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.