Transseptal versus Transapical Transcatheter Mitral Valve-in-Valve and Valve-in-Ring Implantation: A Systematic Review and Meta-Analysis.

OBJECTIVES: Transcatheter mitral valve replacement has become a useful alternative for patients with failed mitral prosthesis or annuloplasty rings who are deemed high risk for re-do surgery. We aimed to compare the clinical outcomes following transseptal (TS) and transapical (TA) approaches in transcatheter mitral valve-in-valve and valve-in-ring implantation (TMViV/R) METHODS: Electronic databases PubMed, MEDLINE, and Embase were searched through November 2022. Both clinical trials and observational studies comparing patients undergoing TS and TA TMViV/R were eligible for inclusion. Primary outcomes were 30-day and one-year mortality. Post-operative stroke, left ventricle outlet tract (LVOT) obstruction, mitral valve pressure gradient (MVPG), bleeding, and length of hospital stay were also evaluated.

RESULTS: Seven observational studies were included comparing patients undergoing TS (n=1875) and TA (n=1120) TMViV/R. The TS group had significantly lower 30-day mortality (OR: 0.66; 95% CI [0.47, 0.94]; P=0.02, I²= 0%) and lower one-year mortality risk group (HR: 0.79; 95% CI [0.63, 0.99]; P=0.04, I²= 0%) compared to the TA group. The TS group had consistent shorter in-hospital stay (MD= -3.79; 95% CI [-5.23, -2.34] days; p<0.0001, I²= 75%). Post-operative stroke, bleeding and LVOT obstruction tended to be lower in the TS but the results did not reach statistical significance. Post-operative MVPG was similar between both groups.

CONCLUSION: The TS approach has lower early mortality, lower one-year death hazard, shorter in-hospital stay, and a trend toward lower complication rates when compared to TA TMViV/R. Further controlled trials may support the evidence and provide long-term outcomes.