Value of two-dimensional echocardiography in selecting patients and balloon sizes for percutaneous balloon mitral valvuloplasty

AbstractThe effect of valvular and subvalvular morphologic features and balloon size/mitral anulus size ratio on results of valvuloplasty were prospectively studied in 38 consecutive patients undergoing mitral valvuloplasty. The severity of valvular and subvalvular disease was graded echocardiographically from grade I to IV (mild to severe) for immobility, thickening, calcification of mitral leaflets and subvalvular thickening and fusion, yielding a maximal total score of 16. The diastolic mitral anulus diameter was measured in the apical four chamber view.After valvuloplasty, the mitral valve area increased from 0.9 ± 0.3 to 2.2 ± 0.5 cm2 (p < 0.001) with increasing mitral regurgitation in 12 (32 %) of the 38 patients. Multiple stepwise analysis revealed that the ratio of balloon size and annular size and the severity of subvalvular disease are two independent factors that correlated significantly with the mitral valve area after valvuloplasty (multiple r = 0.65, p < 0.0002). One of 34 patients with mild subvalvular disease of grade III or less had an unsatisfactory increase in mitral valve area to ≤1.5 cm2, whereas 3 of 4 patients with severe (grade IV) subvalvular disease had a valve area ≤ 1.5 cm2 (p < 0.002) after valvuloplasty.The increase in mitral regurgitation after valvuloplasty correlated significantly with the ratio of balloon to mitral anulus size and the severity of subvalvular disease (multiple r = 0.53, p < 0.003). The ratio of the sum of diameters from two balloons to annular size of ≥1.1 was associated with abruptly increased (70%) incidence of mitral regurgitation as compared with that (18%) for a smaller ratio (p < 0.01). An increase in mitral regurgitation was observed in all 4 patients with severe (grade IV) subvalvular disease compared with only 8 of 34 with mild (grade III or less) subvalvular disease (p < 0.05).It is concluded that 1) severe subvalvular thickening and fusion detected by two-dimensional echocardiography predict a poor result of balloon mitral valvuloplasty, and 2) to avoid a higher incidence of mitral regurgitation caused by oversized balloons, echocardiographic measurement of mitral anulus size is useful in guiding balloon size selection