NPPB and Mitral regurgitation: Two or three studieswere included in estimating the LVESV, mitral regurgitation area, tricuspidregurgitation area, RATD, RVTD, and serum BNP concentrations after HTEBtreatment, and further subgroup analysis and meta-regression were unavailable dueto limitations in computational efficiency, as well as in the number of reports.HTEB treatment increased LVEF with moderate heterogeneity (n = 16; I2 = 62.2%) among these selected studies.