Prognostic impact of peak mitral inflow velocity in asymptomatic degenerative mitral regurgitation

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.

Three-dimensional echocardiography for predicting mitral stenosis after MitraClip for functional mitral regurgitation

BACKGROUND

Postprocedural mitral stenosis (MS), or increased transmitral mean pressure gradient (TMPG), is one of the limitations of transcatheter edge-to-edge mitral valve repair using MitraClip (Abbott Vascular Inc., Santa Clara, USA); however, the usefulness of three-dimensional transesophageal echocardiography (3D-TEE) for predicting postprocedural MS in functional mitral regurgitation (MR) has not been fully elucidated.

METHODS

Eighty-two consecutive functional MR patients who underwent transcatheter mitral valve repair using MitraClip were retrospectively studied. Postprocedural MS was defined as TMPG ≥ 5 mmHg by echocardiography.

RESULTS

Ten patients had postprocedural MS, and 3D-TEE showed that patients with postprocedural MS had smaller preprocedural mitral valve orifice area (MVOA), anteroposterior and mediolateral diameter, leaflet area, and annulus area. Receiver operating characteristic analysis showed that leaflet area (area under the curve (AUC) 0.829), annulus area (AUC 0.813), anteroposterior diameter (AUC 0.797) and mediolateral diameter (AUC 0.803) evaluated using 3D-TEE were predictors of postprocedural MS, and their predictive abilities were higher than those of preprocedural MVOA (AUC 0.756) and preprocedural TMPG (AUC 0.716). Adding leaflet area to TMPG and MVOA resulted in higher C-statistics for predicting postprocedural MS (from 0.716 to 0.845 and from 0.756 to 0.853, respectively).

CONCLUSIONS

In functional MR patients treated with MitraClip, leaflet area and annulus area evaluated using 3D-TEE had high predictive values for postprocedural MS, and their predictive abilities were higher than those of preprocedural TMPG or MVOA.

Prognostic comparison of atrial and ventricular functional mitral regurgitation

Objective

Atrial functional mitral regurgitation (A-FMR) has been suggested as a new aetiology of functional MR (MR); however, its prognosis and prognostic predictors are not fully elucidated. Aim of this study was to investigate the prognosis and prognostic predictors of A-FMR in comparison with ventricular functional MR (V-FMR).

Methods

Three hundred and seventy-eight consecutive patients with moderate-to-severe or severe functional MR were studied. Functional MR was classified into V-FMR (N=288) and A-FMR (N=90) depending on the alterations of left ventricle (LV) or left atrium (LA) along with clinical context and diagnosis of ischaemic heart disease or cardiomyopathy.

Results

During a median follow-up of 4.1 (2.0–6.7) years, all-cause mortality, cardiovascular mortality and heart failure (HF) hospitalisation occurred in 98 (26%), 81 (21%) and 177 (47%) patients, respectively, and rates of these events and the composite end point of all-cause mortality and HF hospitalisation were consistently higher in V-FMR than A-FMR (unadjusted HR 1.762 (95% CI 1.250 to 2.438), p<0.001; adjusted HR 1.654 (95% CI 1.027 to 2.664), p=0.038, for the composite end point). Further analysis showed different prognostic predictors between V-FMR and A-FMR; while age and LA volume index were independent prognostic predictors of both V-FMR and A-FMR, systolic blood pressure and B-type natriuretic peptide were also those of V-FMR, and estimated glomerular filtration rate, LV end-systolic dimension and tricuspid regurgitation were also those of A-FMR.

Conclusions

The prognosis of V-FMR was significantly worse than that of A-FMR, and prognostic predictors were different between V-FMR and A-FMR. Our study suggests the importance of discriminating A-FMR and V-FMR, and that different treatment strategies may be considered for each aetiology.