Scarce data exist on mitral valve (MV) infective endocarditis (IE) after transcatheter aortic valve implantation (TAVI). This multicenter study included a total of 579 patients with a diagnosis of definite IE after TAVI from the IE after TAVI International Registry and aimed to evaluate the incidence, characteristics, management, and outcomes of MV-IE after TAVI. A total of 86 patients (14.9%) had MV-IE. These patients were compared with 284 patients (49.1%) with involvement of the transcatheter heart valve (THV) only. Two factors were found to be associated with MV-IE: the use of self-expanding valves (adjusted odds ratio 2.49, 95% confidence interval [CI] 1.23 to 5.07, p = 0.012), and the presence of an aortic regurgitation ≥2 at discharge (adjusted odds ratio 3.33; 95% CI 1.43 to 7.73, p <0.01). There were no differences in IE timing and causative microorganisms between groups, but surgical management was significantly lower in patients with MV-IE (6.0%, vs 21.6% in patients with THV-IE, p = 0.001). All-cause mortality rates at 2-year follow-up were high and similar between patients with MV-IE (51.4%, 95% CI 39.8 to 64.1) and patients with THV-IE (51.5%, 95% CI 45.4 to 58.0) (log-rank p = 0.295). The factors independently associated with increased mortality risk in patients with MV-IE were the occurrence of heart failure (adjusted p <0.001) and septic shock (adjusted p <0.01) during the index hospitalization. One of 6 IE episodes after TAVI is localized on the MV. The implantation of a self-expanding THV and the presence of an aortic regurgitation ≥2 at discharge were associated with MV-IE. Patients with MV-IE were rarely operated on and had a poor prognosis at 2-year follow-up.
