Clinical Investigations
Echocardiography and Transcatheter Edge-to-Edge Repair
Transcatheter Edge-to-Edge Repair in Proportionate Versus Disproportionate Functional Mitral Regurgitation

https://doi.org/10.1016/j.echo.2021.08.002Get rights and content
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Highlights

  • Transcatheter treatment of FMR is a subject of debate.

  • Proportionality of EROA to LV volumes could influence the outcome of TEER.

  • Disproportionate mitral regurgitation showed greater reduction after TEER.

  • A substantial part of initial FMR reduction deteriorated during follow-up.

  • Clinical outcomes at 2 years did not differ between different proportionality groups.

Background

Functional mitral regurgitation (FMR) can be subclassified on the basis of its proportionality relative to left ventricular (LV) volume and function, indicating potential differences in underlying etiology. The aim of this study was to evaluate the association of FMR proportionality with FMR reduction, heart failure hospitalization and mortality after transcatheter edge-to-edge mitral valve repair (TEER).

Methods

This multicenter registry included 241 patients with symptomatic heart failure with reduced LV ejection fraction treated with TEER for moderate to severe or greater FMR. FMR proportionality was graded on preprocedural transthoracic echocardiography using the ratio of the effective regurgitant orifice area to LV end-diastolic volume. Baseline characteristics, follow-up transthoracic echocardiography, and 2-year clinical outcomes were compared between groups.

Results

Median LV ejection fraction, effective regurgitant orifice area and LV end-diastolic volume index were 30% (interquartile range [IQR], 25%–35%), 27 mm2, and 107 mL/m2 (IQR, 90–135 mL/m2), respectively. Median effective regurgitant orifice area/LV end-diastolic volume ratio was 0.13 (IQR, 0.10–0.18). Proportionate FMR (pFMR) and disproportionate FMR (dFMR) was present in 123 and 118 patients, respectively. Compared with patients with pFMR, those with dFMR had higher baseline LV ejection fractions (median, 32% [IQR, 27%–39%] vs 26% [IQR, 22%–33%]; P < .01). Early FMR reduction with TEER was more pronounced in patients with dFMR (odds ratio, 0.45; 95% CI, 0.28–0.74; P < .01) than those with pFMR, but not at 12 months (odds ratio, 0.93; 95% CI, 0.53–1.63; P = .80). Overall, in 35% of patients with initial FMR reduction after TEER, FMR deteriorated again at 1-year follow-up. Rates of 2-year all-cause mortality and heart failure hospitalization were 30% (n = 66) and 37% (n = 76), with no differences between dFMR and pFMR.

Conclusions

TEER resulted in more pronounced early FMR reduction in patients with dFMR compared with those with pFMR. Yet after initial improvement, FMR deteriorated in a substantial number of patients, calling into question durable mitral regurgitation reductions with TEER in selected patients. The proportionality framework may not identify durable TEER responders.

Keywords

Functional mitral regurgitation
Edge-to-edge mitral valve repair
Heart failure

Abbreviations

COAPT
Cardiovascular Outcomes Assessment of the MitraClip Percutaneous Therapy for Heart Failure Patients with Functional Mitral Regurgitation
dFMR
Disproportionate functional mitral regurgitation
EROA
Effective regurgitant orifice area
EuroSMR
European Registry of Transcatheter Repair for Secondary Mitral Regurgitation
FMR
Functional mitral regurgitation
HF
Heart failure
IQR
Interquartile range
LBBB
Left bundle branch block
LV
Left ventricular
LVEDV
Left ventricular end-diastolic volume
LVEF
Left ventricular ejection fraction
MITRA-FR
Multicentre Study of Percutaneous Mitral Valve Repair MitraClip Device in Patients with Severe Secondary Mitral Regurgitation
MR
Mitral regurgitation
OR
Odds ratio
pFMR
Proportionate functional mitral regurgitation
RegVol
Regurgitant volume
RF
Regurgitant fraction
RVdFMR
Regurgitant volume/left ventricular end-diastolic volume ratio–derived disproportionate functional mitral regurgitation
RVpFMR
Regurgitant volume/left ventricular end-diastolic volume ratio–derived proportionate functional mitral regurgitation
TEER
Transcatheter edge-to-edge mitral valve repair
TTE
Transthoracic echocardiography

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Dr. Claeys has received honoraria and consultancy fees from Abbott Vascular. Dr. Swaans has served as a proctor and lecturer for Abbott Vascular, Boston Scientific, Philips Healthcare, and Bioventrix. Dr. Debonnaire has received speaker fees from Abbott Vascular in the context of MitraClip training. Dr. Daemen has received institutional grant and research support from AstraZeneca, Abbott Vascular, Boston Scientific, ACIST Medical, Medtronic, Pie Medical, and ReCor Medical. Dr. Van Mieghem has received research grant support from Abbott Vascular, Boston Scientific, Medtronic, Edwards Lifesciences, Daiichi Sankyo, and PulseCath.