Left atrial global function in chronic heart failure patients with functional mitral regurgitation after MitraClip

Background Left atrial (LA) volumes and function are believed to improve following interventional reduction of mitral regurgitation (MR) with MitraClip. However, exact LA alterations after MitraClip in patients with functional MR and functional mitral regurgitation (FMR) are unknown. Objectives We aimed to evaluate the effect of MitraClip on LA volumes and global function in patients with FMR and its importance for patients' prognosis. Methods All patients underwent three-dimensionally transthoracic echocardiography with an offline evaluation of LA geometry and strain analysis at baseline and follow-up (FU). FU examinations were planned for 6 and 12 months after MitraClip. Results We prospectively included 50 consecutive surgical high-risk (logistic EuroSCORE: 17.2 +/- 13.9%) patients (77 +/- 9 years, 22% female) with symptomatic moderate-to-severe to severe functional MR without atrial fibrillation. Echocardiographic evaluation showed that the E/E' ratio was significantly higher at FU (15.6 +/- 7.3, 24.1 +/- 13.2,p= .05) without relevant changes in systolic left ventricle (LV) function (p= .5). LA volumes (end-diastolic volume [LA-EDV] and end-systolic volume [LA-ESV]) (LA-EDV: 83.1 +/- 39.5 ml, 115.1 +/- 55.3 ml,p= .012; LA-ESV: 58.4 +/- 33.4 ml, 80.1 +/- 43.9 ml,p= .031), muscular mass (105.1 +/- 49.3 g, 145.4 +/- 70.6 g,p= .013), as well as LA stroke volume (24.6 +/- 12.5 ml, 34.9 +/- 19.1 ml,p= .016) significantly increased after the procedure. LA ejection fraction (LA-EF: 31.7 +/- 12.8%, 31.1 +/- 12.3%,p= .8) and atrial global strain (aGS: -10.8 +/- 5.4%, -9.7 +/- 4.45%,p= .4) showed no significant changes at FU. Despite no relevant changes during FU, the baseline aGS was found to be the strongest predictor for mortality and adverse interventional outcome. Conclusion MitraClip increases atrial stroke volume, atrial volumes, and muscular mass in patients with FMR. We found that the baseline aGS the strongest predictor for mortality, rehospitalization, and higher residual MR at FU.