Clinical and haemodynamic outcomes of balloon-expandable transcatheter mitral valve implantation: a 7-year experience.

Aims: We analysed the early and long-term clinical and haemodynamic outcomes of balloon-expandable transcatheter mitral valve implantation (TMVI) in an experienced centre.

Methods and results: All patients undergoing TMVI from July 2010 to July 2017 in our centre were prospectively included. Indication for TMVI relied on the judgement of the local heart team. Patients were followed at 1 month, 1 year, and yearly thereafter. A total of 91 patients underwent TMVI. The median age was 73 (57-81) years and 70% of patients were women. Patients were at high risk for surgery with a median EuroSCORE II of 9.6 (4.0-14.6) %. Indication for TMVI was bioprosthesis failure (valve-in-valve) in 37.3%, annuloplasty failure (valve-in-ring) in 33.0%, and severe mitral annulus calcification (MAC) in 29.7%. The transseptal approach was used in 92.3% of patients and balloon-expandable valves were used in all patients. Technical success was achieved in 84.6% of patients, one patient died during the procedure and haemodynamically significant left ventricular outflow tract obstruction occurred in three patients (3.3%). At 30 days, 7.7% of patients had died, without significant differences between groups, and a major stroke occurred in 2.2% of patients. The cumulative rates of all-cause mortality at 1-year and 2-year follow-up were 21.0% [95% confidence interval (CI) 9.9-38.8] and 35.7% (95% CI 19.2-56.5), respectively, with a higher late mortality in patients with MAC. The 2-year rates of re-intervention and valve thrombosis were 8.8% and 14.4%, respectively. At 6 months to 1 year, 68.9% of patients were in New York Heart Association Class I or II, and 90.7% of patients had mild or less mitral regurgitation. The mean transmitral gradient decreased from 9.3 ± 3.9 mmHg at baseline to 6.0 ± 2.3 mmHg at discharge (P < 0.001) without changes at 6-month to 1-year follow-up.

Conclusion: Transcatheter mitral valve implantation using balloon-expandable valves in selected patients with bioprosthesis or annuloplasty failure or severe MAC was associated with a low rate of peri-procedural complications and acceptable long-term outcomes.