation), left ventricular global systolic and diastolic function, left atrial volume, pulmonary congestion, pulmonary arterial pressure, and right ventricular function, integrated with blood pressure response with cuff sphygmomanometer, chronotropic reserve with heart rate, and symptoms. Recent guidelines recommend the evaluation of asymptomatic severe or symptomatic non-severe mitral regurgitation or stenosis with exercise stress and suspected low-flow, low-gradient severe aortic stenosis with reduced ejection fraction with low dose (up to 20 mcg, without atropine) dobutamine stress. Prospective, large-scale studies based on a comprehensive protocol (ABCDE +) capturing the multiplicity of clinical phenotypes are needed to support stress echo-driven treatment strategies.

Reproducibility of the 2016 American Society of Echocardiography-European Association of Cardiovascular Imaging Algorithm for Estimation of Left Ventricular Filling Pattern: Not Perfect but Good Enough

The 2016 American Society of Echocardiography (ASE) and European Association of Cardiovascular Imaging (EACVI) guidelines for the evaluation of left ventricular diastolic function reported a new algorithm to assess diastolic function and to estimate left ventricular filling pressure (LVFP). At least five to six different parameters were necessary to conclude, each of them with their own inter-observer variability. This article examines the reproducibility of each parameter of the algorithm and its influence on the final decision of the clinician. Echocardiographic exams of 12 non-selected patients without any known cardiac disease or follow-up but addressed to the hospital for symptoms were analyzed by two readers (one junior and one senior) in five French cardiologic tertiary centers. Inter-observer reproducibility at each step of the algorithm and final decision were analyzed. There was mild agreement on the final decision. The main reasons of discrepancy were disagreement on the significance of mitral annular calcifications and measured values that are just around the cut-off (despite good reproducibility, a slight variation could lead to misclassification of a dichotomous choice between a normal measure and a pathologic measure). Without considering performance, this multicentric French study puts forward limits to the actual algorithm recommended for LVFP pattern assessment. Agreement is excellent in caricatural (easy) cases (left ventricular pressure clearly normal or clearly elevated) but a great discordance exists in the gray zone. Improvement in the algorithm and in the method for LVFP determination is proposed.