What is the clinical evidence from this study?

Study design: Cohort. Population: Severe mitral valve regurgitation (n=79). Intervention: MitraClip implantation vs. Reverse remodelling. Primary outcome: All-cause mortality (OR 5.6, 95% CI 1.5-21, p=0.01).

June 7, 2018Open Access

Left ventricular remodelling patterns after MitraClip implantation in patients with severe mitral valve regurgitation: mechanistic insights and prognostic implications

Key Result

Adverse left ventricular remodelling after MitraClip implantation for severe mitral regurgitation was associated with significantly higher all-cause mortality compared to reverse remodelling (OR 5.6).

Study Design

Type

Cohort (n=79)

Multicenter

Yes

Structured PICO

Does percutaneous mitral valve repair with MitraClip improve left ventricular remodelling and all-cause mortality in patients with severe mitral regurgitation?

Population

79 patients with severe symptomatic mitral valve regurgitation (81% functional MR) deemed at high surgical risk, mean age 74 ± 10 years, 54% male. Key inclusion: underwent percutaneous mitral valve repair with MitraClip and had serial 6-month echocardiographic evaluation data available.

Intervention

Percutaneous mitral valve repair with MitraClip (average 1.4 clips used) under general anaesthesia and transoesophageal echocardiography guidance, followed by a 3-month prescription of 75 mg clopidogrel daily on top of aspirin or an anticoagulant and optimal heart failure treatment.

Outcome

Freedom from all-cause death over a follow-up period of 32 ± 16 monthshard clinical

While most patients experience reverse left ventricular remodelling after MitraClip implantation for severe MR, a small subset develops sustained adverse remodelling driven by afterload mismatch, which is strongly associated with increased mortality.

Main Result

Effect estimate: OR 5.6 (95% CI 1.5-21)

Absolute Event Rate: 67% vs 27%

p-value: p=0.01

Limitations

Exclusion of patients who died before 6 months may generate survival bias
Relatively small number of patients impedes thorough multivariate analysis
Lack of T1 mapping to assess diffuse heart fibrosis

Abstract

AIMS: The effect of MitraClip implantation on left ventricular (LV) remodelling has been shown to be highly variable. The present study wants to assess patterns of LV remodelling and its relationship with outcome. METHODS AND RESULTS: Serial echocardiography before, 1 and 6 months after MitraClip implantation was performed in 79 pts with severe mitral regurgitation (MR) (age 74 ± 10 years, New York Heart Association III/IV 80%, LV ejection fraction 38 ± 13%, logistic EuroSCORE 21 ± 15, and functional MR 81%). LV reverse/adverse remodelling was defined as a >15% decrease/>10% increase in LV end-diastolic volume (LVEDV), respectively. Patients were followed over a period of 32 ± 16 months with all-cause mortality as the primary endpoint. A sustained (6 month) reduction of MR ≤ 2 post-MitraClip implantation was observed in 83% of patients. The average decrease in LVEDV 6 months after intervention was 13% ± 16%. Reverse remodelling at 6 months occurred in 40 patients (51%), and adverse remodelling occurred in 6 patients (8%). Patients with adverse remodelling showed a 38% increase of LVEDV at 1 month vs. no early change in LVEDV in patients with reverse remodelling. During follow-up, a total of 25 patients (32%) died. Patients with adverse remodelling died more frequently than patients with reverse remodelling 67% vs. 27%, adjusted odds ratio of 5.6 (95% CI 1.5-21). CONCLUSION: The majority of patients undergoing MitraClip implantation for severe MR showed LV reverse remodelling. However, there was a small group in whom afterload mismatch resulted in sustained adverse remodelling with subsequent high mortality.

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