Selection of patients for percutaneous balloon mitral valvotomy: is there a definitive limit for the Wilkins score?

Aim: The aim of this study was to determine the early and long-term results of percutaneous balloon mitral valvotomy (PBMV) in patients with Wilkins score (WS) between 9 and 11.

Methods: We performed a retrospective review of clinical records of patients with rheumatic mitral stenosis who underwent PBMV between November 1991 and March 2008. Follow-up was obtained by telephone interview and/or clinical records. The procedure was considered unsuccessful when post-procedure mitral valve area was <1.5 cm(2).

Results: We analyzed 124 patients, 108 (87.1%) of them women. Mean age at the time of repair was 46 ± 11 years and mean follow-up time was 10 ± 4 years. Before the procedure, 100 patients (80.6%) had WS ≤ 8 and 24 (19.4%) were in the "gray zone" (>8 and <11). Patients with WS ≤ 8 and patients in the gray zone had similar ages at first intervention (45 ± 11 vs. 49 ± 11 years; p=0.095) and follow-up time (10 ± 4 vs. 11 ± 5 years; p=0.55). There were no differences between groups in gender (women: 86% vs. 92%; p=0.735), or in baseline echocardiographic measurements (mitral valve area by planimetry 1.0 cm(2) [P25-P75: 0.9-1.1] vs. 0.9 [P25-P75: 0.8-1.2], p=0.514; pulmonary artery systolic pressure 53 mmHg [P25-P75: 45-63] vs. 50 [P25-P75: 44-54], p=0.823]; left atrial diameter >55 mm [16.5% vs. 13.6%, p=1.00]; mitral regurgitation [46.5% vs. 37.5%, p=0.428]) or baseline transmitral gradient (13 mmHg [P25-P75: 10-19] vs. 13 mmHg [P25-P75: 7-20]). Improvements in mitral valve area by planimetry and in hemodynamic gradient were similar in the two groups (0.91 ± 0.39 cm(2) vs. 0.84 ± 0.44 cm(2), p=0.55; 8.8 ± 5.3 mmHg vs. 7.3 ± 5.9 mmHg, p=0.275, respectively). There were no significant differences in major complications or success rates (4.0 vs. 12.5 p=0.131; 89.9% vs. 95.8%, p=0.69) or in need for urgent surgery or future reintervention (2.0 vs. 8.3%, p=0.168; 22% vs. 27.3%, p=0.594). In-hospital mortality occurred only in patients in the WS gray zone (2 [8.3%] vs. 0%, p=0.04), one death (4.2% vs. 0%, p=0.194) possibly being related to a higher WS (secondary to stroke) and the other as a consequence of peripheral vascular complication. Improvements in NYHA functional class soon after the procedure and during follow-up were similar in the two groups. Total mortality was similar in the two groups (3.1 vs. 8.7%, p=0.244).

Conclusions: PBMV was a safe and effective procedure in patients in the WS gray zone. Optimal results can be achieved in these patients if they are carefully selected and operated at experienced centers.