Predictors of mitral annulus enlargement? A real-time three-dimensional transesophageal study

Atrial mitral regurgitation: Characteristics and outcomes of transcatheter mitral valve edge-to-edge repair

BACKGROUND

Mitral transcatheter edge-to-edge repair (MTEER) is an established therapeutic approach for mitral regurgitation (MR). Functional mitral regurgitation originating from atrial myopathy (A-FMR) has been described.

OBJECTIVES

We sought to assess the clinical, echocardiographic and hemodynamic considerations in A-FMR patients undergoing MTEER.

METHODS

From 2014 to 2020, patients undergoing MTEER for degenerative MR (DMR), functional MR (FMR), and mixed MR were assessed. A-FMR was defined by the presence of MR > moderate in severity; left ventricular (LV) ejection fraction (LVEF) ≥ 50%; and severe left atrial (LA) enlargement in the absence of LV dysfunction, leaflet pathology, or LV tethering. The diagnosis of A-FMR (vs. ventricular-FMR [V-FMR]) was confirmed by three independent echocardiographers. Baseline characteristics, procedural outcomes as well as clinical and echocardiographic follow-up are reported. Device success was defined as final MR grade ≤ moderate; MR reduction ≥1 grade; and final transmitral gradient <5 mmHg.

RESULTS

306 patients underwent MTEER, including DMR (62%), FMR (19%), and mixed MR (19%). FMR cases included 37 (63.8%) V-FMR and 21 (36.2%) A-FMR. Tricuspid regurgitation (≥ moderate) was higher in A-FMR (80.1%) compared to V-FMR (54%) and DMR (42%). Device success did not significantly differ between A-FMR and V-FMR (57% vs. 73%, p = 0.34) or DMR (57% vs. 64%, p = 1.0). The A-FMR cohort was less likely to achieve ≥3 grades of MR reduction compared to V-FMR (19% vs. 54%, p = 0.01) and DMR (19% vs. 49.7%, p = 0.01). Patients with V-FMR and DMR demonstrated significant reductions in mean left atrial pressure (LAP) and peak LA V-wave, though A-FMR did not (LAP -0.24 ± 4.9, p = 0.83; peak V-wave -1.76 ± 9.1, p = 0.39). In follow-up, echocardiographic and clinical outcomes were similar.

CONCLUSIONS

In patients undergoing MTEER, A-FMR represents one-third of FMR cases. A-FMR demonstrates similar procedural success but blunted acute hemodynamic responses compared with DMR and V-FMR following MTEER. Dedicated studies specifically considering A-FMR are needed to discern the optimal therapeutic approaches.

Progression of Mitral Regurgitation in Rheumatic Valve Disease: Role of Left Atrial Remodeling

Introduction

Mitral regurgitation (MR) is the most common valve abnormality in rheumatic heart disease (RHD) often associated with stenosis. Although the mechanism by which MR develops in RHD is primary, longstanding volume overload with left atrial (LA) remodeling may trigger the development of secondary MR, which can impact on the overall progression of MR. This study is aimed to assess the incidence and predictors of MR progression in patients with RHD.

Methods

Consecutive RHD patients with non-severe MR associated with any degree of mitral stenosis were selected. The primary endpoint was a progression of MR, which was defined as an increase of one grade in MR severity from baseline to the last follow-up echocardiogram. The risk of MR progression was estimated accounting for competing risks.

Results

The study included 539 patients, age of 46.2 ± 12 years and 83% were women. At a mean follow-up time of 4.2 years (interquartile range [IQR]: 1.2–6.9 years), 54 patients (10%) displayed MR progression with an overall incidence of 2.4 per 100 patient-years. Predictors of MR progression by the Cox model were age (adjusted hazard ratio [HR] 1.541, 95% CI 1.222–1.944), and LA volume (HR 1.137, 95% CI 1.054–1.226). By considering competing risk analysis, the direction of the association was similar for the rate (Cox model) and incidence (Fine-Gray model) of MR progression. In the model with LA volume, atrial fibrillation (AF) was no longer a predictor of MR progression. In the subgroup of patients in sinus rhythm, 59 had an onset of AF during follow-up, which was associated with progression of MR (HR 2.682; 95% CI 1.133–6.350).

Conclusions

In RHD patients with a full spectrum of MR severity, progression of MR occurs over time is predicted by age and LA volume. LA enlargement may play a role in the link between primary MR and secondary MR in patients with RHD.