Left atrial remodeling in patients undergoing percutaneous mitral valve repair with the MitraClip system: an advanced echocardiography study

BACKGROUND: The goal of this study was to determine changes in left atrial (LA) function with two-dimensional speckle tracking echocardiography (2DSTE) and real-time full-volume three-dimensional echocardiography (RT3DE) after percutaneous mitral valve repair with the MitraClip system. Furthermore, we investigated whether baseline and/or changes in LA function after MitraClip repair had any impact on prognosis. METHODS: A total of 25 consecutive patients (age: 57±12 years, 76% male) with moderate-to-severe or severe mitral regurgitation (MR) were included. Patients underwent 2DSTE and RT3DE before the clip implantation and after the 12-month follow-up. Prognostic data were also recorded via the use of telephone calls and follow-up visits for 12 months after the procedure. RESULTS: Compared with the baseline, the LA reservoir strain (LA-Res) (7.66±4.3% vs 11.15±7.5%, P<.001) and LA contraction strain (LA-Pump) (4.64±4.3% vs 7.63±5.8%, P=.001) improved significantly after MitraClip repair; significant improvements were also seen in three-dimensional (3D) minimum LA volume index (LAV min) and maximum LA volume index (LAV max). On the other hand, conventional LA indices did not change. In total, eleven major adverse cardiac events (MACE) were observed at the 1-year follow-up. In univariate analyses, the preprocedural echocardiographic parameters that were associated with the MACE within 1 year after MitraClip repair were 3D-LAV min and LA-Res. Furthermore, these indices significantly correlated with improved functional parameters and MR reduction. CONCLUSION: In conclusion, a successful MitraClip procedure can reverse the process of LA remodeling within 12 months, and this can be detected by 2DSTE and RT3DE. Also, patients with preprocedural lower LA-Res and higher 3D-LAV min had the worst prognoses at the 1-year follow-up.