Elevated MV Pressure Gradient After MitraClip Implant

Study Questions:

Is there a relationship between increased transvalvular gradient after a MitraClip procedure and clinical outcomes during follow-up?

Methods:

A cohort of 268 patients (75 ± 9 years of age, 68% men, weight 76 ± 15 kg, median N-terminal pro–B-type natriuretic peptide [NT-pro–BNP] 3,696 [interquartile range 1,989-7,711] pg/ml, left ventricular [LV] ejection fraction 39 ± 16%, log European System for Cardiac Operative Risk Evaluation score 20% [12%-33%]) who underwent MitraClip implantation between April 2009 and July 2014 at a single center were followed. Left atrial and LV pressure were measured during the procedure using fluid-filled catheters. The pressure gradients across the mitral valve were determined simultaneously invasively and echocardiographically immediately after MitraClip deployment. A Kaplan-Meier analysis was performed and correlated with the pressure gradients. A combined primary endpoint included all-cause mortality, LV assist device, mitral valve replacement, and redo procedure.

Results:

Kaplan-Meier analysis showed a significantly worse long-term outcome associated with invasively determined mitral valve pressure gradient >5 mm Hg at implantation for the combined endpoint (p = 0.001) and for all-cause mortality (p = 0.018); for the echocardiographically determined mitral valve gradient, a cutoff value was 4.4 mm Hg. Propensity score matching was used to balance baseline differences between the groups. In a Cox model, a residual mitral valve gradient >5 mm Hg was a significant outcome predictor in univariate and multivariate analysis (hazard ratio, 2.3; 95% confidence interval, 1.4-3.8; p = 0.00 [multivariate after adjustment for NT-pro–BNP, age, and remaining mitral regurgitation]).

Conclusions:

The authors concluded that the quality of MitraClip implantation should be analyzed, and that MitraClip repositioning should be considered if there is an elevated pressure gradient across the mitral valve.

Perspective:

Percutaneous transcatheter repair of the mitral valve with the MitraClip device might help some patients with severe mitral regurgitation at prohibitive surgical risk. This study found that an increased pressure gradient after MitraClip implantation was associated with worse outcomes in terms of all-cause mortality and a composite endpoint of all-cause mortality, LV assist device, mitral valve replacement, and redo procedure. Inasmuch as residual mitral regurgitation can be a limitation after MitraClip implantation, these data suggest that iatrogenic mitral stenosis also can be associated with worse clinical outcomes.

Clinical Topics: Anticoagulation Management, Cardiac Surgery, Heart Failure and Cardiomyopathies, Invasive Cardiovascular Angiography and Intervention, Noninvasive Imaging, Valvular Heart Disease, Cardiac Surgery and Heart Failure, Cardiac Surgery and VHD, Acute Heart Failure, Heart Failure and Cardiac Biomarkers, Mechanical Circulatory Support , Interventions and Imaging, Interventions and Structural Heart Disease, Echocardiography/Ultrasound, Mitral Regurgitation

Keywords: Cardiac Surgical Procedures, Echocardiography, Heart-Assist Devices, Heart Failure, Heart Valve Diseases, Iatrogenic Disease, Mitral Valve Insufficiency, Mitral Valve Stenosis, Natriuretic Peptide, Brain, Patient Outcome Assessment, Peptide Fragments, Risk Assessment


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