Methods and devices for reducing paravalvular leakage associated with a replacement mitral valve. The methods can include monitoring for paravalvular leakage between a replacement mitral valve and tissue proximate the mitral valve annulus； if a sufficient amount of paravalvular leakage is observed, deploying a tissue reshaping device at least partially within a coronary sinus； remodeling coronary sinus tissue with the tissue reshaping device to remodel at least one of mitral valve annulus tissue, at least one mitral valve leaflet, and left atrium tissue in an attempt to reduce the paravalvular leakage； and monitoring for a reduction in paravalvular leakage after the remodeling step.
