Percutaneous Transseptal Bioprosthetic Implantation In Failed Prosthetic Surgical Mitral Valve - Brazilian Multicenter Experience

Background: Percutaneous intervention in patients with bioprosthetic mitral valve dysfunction is an alternative to conventional surgical treatment. Objectives: To report the first Brazilian experience with transseptal transcatheter bioprosthetic mitral valve-in-valve implantation (transseptal-TMVIV).Methods: Patients with surgical bioprosthetic dysfunction submitted to transseptal-TMVIV in 12 Brazilian hospitals were included. The significance level adopted was p<0.05.Results: From June/2016 to February/2019, 17 patients underwent transseptal-TMVIV. Their median age was 77 years (IQR,70-82) and median Society of Thoracic Surgeons predicted risk of mortality (STS-PROM) score was 8.7% (IQR,7.2-17.8). All patients had limiting symptoms of heart failure (FC >= III) and 5 (29.4%) had undergone more than one previous thoracotomy. Transseptal-TMVIV was successful in all patients. Echocardiographic assessment showed a significant reduction in mean mitral valve gradient (pre-intervention, 12 +/- 3.8 mmHg; post-intervention, 5.3 +/- 2.6 mmHg; p<0.001), in addition to an increase in mitral valve area (pre-intervention, 1.06 +/- 0.59 cm(2); post-intervention, 2.18 +/- 0.36 cm(2); p<0.001) sustained for 30 days. There was a significant and immediate reduction in the pulmonary artery systolic pressure, with an additional reduction in 30 days (pre-intervention, 68.9 +/- 16.4 mmHg; post-intervention, 57.7 +/- 16.5 mmHg; 30 days, 50.9 +/- 18.7 mmHg; p<0.001). During follow-up (median, 162 days; IQR, 102-411), significant clinical improvement (FC <= II) was observed in 87.5% of the patients. One patient (5.9%) had left ventricular outflow tract (LVOT) obstruction and died right after the procedure, and another died at 161 days of follow-up.Conclusion: The first Brazilian experience with transseptal-TMVIV shows the safety and effectivity of the new technique. The LVOT obstruction is a potentially fatal complication, reinforcing the importance of patients' selection and of procedural planning.