MitraClip for radiotherapy-related mitral valve regurgitation

Abstract

Objective: Owing to mediastinal and cardiac damage burden, the surgical treatment of radiotherapy-related mitral regurgitation (MR) may be associated with high operative risk or might even contraindicated. We evaluated the feasibility and outcome of MitraClip therapy in patients with radiotherapy-related MR as an alternative to surgery. Methods: Based on Doppler Echocardiography, 15 of 33 screened patients underwent MitraClip implantation. Results: Following MitraClip MR improved (residual MR ≤2+) without significant mitral valve stenosis (planimetric area 2.83 ± 0.8 cm2, mean gradient 4.6 ± 1.8 mm Hg). All patients completed a 6-month follow-up, while 14 of 15 patients achieved a longer follow-up, ranging from 12 to 72 months (median 24 months, IQR 42 months). At 6-month follow-up we observed NYHA improvement in 13 patients with an increase of 6-min walking covered distance (from 260 ± 34 to 367 ± 70, p < 0.001), sustained moderate or less MR, mild mitral stenosis in 3 patients, and significant systolic Pulmonary Artery Pressure (PAPs) reduction (from 52.5 ± 14 to 42 ± 9, p < 0.01). Sustained clinical improvement and ≤2+ MR was observed in 13 of 14 patients who completed the 12-month follow-up. Two patients died of acute pneumonia (11 months and 60 months, respectively). One patient developed moderate MV stenosis (MVA 1.4 cm2) at last follow-up (48 months) without related clinical instability. Tricuspid regurgitation improved in 12 patients with further improvement at late follow-up in 2 of 3 patient with 3+. Conclusion: MitraClip may be an effective treatment for RT-induced MR, although unexpected late stenosis may occur in the context of sustained reactive mitral apparatus damage following mediastinal radiation. Keywords: MitraClip, Radiotherapy, Mitral valve regurgitation