Exercise stress echocardiography reveals pulmonary congestion in patients with severe mitral regurgitation undergoing transcatheter edge-to-edge mitral valve repair

C. Meindl (Regensburg)¹, J. Kohler (Regensburg)¹, M. Schindler (Regensburg)¹, S. Bauer (Vöcklabruck)², F. Grewe (Regensburg)¹, M. Haus (Regensburg)¹, P. Felfeli (Regensburg)¹, M. Wester (Regensburg)¹, C. Schach (Regensburg)¹, A. Luchner (Regensburg)³, L. S. Maier (Regensburg)¹, C. Birner (Amberg)⁴, B. Unsöld (Gießen)⁵, M. Paulus (Regensburg)¹, K. Debl (Regensburg)^1
1Universitätsklinikum Regensburg Klinik und Poliklinik für Innere Med. II, Kardiologie Regensburg, Deutschland; ²Salzkammergut Klinikum Vöcklabruck Klinik für Kardiologie und Intensivmedizin Vöcklabruck, Österreich; ³Krankenhaus Barmherzige Brüder Regensburg Klinik für Kardiologie Regensburg, Deutschland; ⁴Klinikum St. Marien Klinik für Innere Medizin I Amberg, Deutschland; ⁵Universitätsklinikum Gießen und Marburg GmbH Medizinische Klinik I - Kardiologie und Angiologie Gießen, Deutschland

Background
Lung ultrasound (LUS) is a well established tool to reveal pulmonary congestion. The appearance of B-lines detected by LUS during exercise stress echocardiography in patients with severe mitral regurgitation undergoing transcatheter edge-to-edge mitral valve repair (M-TEER) has not been studied yet.

Methods and results
We enrolled 54 patients with symptomatic moderate to severe or severe mitral regurgitation undergoing M-TEER in a prospective single-centre study. 35 patients with preserved ejection fraction and without relevant mitral regurgitation served as a control group. B-lines were assessed by   LUS  at rest, at peak exercise and post exercise stress echocardiography using the 4-site simplified scan. In order to quantify the occurence of B-lines a score from 0-3 for each site was assigned (0: absence of B-lines, 1: <5 B-lines, 2: 5-10 B-lines, 3: >10 B-lines). Patients with severe mitral regurgitation had to stop exercise stress echocardiography earlier compared to the control group (75 [50-100] W vs. 125 [100-150] W, p<0.001). Systolic pulmonary artery pressure (sPAP) was significantly higher in patients with severe mitral regurgitation at rest (35 ± 13 mmHg vs. 24 ± 4 mmHg, p<0.001) as well as at peak exercise (56 ± 16 mmHg vs. 45 ± 9 mmHg, p<0.001). B-Lines score increased from rest to peak exercise in both groups (p<0.001 in patients, p=0.021 in controls). Patients with severe mitral regurgitation had higher B-lines score values at rest (2.0 ± 2.3 vs. 0.1 ± 0.5, p<0.001) as well as at peak exercise (5.6 ± 4.0 vs. 0.4 ± 1.0, p<0.001) than the control group.

Conclusion
Exercise stress echocardiography detects pulmonary congestion in patients with severe mitral regurgitation. This finding could be a useful tool in order to determine the indication and timing of M-TEER.