Transcatheter mitral valve implantation: a percutaneous transapical system

Transcatheter Mitral Valve Replacement for Treating Native Mitral Valve Disease: Current Status

Transcatheter mitral valve replacement is increasingly being used as a treatment for high-risk patients who have native mitral valve disease; however, no comprehensive studies on its effectiveness have been reported. We therefore searched the literature for reports on patients with native mitral valve disease who underwent transcatheter access treatment. We found 40 reports, published from September 2013 through April 2017, that described the cases of 66 patients (mean age, 71 ± 12 yr; 30 women; 30 patients with mitral stenosis, 34 with mitral regurgitation, and 2 mixed) who underwent transcatheter mitral valve replacement. We documented their baseline clinical characteristics, comorbidities, diagnostic imaging results, procedural details, and postprocedural results. Access was transapical in 41 patients and transseptal in 25. The 30-day survival rate was 82.5%. The technical success rate (83.3% overall) was slightly but not significantly better in patients who had mitral regurgitation than in those who had mitral stenosis. Transapical access procedures resulted in fewer valve-in-valve implantations than did transseptal access procedures (P=0.026). These current results indicate that transcatheter mitral valve replacement is feasible in treating native mitral disease. The slightly higher technical success rate in patients who had mitral regurgitation suggests that a valve with a specific anchoring system is needed when treating mitral stenosis. Our findings indicate that transapical access is more reliable than transseptal access and that securely anchoring the valve is still challenging in transseptal access.

Effects of Transapical Transcatheter Mitral Valve Implantation

Purpose: In this study, transapical transcatheter mitral valve-in-valve implantation (TAMVI) was compared with surgical redo mitral valve replacement (SRMVR) in terms of clinical outcomes. Methods: We retrospectively identified patients with degenerated mitral bioprosthesis or failed annuloplasty rings who underwent redo SRMVR or TAMVI at our medical center. Clinical outcomes were based on echocardiography results. Results: We retrospectively identified patients with symptomatic mitral bioprosthetic valve dysfunction (n = 58) and failed annuloplasty rings (n = 14) who underwent redo SRMVR (n = 36) or TAMVI (n = 36). The Society of Thoracic Surgeons Predicted Risk of Mortality scores were higher in the TAMVI group (median: 9.52) than in the SRMVR group (median: 5.59) (p-value = 0.02). TAMVI patients were more severe in New York Heart Association (p-value = 0.04). The total procedure time (skin to skin) and length of stay after procedures were significantly shorter in the TAMVI group, and no significant difference in mortality was noted after adjustment for confounding factors (p-value = 0.11). The overall mean mitral valve pressure gradient was lower in the TAMVI group than in the SRMVR group at 24 months (p < 0.01). Both groups presented a decrease in the severity of mitral and tricuspid regurgitation at 3-24 months. Conclusions: In conclusion, the statistical analysis is still not robust enough to make a claim that TAMVI is an appropriate alternative. The outcome of the patient appears only to be related to the patient's pre-operative STS score. Additional multi-center, longitudinal studies are warranted to adequately assess the effect of TAMVI.