Increasing mitral bridge width during M-TEER predicts greater reduction in mitral valve area (up to –4.0 ± 2.3 cm²) and higher increase in mean pressure gradient (p=0.02).
Does the total width of the M-TEER device bridge predict changes in mitral valve area and mean pressure gradient in patients undergoing M-TEER for severe mitral regurgitation?
The total width of the M-TEER device bridge is a significant predictor of post-procedural reductions in mitral valve area and increases in mean pressure gradient, which may aid in prospective device sizing.
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Abstract Background M-TEER is an effective minimally invasive treatment strategy for severe mitral regurgitation (MR). Variations in device sizing and mitral regurgitant anatomy can make predicting mitral valve haemodynamics post M-TEER challenging. Pre-operative valvular gradients and leaflet lengths are useful guides for device choice, however, don’t account for the impact of post TEER device size on residual functional mitral valve area and transvalvular gradients. Objectives This study aimed to assess the relationship between the total width of the M-TEER device "bridge" and subsequent absolute and relative changes in mitral valve area (MVA) (assessed by 3D multiplanar reconstruction (MPR)) and change in the mean pressure gradient (MPG). Methods A retrospective analysis over a 3-year period was conducted on consecutive patients undergoing M-TEER for both degenerative and functional MR from a single-centre quaternary hospital registry. A "mitral bridge width" was defined as the sum width of device clips (as defined by the device company) implanted post M-TEER. Philips Q-LAB version 10.8.5 was utilised for 3D reconstruction and MPR analysis for pre-procedural and post-procedural MVA. Valvular haemodynamics were quantified as per American Society of Echocardiography standardised guidelines. Statistics were performed in Microsoft excel version 16.94. Results A total of 65 patients underwent 66 M-TEER procedures. The mean age was 79 ± 8.2 years, 58.2% male, 42.4% had a left ventricular ejection fraction of 60%. As the mitral bridge width increased, there was a progressive decrease in the 3D MVA. The delta MVA with a bridge width of 4mm or 5mm, 6mm, 10mm and 12mm resulted in a decrease respectively of –1.6 ± 0.6 cm²; –2.8 ± 1.1 cm²; –3.9 ± 1.9 cm²; and –4.0 ± 2.3 cm² (p = 0.008) (Figure 1). When expressed as a percentage of the delta MVA, at a bridge width of 4mm or 5mm, 6mm, 10mm and 12mm there was a relative decrease in the MVA respectively of –37.9 ± 11.2%; –46.3 ± 11.5%; –56.1 ± 14.7%; and –52.5 ± 21.1% (p = 0.02) (Figure 2). The absolute value of the post procedural MPG was not significantly different between the bridge width groups (p=0.06). However, when corrected for delta MPG a significant intergroup difference was observed with greater increase in the MPG seen with an increasing bridge width (4 or 5mm = 5.8 ± 1.9 mmHg, 6mm = 3.2 ± 1.5 mmHg, 10mm = 4.4 ± 2.3 mmHg, 12mm= 4.2 ± 2.2 mmHg; p=0.02). Conclusions Pre-procedural mitral bridge width is a valuable predictor of delta MVA, the % delta MVA and the delta % of MPG in patients undergoing M-TEER. Utilising combined mitral bridge width prior to M-TEER implants may prospectively predict MVA and MPG for patients undergoing M-TEER.Figure 1 Figure 2
Thaw et al. (Sat,) reported a other. Increasing mitral bridge width during M-TEER predicts greater reduction in mitral valve area (up to –4.0 ± 2.3 cm²) and higher increase in mean pressure gradient (p=0.02).