Balloon-Expandable Transcatheter Mitral Valve Implantation Outcomes

Study Questions:

What are the clinical and hemodynamic outcomes following balloon-expandable transcatheter mitral valve implantation (TMVI; implanted as valve-in-valve, valve-in-ring, and valve-in-calcified annulus)?

Methods:

In a single-center experience, all patients undergoing TMVI from July 2010 to July 2017 were prospectively included. The indications for TMVI relied on the judgment of a local heart valve team. Patients were followed at 1 month, 1 year, and yearly thereafter.

Results:

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)%. The indications for TMVI were bioprosthesis failure (valve-in-valve) in 37.3%, annuloplasty failure (valve-in-ring) in 33.0%, and severe mitral annular calcification (MAC) in 29.7%. A 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 hemodynamically 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, a major stroke occurred in 2.2% of patients, and 8.8% of patients had valve thrombosis. 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 among patients in whom TMVI was seated in severe 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 mm Hg at baseline to 6.0 ± 2.3 mm Hg at discharge (p < 0.001), without changes at 6-month to 1-year follow-up.

Conclusions:

The authors concluded that TMVI using balloon-expandable valves in selected patients with bioprosthesis failure, annuloplasty failure, or severe MAC was associated with a low rate of periprocedural complications and acceptable long-term outcomes.

Perspective:

Data from this relatively large single-center experience of TMVI among patients with prior bioprosthetic mitral valve replacement, prior mitral valve annuloplasty, or severe MAC (predominantly performed using a transseptal approach) suggests that valve implantation is feasible in most (approximately 85%), and that approximately 10% of patients had died (7.7%) or had a stroke (2.2%) within 30 days; all-cause mortality was 21% at 1 year and 36% at 2 years. Higher mortality (12 deaths among 27 patients during the follow-up period) among patients with severe MAC (rather than prior MV replacement or repair) was an independent predictor of mortality, suggesting that the procedure may be less well suited to that subgroup.

Clinical Topics: Cardiac Surgery, Invasive Cardiovascular Angiography and Intervention, Valvular Heart Disease, Cardiac Surgery and VHD, Interventions and Structural Heart Disease, Mitral Regurgitation

Keywords: Bioprosthesis, Cardiac Surgical Procedures, Cardiac Valve Annuloplasty, Heart Valve Diseases, Heart Valve Prosthesis, Hemodynamics, Mitral Valve Annuloplasty, Mitral Valve Insufficiency, Outcome Assessment (Health Care), Stroke, Thrombosis


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