Percutaneous mitral valvotomy using Inoue and double balloon technique: comparison of clinical and hemodynamic short term results in 350 cases

Late outcome of percutaneous mitral commissurotomy: Randomized comparison of Inoue versus double-balloon technique

BACKGROUND

Late prognosis after successful percutaneous mitral commissurotomy (PMC) is unclear. We compared late results of PMC using Inoue versus double-balloon techniques up to 25 years in a randomized trial.

METHODS

Between 1989 and 1995, 302 patients (77 men, 41 ± 11 years) with severe mitral stenosis were randomly assigned to undergo PMC using Inoue (n = 152; group I) or double-balloon technique (n = 150; group D). The end points were the composite events of death, mitral surgery, repeat PMC, or deterioration of New York Heart Association (NYHA) class ≥3.

RESULTS

During median follow-up of 20.7 years (maximum, 25.6), clinical events occurred in 82 (53.9%) patients in group I (37 deaths, 44 mitral surgeries, 9 repeat PMCs, 3 NYHA class ≥3) and in 79 (52.7%) patients in group D (34 deaths, 51 mitral surgeries, 5 repeat PMCs, 4 NYHA class ≥3). Event-free survival rates at 24 years were not significantly different between group I and group D (40.8% and 42.6%, respectively; hazard ratio [HR], 0.88; 95% confidence interval [CI], 0.65-1.20; P = .423). On multivariate analysis, absence of post-PMC commissural mitral regurgitation (MR) (HR, 1.84; 95% CI, 1.28-2.63; P = .001) and immediate post-PMC mitral valve area (MVA) <1.8 cm² (HR, 1.53; 95% CI, 1.04-2.25; P = .031) were independently correlated with clinical events after successful PMC.

CONCLUSIONS

The Inoue and double-balloon methods showed similar good clinical outcomes up to 25 years, and the achievement of effective commissurotomy to develop post-PMC commissural MR or immediate post-PMC MVA ≥1.8 cm² is important in optimizing the late results of PMC.

Therapeutic Utilities of Pediatric Cardiac Catheterization

In an era when less invasive techniques are favored, therapeutic cardiac catheterization constantly evolves and widens its spectrum of usage in the pediatric population. The advent of sophisticated devices and well-designed equipment has made the management of many congenital cardiac lesions more efficient and safer, while providing more comfort to the patient. Nowadays, a large variety of heart diseases are managed with transcatheter techniques, such as patent foramen ovale, atrial and ventricular septal defects, valve stenosis, patent ductus arteriosus, aortic coarctation, pulmonary artery and vein stenosis and arteriovenous malformations. Moreover, hybrid procedures and catheter ablation have opened new paths in the treatment of complex cardiac lesions and arrhythmias, respectively. In this article, the main therapeutic utilities of cardiac catheterization in children are discussed.

Percutaneous mitral valvuloplasty in patients with low cardiac output at high surgical risk

Among 1146 patients undergoing percutaneous mitral valvuloplasty for symptomatic mitral stenosis, 8 (4 men and women) were at high risk for surgery on the basis of the New York Heart Association functional class IV (n=8), severe pulmonary hypertension (n=5). All these patients aged 30+/-23.6 years had signs of right heart failure, high echocardiographic score (9.6+/-3.6) and low mitral valve area (0.50+/-0.19 cm(2)). The procedure resulted in an increase in mitral valve area (1.55+/-0.17 cm(2)) with a concomitant reduction in pulmonary artery systolic pressure (58.7+/-9.9 mm Hg) and decrease in tricuspid regurgitation. At follow-up (mean 14+/-3 months), one patient with renal failure... presented with a mitral restenosis is scheduled for mitral valve replacement, two patients with severe tricuspid regurgitation required tricuspid annuloplasty. In conclusion, percutaneous mitral valvuloplasty is feasible and safe in patients at high surgical risk and can be considered as an acceptable alternative to surgery.

Long-term clinical and echocardiographic outcome of percutaneous mitral valvuloplasty: randomized comparison of Inoue and double-balloon techniques

OBJECTIVES

The purpose of the present study was to compare the long-term clinical and echocardiographic results of the Inoue and the double-balloon techniques.

BACKGROUND

The large randomized trial comparing the extent of commissurotomy and the long-term results between the double-balloon and Inoue balloon techniques has not been reported.

METHODS

We conducted a prospective, randomized trial comparing two procedures in 302 consecutive patients who underwent percutaneous mitral valvuloplasty (PMV) using Inoue (n = 152; group I) or double-balloon technique (n = 150, group D) between 1989 and 1995. The sample size was planned to provide the study with approximately 80% power for the detection of a 10% difference between the two groups.

RESULTS

There were no significant differences in baseline characteristics between the two groups. Immediately after PMV, mitral valve area (MVA) increased from 0.9 +/- 0.2 to 1.8 +/- 0.3 cm2 in group I and from 0.9 +/- 0.2 to 1.9 +/- 0.3 cm2 in group D. No significant differences existed between the two groups in terms of development of commissural splitting, commissural mitral regurgitation (CMR), moderate to severe mitral regurgitation (MR) and MVA after PMV. The successful immediate results (MVA > or =1.5 cm2 and MR < or =2) were achieved in 127 (84%) patients of group I and 122 (81%) patients of group D (p = NS). Annual clinical and echocardiographic evaluation was completed for 290 (96%) patients with mean follow-up of 51 +/- 27 months. Adverse events occurred in 19 (13%) patients of group I (3 deaths, 7 mitral valve replacements, 5 repeat PMV, 2 NYHA class > or =3, 2 technical failures) and 16 (11%) patients of group D (2 deaths, 10 mitral valve replacements, 3 repeat PMV, 1 NYHA class > or =3). Estimated actuarial seven-year event-free survival was 75 +/- 7% in group I and 82 +/- 6% in group D (p = NS). Estimated actuarial seven-year restenosis-free survival was 67 +/- 7% in group I and 76 +/- 6% in group D (p = NS). On multivariate analysis, unsuccessful immediate result (p < 0.001) and absence of CMR (p < 0.01) were independently related with events. Absence of CMR and smaller mitral valve area after PMV were independently related with restenosis (p < 0.001).

CONCLUSIONS

The Inoue and double-balloon techniques were equally effective in commissurotomy and produced similar, excellent long-term results. The achievement of complete commissurotomy with development of CMR or larger post-PMV mitral valve area is important to optimize the long-term results of PMV.

[The evolution of severe postvalvuloplasty mitral insufficiency]

Percutaneous mitral valvuloplasty has become the technique of choice for mitral stenosis with favorable anatomic features. However, mitral regurgitation is an important complication of this technique that has not reduced with Inoue technique. This study reports the clinical and echocardiographic follow-up (28 +/- 20 months) of 20 patients who developed severe mitral regurgitation after percutaneous mitral valvuloplasty with Inoue technique. The patients were divided into two groups on the basis of the need for mitral valve replacement during follow-up. We analyzed variables before and after percutaneous mitral valvuloplasty using univariate analysis. Multivariate analysis was performed to identify variables as independent predictors of the need for mitral valve replacement. Ten patients needed mitral valve replacement during follow-up. Multivariate analysis showed that suboptimal result of percutaneous mitral valvuloplasty (MVA < 1.5 cm2) was the only independent predictor of the need of mitral valve replacement. We concluded that the need for MVR in patients who develop severe mitral regurgitation after percutaneous mitral valvuloplasty was related to suboptimal result of procedure.

Balloon mitral valvotomy in pregnancy: maternal and fetal outcomes

BACKGROUND

Rheumatic mitral valve stenosis contributes to significant morbidity in pregnancy. Surgical commissurotomy has been performed during pregnancy in patients with severe mitral stenosis for several decades, but the efficacy and safety of percutaneous balloon mitral valvotomy (BMV) in this subset has not been clearly defined.

STUDY DESIGN

In 1996 and 1997, 40 pregnant women aged 24+/-5 years underwent BMV at 21+/-11 weeks of pregnancy. Special shielding was used during BMV to limit radiation to the fetus, except in those who were to undergo medical termination of pregnancy subsequently. A detailed echocardiographic evaluation was performed before and after BMV. After the BMV, the 29 patients in whom pregnancy was continued were assessed every 2 weeks for symptoms and fetal growth.

RESULTS

The BMV procedure was successful in 39 patients with an increase in mitral valve area from 0.8+/-0.2 cm2 to 1.7+/-0.2 cm2 (p < 0.001) and marked symptomatic relief. Fluoroscopy time was 7.8+/-1.9 minutes. Eleven patients whose BMV was performed before 20 weeks of pregnancy, subsequently underwent medical termination of pregnancy uneventfully. Eighteen patients had a normal delivery, three underwent cesarean section for fetal distress, one had a preterm delivery, and there was one stillbirth. Four patients are continuing pregnancy and two are lost to followup. Fullterm delivery data were available in 23 babies, whose birth weights were 2.32+/-0.5 kg. None of these babies needed any special care and were healthy at discharge.

CONCLUSIONS

During pregnancy, BMV by the Inoue technique is feasible, safe, and effective. There is marked symptomatic relief, along with excellent maternal and fetal outcomes.

Emergent balloon mitral valvotomy in patients presenting with cardiac arrest, cardiogenic shock or refractory pulmonary edema

OBJECTIVES

The present study was performed to determine the outcome of emergent balloon mitral valvotomy (BMV) in patients with cardiac arrest, pulmonary edema or cardiogenic shock.

BACKGROUND

In India, many patients with mitral stenosis present in critical condition. They have high mortality despite surgical relief. The role of BMV in such patients is ill-defined.

METHODS

Of 558 patients undergoing BMV between January 1993 and December 1994, 40 presented with cardiogenic shock, cardiac arrest or pulmonary edema refractory to medical treatment and underwent emergent BMV (group I). Elective BMV was performed in the remaining 518 patients (group II).

RESULTS

Age ([mean +/- SD] 40 +/- 13 vs. 31 +/- 9 years, p < 0.05), incidence of atrial fibrillation (35% vs. 11%, p < 0.05), pulmonary artery systolic pressure (PAsP) (64 +/- 14 vs. 51 +/- 12 mm Hg, p < 0.001) and mitral valve (MV) score (7.4 +/- 1.2 vs. 6.4 +/- 1, p < 0.001) were higher and MV area lower (0.74 +/- 0.17 vs. 0.86 +/- 0.14 cm2, p < 0.001) in group I patients. After emergent BMV in group I, mitral regurgitation occurred in 15%, and the mortality rate was 35%. Stepwise logistic regression analysis identified MV score > or =8 (p = 0.008), PAsP > or =65 mm Hg (p = 0.023) and cardiac output < or =3.151 liters/min (p = 0.001) as significant predictors of a fatal outcome. Follow-up of 1 to 16 months (median 8) was available in 20 of 26 survivors in group I, of whom 15 were asymptomatic. The gain in MV area and the decrease in transmitral gradient and PAsP obtained immediately after BMV persisted during the follow-up period.

CONCLUSIONS

Emergent BMV is feasible in critically ill patients. In-hospital survivors have excellent clinical and hemodynamic status at intermediate follow-up.

[Long-term results of percutaneous mitral valvuloplasty]

OBJECTIVES

The aim of this study was to assess the long-term results of percutaneous transvenous mitral commisurotomy in our institution, and to evaluate potential predictors of long-term event-free survival.

PATIENTS AND METHODS

Between 1990 and 1996, 204 patients underwent percutaneous transvenous mitral commisurotomy with an Inoue balloon. One hundred and thirty two patients were followed for up to 9 months. Mean time of follow-up was 2.6-1.5 years (7 days-5.7 years). End points were considered mitral surgery, death and functional class III-IV. Long-term event-free survival analysis was performed to determine independent predictors of event-free survival.

RESULTS

At the end of the study, 88% of patients were classified as New York Heart Association class I-II. Multivariate analysis revealed that independent predictors of major events were stiffness and thickening of the valve, presence of severe left atrial enlargement as factors pre-procedure; with suboptimal results and significant mitral regurgitation after percutaneous transvenous mitral commisurotomy.

CONCLUSIONS

Percutaneous transvenous mitral commisurotomy with Inoue balloon is a safe and effective technique. Good results are maintained at long-term follow-up and the best results are obtained in patients with flexible and thin valves, with mild or moderate enlargement of left auricle and in cases with optimal results and without severe mitral regurgitation as a complication of the procedure.

Percutaneous transvenous mitral commissurotomy using Inoue balloon in children less than 12 years

Rheumatic mitral stenosis in some parts of the world afflicts even young children. Percutaneous transvenous mitral commissurotomy (PTMC) using Inoue balloon in these children is not well reported. Forty-five children (aged 7-12 years, mean 11.0 +/- 1.2 years) with severe rheumatic mitral stenosis (mitral valve area [MVA] 0.64 +/- 0.14 cm2) underwent PTMC. The pulmonary artery wedge pressure (PAW) decreased from 24.3 +/- 8.6 to 14.7 +/- 7.2 mmHg (P < 0.0001) and mean diastolic gradient decreased from 24.3 +/- 7.7 to 7.9 +/- 5.9 mmHg with the final MVA of 1.63 +/- 0.45 cm2 (P < 0.0001). Complications included significant mitral regurgitation (MR) in three children and atrial shunting in two patients. No procedural death, systemic embolism, and cardiac tamponade were encountered. Twenty-four children had maximum balloon size (MBS) same as recommended balloon size (RBS) derived according to the height (group I) and 21 children had MBS 1-3 mm less than RBS (group II). Despite the lesser maximum balloon size, the final results were comparable in both groups (MVA group 1.66 +/- 0.44 vs. group II 1.61 +/- 0.48 P = NS). The incidence of significant MR (2 and 1 in group I and group II, respectively) was similar. On follow-up of 20.4 +/- 16.3 months (range 3-56 months), one child developed restenosis. We conclude that PTMC is safe and effective in children less than 12 years of age. However, the smaller balloon size than the RBS derived from height may be equally effective and possibly safer.

Comparison of late outcome between Inoue balloon and double-balloon techniques for percutaneous mitral valvotomy in a matched study

The follow-up results between Inoue balloon (n = 43, group 1) and double-balloon (n = 43, group 2) mitral valvotomies were compared in a patient-to-patient matched study. Matching was based on patients' age, mitral valve echo score, fluoroscopic calcification, mitral valve area before valvotomy, and follow-up period. The mean follow-up period was 13 +/- 9 months for both groups. At follow-up, 72% of patients were symptom free in each group; 2 (4.7%) patients in group 1 and 1 (2.3%) patient in group 2 underwent mitral valve replacement surgery. Of these 3 patients, 2 died after surgery, 1 from each group. The mitral valve area by Doppler was 1.8 +/- 0.3 cm2 in group 1 and 1.8 +/- 0.4 cm2 in group 2 (p = 0.7); the area by echo planimetry was 1.7 +/- 0.3 cm2 in group 1 and 1.8 +/- 0.3 cm2 in group 2 (p = 0.3) at follow-up. Restenosis occurred in 5 (12%) patients from each group. The cumulative restenosis-free rate was 96% at 1 years, 78% at 2 years, and 58% at 3 years in group 1 and 98%, 76%, and 51%, respectively, in group 2 (p = 0.8). Balloon selection did not appear to influence the clinical outcome at follow-up. We conclude that both the inoue balloon and the double-balloon valvotomies are effective therapies with comparable follow-up results for patients with mitral stenosis.

Balloon impasse: a marker for severe mitral subvalvular disease and a predictor of mitral regurgitation in Inoue-balloon percutaneous transvenous mitral commissurotomy

In certain instances of percutaneous transvenous mitral commissurotomy, the Inoue catheter balloon, although deflated and properly aligned, becomes held up or checked at the mitral valve. This "balloon impasse," observed in 13 of 760 patients undergoing the commissurotomy, reflects severe obstructive subvalvular disease even though echocardiographic evidence suggests otherwise. Our experience shows that the sign portends severe mitral regurgitation if the usual balloon sizing method is used. Such a situation occurred with four of the first six patients. In the next seven patients, the use of smaller balloon catheters (PTMC-18 or PTMC-20) for the initial set of stepwise dilatations averted creation of severe mitral regurgitation. When the "balloon impasse" sign is encountered during the commissurotomy procedure, the catheter selection and balloon sizing method should be judiciously altered.

Percutaneous balloon mitral valvuloplasty by the Inoue technique: a multicenter study of 4832 patients in China

Between November 1985 and January 1994, 4832 patients with rheumatic mitral stenosis from 120 medical centers in China underwent PBMV by the Inoue technic. There were 1440 men and 3392 women with a mean age of 36.8 +/- 12.3 years. The procedure success rate was 99.30%. Major complications included death in 0.12%, > or = 3+/4+ mitral regurgitation in 1.41%, cardiac tamponade in 0.81%, and thromboembolism in 0.48%. After PBMV, the mean left atrial pressure decreased from 26.2 +/- 7.6 mm Hg to 11.4 +/- 6.1 mm Hg (p < 0.001); mean mitral diastolic gradient decreased from 18.3 +/- 5.1 mm Hg to 5.4 +/- 3.1 mm Hg (p < 0.001); pulmonary artery systolic pressure decreased from 51.2 +/- 14.8 mm Hg to 33.9 +/- 8.8 mm Hg (p < 0.001); cardiac output increased from 3.8 +/- 1.3 L/min to 4.8 +/- 1.2 L/min (p < 0.001); and mitral valve area expanded from 1.1 +/- 0.3 cm2 to 2.1 +/- 0.2 cm2 (p < 0.001). Functional status was NYHA class IV in 5.6%, class III in 38.8%, class II in 55.5%, and class I in 0.1% of patients before PBMV and improved to class I in 75.8%, class II in 23%, and class III in 1.2% after PBMV. The rate of restenosis was 5.2% over a follow-up period of 32.2 +/- 14.2 months in the entire group and 4.6% over a follow-up period of 5.1 +/- 1.0 years in Guangdong Cardiovascular Institute, where PBMV was begun in China.(ABSTRACT TRUNCATED AT 250 WORDS)

Controversies in balloon mitral valvuloplasty: the when (timing for intervention), what (choice of valve), and how (selection of technique)

Despite the established role of percutaneous balloon mitral valvuloplasty (BMV) in the treatment of mitral stenosis, major controversial issues in the realm of BMV persist. With increased operator experience, BMV has now been extended to include various controversial scenarios, such as mild mitral stenosis, adverse valve morphologies, and high-risk patients with concomitant anatomic distortions which are technically demanding. In skilled hands, however, BMV has yielded a favorable outcome in these settings. Furthermore, the debate on whether the Inoue or the double-balloon approach is superior continues. Studies to date have shown equal efficacy of the two BMV methods in terms of valve enlargement although the Inoue approach is clearly simpler to execute and may potentially be associated with a lower risk of creating severe mitral regurgitation. Last, because of the lack of consensus on optimal balloon sizing for BMV, perhaps the best method to adopt at this stage is one that is simple and safe to apply across a broad spectrum of valve anatomy.

Inoue balloon mitral valvotomy in patients with severe valvular and subvalvular deformity

OBJECTIVES

This study evaluated the immediate and long-term results of percutaneous Inoue balloon mitral valvotomy in patients with severe valvular and subvalvular deformity.

METHODS

We reviewed the prevalvotomy transthoracic echocardiograms of patients from the North American multicenter Inoue registry with total Massachusetts General Hospital (MGH) echocardiographic scores > or = 10. The echocardiograms were rescored by two investigators to assess valvular and subvalvular morphology to eliminate interinstitutional variability. Ninety patients were originally assigned scores > or = 10. After rescoring, 18 patients (20%) were eliminated, leaving 72 study patients.

RESULTS

Balloon mitral valvotomy was technically successful in 69 (96%) of the 72 patients. Mean (+/- SD) mitral valve area increased from 0.9 +/- 0.3 to 1.5 +/- 0.5 cm2. An immediate optimal result, defined as > or = 50% increase in mitral valve area or a final area > or = 1.5 cm2 with no major complications, was achieved in 46 patients (64%). End points for clinical follow-up (events) included mitral valve replacement, repeat valvotomy or death. At a mean follow-up of 22.9 +/- 11.0 months, 22 patients (31%) required mitral valve replacement or a second valvotomy, 9 patients (13%) died, and 32 patients (45%) were in New York Heart Association functional class I or II. Univariate predictors of an immediate optimal result included sinus rhythm, male gender and a lower University of Southern California commissural calcium score. Only sinus rhythm predicted an optimal result by multivariate analysis. Actuarial 3-year event-free survival was 42%. Univariate predictors of event-free survival were a lower grade of mitral regurgitation, lower MGH total echocardiographic score, lower MGH leaflet thickness subscore and lower prevalvotomy left ventricular systolic pressure. Only grade of mitral regurgitation after valvotomy predicted event-free survival by multivariate analysis.

CONCLUSIONS

Inoue mitral valvotomy in patients with severe valvular and subvalvular deformity has a high technical success rate and good immediate hemodynamic result but a high cardiovascular event rate in follow-up. Mitral valve replacement should be considered in surgical candidates with an MGH total echocardiographic score > or = 10 because it may be able to provide better long-term event-free survival. Balloon valvotomy remains a reasonable palliative therapeutic option for some patients with severe valvular deformity and high surgical risk.

Retrograde nontransseptal balloon mitral valvuloplasty for rheumatic mitral stenosis

Retrograde nontransseptal balloon mitral valvuloplasty is a relatively new technique for dilating stenosed mitral valves, wherein a specially designed steerable catheter is used to enter the left atrium retrogradely. Over a 1-yr period, 52 patients (34 M, 18 F; mean age 26.4 +/- 6.5 yr) with symptomatic noncalcific rheumatic mitral stenosis underwent balloon mitral valvuloplasty by this technique at our center. The procedure was completed in 51 out of the 52 patients and technically successful dilatation was achieved in 47 (90.4%) patients. The mean valve area increased from 0.8 +/- 0.2 cm2 to 1.86 +/- 0.37 cm2 and end diastolic gradients decreased from 21.2 +/- 9.4 mm Hg to 4.0 +/- 2.2 mm Hg. Significant mitral regurgitation (> 2+) developed in two (3.9%) patients, and both remained stable on medical treatment. In two patients, there was a significant decrease in femoral pulse, which improved with thrombolytic therapy. Our study is the first report of this technique from a center other than that of its origin. The results of this study further establish that this new retrograde technique may be a useful alternative to the conventional transseptal techniques for mitral valvuloplasty.

Percutaneous balloon valvuloplasty compared with open surgical commissurotomy for mitral stenosis

BACKGROUND

Percutaneous balloon mitral valvuloplasty has been proposed as an alternative to open surgical commissurotomy for the treatment of rheumatic mitral-valve stenosis.

METHODS

We enrolled 60 patients with severe mitral stenosis and favorable valvular anatomy in a prospective, randomized trial comparing the two procedures. All patients underwent cardiac catheterization before the procedure and one week, six months, and three years thereafter. Hemodynamic data were analyzed by investigators who were blinded to the patients' treatment assignments.

RESULTS

Mitral-valve areas improved initially in both groups, from a mean (+/- SD) of 0.9 +/- 0.3 cm2 to 2.1 +/- 0.6 cm2 in the balloon-valvuloplasty group (30 patients; P < 0.01) and from 0.9 +/- 0.3 cm2 to 2.0 +/- 0.6 cm2 in the surgical group (30 patients; P < 0.001). Although improvement was maintained in both groups, mitral-valve areas were greater in the patients in the balloon-valvuloplasty group at three years (2.4 +/- 0.6 cm2, vs. 1.8 +/- 0.4 cm2 in the surgery group, P < 0.001). Restenosis occurred in three patients in the balloon-valvuloplasty group and four in the surgery group. One patient in the balloon-valvuloplasty group died of an apparent stroke after 2.5 years; four patients in the balloon-valvuloplasty group had residual atrial septal defects, and three patients (two in the balloon-valvuloplasty group and one in the surgery group) were judged to have severe mitral regurgitation. Seventy-two percent of the patients who underwent balloon valvuloplasty and 57 percent of the surgically treated patients were in New York Heart Association functional class I (i.e., they had no cardiovascular symptoms) at three years. No patient was lost to follow-up.

CONCLUSIONS

In the treatment of mitral stenosis, balloon valvuloplasty and open surgical commissurotomy have comparable initial results and low rates of restenosis, and both produce good functional capacity for at least three years. The potential complications associated with balloon valvuloplasty should be noted. The better hemodynamic results at three years, lower cost, and elimination of the need for thoracotomy suggest that balloon valvuloplasty should be considered for all patients with favorable mitral-valve anatomy.

A simple balloon-sizing method in Inoue-balloon percutaneous transvenous mitral commissurotomy

This study was carried out to examine whether the previously determined balloon sizing method based on patient height was valid for percutaneous transvenous mitral commissurotomy using the current second-generation Inoue balloon catheter. The study consisted of 70 patients with pliable noncalcified mitral valves (group 1) and 85 patients with calcified mitral valves and/or severe subvalvular lesions (group 2). The mitral valve area was increased more in group 1 than in group 2 (1.0 +/- 0.3 to 1.9 +/- 0.5 cm2 versus 1.0 +/- 0.3 to 1.6 +/- 0.5 cm2, P = 0.002). Using the stepwise dilatation technique, none of the group 1 patients developed severe mitral regurgitation. Severe mitral regurgitation occurred in 4 patients (4.7%) in group 2. In conclusion, a simple balloon sizing method based on body height for selection of an appropriate-sized balloon catheter, as well as an initial inflated balloon diameter for the stepwise dilatation technique is useful for optimal acute outcomes in mitral commissurotomy.