Percutaneous Mitral Balloon Valvotomy:
Six-Year Follow-up

Valvular stenosis due to rheumatic heart disease is still frequent in the country of Chile; when its course is not altered with adequate therapy, it usually carries a high morbidity and mortality rate.1–3 Rheumatic mitral stenosis primarily affects young women, invalidating them and diminishing life expectancy. The short- and long-term efficacy of surgical mitral commissurotomy has been well documented in different studies.4–6 Nevertheless, due to the inherent risks involved with cardiac surgery, the need to develop percutaneous techniques became evident almost 20 years ago. Since Inoue’s first description in 1984 of percutaneous mitral valvotomy (PMV), this procedure has become an alternative to surgery, and is currently the treatment of choice in many patients.7,8 The first PMV in Chile was performed at our institution in 1987. In this study, we report the experience accumulated since that time. Our purpose was to evaluate the intermediate- to long-term results of PMV and to analyze the clinical and echocardiographical factors that may help predict restenosis. METHODS From December 1987 to August 1999, a total of 160 PMVs were performed in patients with symptomatic mitral stenosis at our institution. The inclusion criteria were a minimum of 6 months of follow-up and an evaluation of the mitral valve with an echocardiographic score before and after the procedure. Ninety-six patients met the criteria (age, 44.6 ± 12.1 years; 86.5% female), including 39 previously reported cases.9 Median follow-up was 32.58 ± 22.45 months. Clinical information was obtained up to 72 months, either by outpatient evaluation or by telephone, in 95/96 patients (99% follow-up). Among them, 15% had 6–12 months of follow-up, 38% had 1–2 years of follow-up, 13% had 2–3 years of follow-up, 12% had 3–4 years of follow-up and 23% had > 4 years of follow-up. The clinical characteristics of the study population are summarized in Table 1. In every patient, cardiac output was assessed with the thermodilution method and mitral valve area was calculated with the Gorlin method, both before and after the procedure.10 Also, two-dimensional echocardiograms were performed 24 hours before and after the procedure to measure valvular area using planimetry and pressure half time (PHT) as described by Hatle et al.11 Since 1995, additional transesophageal echocardiograms to rule out intra-atrial thrombus have been performed in patients with atrial fibrillation. The echocardiographic score used to assess the characteristics of the mitral valve included its motility, thickness, calcification and involvement of subvalvular apparatus, as described by Wilkins et al.12 Patients with >= grade 3 mitral regurgitation using Seller’s classification13 did not undergo PMV. Mitral valve dilatation was performed using the transseptal technique. The single balloon technique described by Inoue et al.14 was performed in 89 patients using 26–30 mm balloons, while the double balloon technique described by Al Zaibag et al.15 was used in 7 patients. The result was considered optimal if mitral valve area >= 1.5 cm2 was achieved at the end of the procedure.17 The result was considered suboptimal if valve area was 8, the HR was 2.25 (95% confidence interval, 0.66–7.60). Survival free of restenosis for this group of patients was 75% at 40 months and 50% at 60 months (Figure 3). Before PMV, forty-eight patients (50%) were in NYHA Class I or II; at the end of the study, eighty-five patients (88.5%) were in this condition (p

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