Retrograde benefit following mitral transcatheter edge-to-edge repair: medium- and long-term results from a single centre.

Aims: In patients with significant mitral regurgitation (MR), heart-lung interaction is decisive in defining symptoms and signs of heart failure. Little is known about the direct effects of mitral transcatheter edge-to-edge repair (m-TEER) on pulmonary circulation and changes in lung congestion and function. This study directly evaluates, through the execution of pulmonary function tests, the mid- and long-term impact of m-TEER on lungs.

Methods: Consecutive patients undergoing m-TEER from June 2019 to September 2023 were evaluated at baseline and at 3- and 12-month follow-up. Clinical, laboratory and echocardiographic examinations, quality-of-life questionnaire and walking test were performed, followed by spirometry and diffusing capacity of the lungs for carbon monoxide (DLCO).

Results: Sixty-eight patients (78±6 years, NYHA class III-IV) underwent effective m-TEER. At follow-up they presented improvement in echocardiographic parameters, functional data and quality of life. After TEER, DLCO significantly increased (from 67% ± 17 at baseline to 75% ± 17 and 74% ± 18 at 3- and 12-month respectively, P < 0.001) as well as spirometric indices of forced vital capacity (FVC) (from 84% ± 19 to 96% ± 20 and 91% ± 23, P < 0.001) and forced expiratory volume in the first second (FEV1) (from 90% ± 24 to 99% ± 27 and 97% ± 28, P < 0.001). At 12 months, DLCO was associated with systolic pulmonary artery pressure and right ventricular-to-pulmonary artery coupling, with spirometric measure of FVC with the 6-min walk distance.

Conclusions: This work shows the improvement of spirometric indices and DLCO on patients undergoing m-TEER. These results indicate the retrograde benefit of the procedure resulting in pulmonary decongestion due to the reduction of MR.