Hyperacute Effects of Mitral Transcatheter Edge-to-Edge Repair on Left Ventricular Volumes and Functions

Transcatheter edge-to-edge repair (TEER) is an effective intervention for high-risk patients with severe symptomatic mitral regurgitation (MR); however, its acute impact on left ventricular (LV) function has not been well-studied using advanced echocardiographic techniques. This study investigated the immediate effects of TEER on LV volumes and functions and their influence on midterm outcomes, using high-resolution 3-dimensional transesophageal echocardiography. In 80 patients who underwent TEER for severe MR (mean age 79 ± 8 years, 49% with primary MR), LV end-diastolic volume and stroke volume significantly decreased (161 ± 61 to 147 ± 54 ml and 69 ± 18 to 50 ± 15 ml, respectively), whereas end-systolic volume increased (92 ± 60 to 97 ± 45 ml, p <0.0001 for all). Left ventricular ejection fraction (LVEF) (48 ± 16% to 38 ± 14%), global longitudinal strain (16.2 ± 6.8% to 12.8 ± 5.4%), and global circumferential strain (25 ± 10.5% to 18.7 ± 8.5%) deteriorated significantly (p <0.0001 for all). Absolute reductions in LVEF and global circumferential strain were associated with baseline values and afterload reduction, indicated by 3-dimensional vena contracta area decrease (r = 0.47 and r = 0.65, p <0.0001), whereas global longitudinal strain reduction was linked to baseline values and inversely proportional to LV end-diastolic volume (r = 0.63, p <0.0001). Relative LVEF reduction emerged as the strongest predictor of mortality, with a hazard ratio of 1.76 (1.12 to 2.76) per 10% decrease. In conclusion, the acute decrease in LV function after TEER correlates with the degree of MR reduction, with greater impacts observed in circumferential function and patients with higher baseline LVEF. Relative LVEF reduction is a critical echocardiographic predictor of mortality.