Mitral valve apparatus : echocardiographic features predicting the outcome of percutaneous mitral balloon valvotomy
Objectives: To evaluate the significance of involvement of subvalvular apparatus in the outcome of percutaneous mitral balloon valvotomy (PMBV) in patients with mitral stenosis (MS) and to determine the predictive value of chordal length compared with current echocardiographic scores. Methods: Patients with significant MS were selected according to the Massachusetts General Hospital score (MGHS). Chordal lengths were assessed as additional markers of disease. Standard percutaneous valvotomies were performed. Valve area was assessed post-procedure with follow-up over one year. Results: Thirty-nine patients were prospectively studied. Valve area increased from a mean (SD) 0.97 (0.26) cm² to 1.52 (0.38) cm² with procedural success in 31 (79.5%) patients. There was no correlation (r = 0.09) between the MGHS and final valve area (FVA). There was a positive correlation between anterior chordal length and FVA (r = 0.66; p = 0.01). An FVA ≥ 1.5 cm² was associated with higher mean chordal lengths (p = 0.01). A positive correlation was seen between valve area pre-procedure and FVA (r = 0.61; p < 0.01). Conclusions: The MGHS is valuable in the selection of patients for PMBV, but fails to separate selected patients into prognostic groups. Assessment of chordal length provides useful additional information, predicting the outcome of PMBV more accurately. Our data may support the earlier use of PMBV (asymptomatic patients).