Predictors of long-term event-free survival and of freedom from restenosis after percutaneous balloon mitral commissurotomy

Transcatheter Therapy for Mitral Valve Stenosis

Mitral valve stenosis remains highly prevalent among the US population although with dramatically shifting demographics. The significance of rheumatic mitral disease in developing nations persists, despite improvements in preventative measures and early detection, and its presence in developed countries is still evident as observed through international migration. In addition, the substantial growth in the aging population with a heightened occurrence of concurrent cardiovascular risk factors is leading to an increased prevalence of chronic calcific degeneration and degeneration of previously repaired or replaced valves. This article aims to review various transcatheter therapies in the treatment of mitral valve stenosis.

Transcatheter Therapy for Mitral Valve Stenosis

Mitral valve stenosis remains highly prevalent among the US population although with dramatically shifting demographics. The significance of rheumatic mitral disease in developing nations persists, despite improvements in preventative measures and early detection, and its presence in developed countries is still evident as observed through international migration. In addition, the substantial growth in the aging population with a heightened occurrence of concurrent cardiovascular risk factors is leading to an increased prevalence of chronic calcific degeneration and degeneration of previously repaired or replaced valves. This article aims to review various transcatheter therapies in the treatment of mitral valve stenosis.

Closed Mitral Valvotomy Reenvision

In developing countries, like the Indian subcontinent, population overload, malnutrition, poor socio-economic status of affected groups, and health care facilities affect the treatment outcome. Nowadays procedures such as percutaneous balloon mitral valvotomy (PBMV) and open heart mitral valve replacement are offered to patients with mitral stenosis. Whenever PBMV is unavailable due to financial constraints and open surgical management cannot be offered due to overburdened healthcare facilities, closed mitral valvotomy (CMV) provides an excellent choice for patients with favorable mitral valve pathology. Many centers do not practice CMV and thus this procedure is dying out. The young generation of surgeons are not been trained in CMV. The purpose of our study is to reenvision CMV and emphasize its vital role in mitral stenosis patient subsets like pregnant women and young adults. 

We reviewed the literature for various valvotomy techniques done for mitral valve stenosis and restenosis. Immediate and late outcomes were compared between the patients receiving Percutaneous balloon mitral valvotomy and closed mitral valvotomy.

The immediate and late-term results are comparable for PBMV and CMV and no statistically significant difference exists. The post-PBMV Mitral valve area (MVA) ranged from 2.1 +/- 0.7 cm^2 to 2.3 +/-0.94 cm^2 and post CMV MVA ranged from 1.3+/-0.3 cm^2 to 2.2+/-0.85 cm^2. Complications developing in both techniques are also nearly similar. Operative mortality in CMV patients ranged from 1% to 4.2%, also observed in PBMV patients in various studies. Mitral Regurgitation occurred in both groups equally and ranged from 0.3% to 14%. Restenosis was observed in both groups in the range of 4% to 5%. High fetal loss of around 20% mortality was witnessed in pregnant mitral stenosis patients undergoing open heart surgery.

It's time to re-envision CMV since it is providing substantial outcomes and remitting the need for open-heart surgery at a very low cost in patients with mitral stenosis with a pliable valve.

Difficulties to enter the left ventricle during percutaneous transvenous mitral commissurotomy (PTMC)- our experiences of 80 cases with modified techniques

Background

Percutaneous transvenous mitral commissurotomy (PTMC) is the standard of treatment for symptomatic severe rheumatic mitral stenosis (MS). PTMC has the standard Inoue technique, but we have to modify the procedure in many technically challenging cases, especially to cross the mitral valve.

Methodology

Two over-the-wire strategies to enter the LV were taken in 80 complex cases of PTMC. The first one was done by exchanging the J-shaped wire from the balloon, introducing the spring wire into it, and pushing it into LV. The second one-removal of balloon keeping the spring wire in LA and the Mullin's sheath was introduced, and the tip of the wire was pushed into LV, and the balloon was introduced over the wire. We also changed the left atrium (LA) graphy in the RAO view instead of the AP view to facilitating entry into LV.

Results

We succeeded in 76 (95 %) cases. Strategy one was applied to all but successful in only 25 cases (31 %), and strategy 2 was applied in the remaining. Strategy 1 required less procedural time and fluoroscopic time in comparison to strategy 2 (40 ± 10 vs 60 ± 16 min, 25 ± 7 vs 35 ± 8 min). After modification of taking the LA graphy in RAO view, our rate of facing the difficulties decreased from 21 % to 9 %. Critical MS (31 %) and the giant LA (30 %) were the topmost causes of difficulties. No major complications were recorded.

Conclusion

Over-the-wire entry into LV is cost-effective, requiring no new equipment and is safe and can be used in complex cases.

Rheumatic Mitral Valve Stenosis: Diagnosis and Treatment Options

PURPOSE OF REVIEW

This review provides an update on rheumatic mitral stenosis. Acute rheumatic fever (RF), the sequela of group A β-hemolytic streptococcal infection, is the major etiology for mitral stenosis (MS).

RECENT FINDINGS

While the incidence of acute RF in the Western world had substantially declined over the past five decades, this trend is reversing due to immigration from non-industrialized countries where rheumatic heart disease (RHD) is higher. Pre-procedural evaluation for treatment of MS using a multimodality approach with 2D and 3D transthoracic and transesophageal echo, stress echo, cardiac CT scanning, and cardiac MRI as well as hemodynamic assessment by cardiac catheterization is discussed. The current methods of percutaneous mitral balloon commissurotomy (PMBC) and surgery are also discussed. New data on long-term follow-up after PMBC is also presented. For severe rheumatic MS, medical therapy is ineffective and definitive therapy entails PMBC in patients with suitable morphological mitral valve (MV) characteristics, or surgery. As procedural outcomes depend heavily on appropriate case selection, definitive imaging and interpretation are crucial. It is also important to understand the indications as well as morphological MV characteristics to identify the appropriate treatment with PMBC or surgery.

Immediate and late clinical outcomes of balloon mitral valvotomy based on immediate postballoon mitral valvotomy mitral valve area & percentage gain in mitral valve area-A tertiary centre study

AIM

The aim of the study was to compare the immediate and late clinical outcomes of balloon mitral valvotomy (BMV), based on the immediate post-BMV valve area and percentage gain in mitral valve area (MVA).

METHODS

Clinical data of 818 consecutive patients who underwent BMV in our institute from 2000 to 2008 were analyzed retrospectively. They were categorized into three groups based on the postprocedural MVA and percentage gain in valve area-(1) 50% gain with final MVA <1.5 cm², group 1 (fair result); (2) final MVA of ≥1.5 cm², group 2 (good result); and (3) <50% gain with final MVA <1.5 cm², group 3 (suboptimal result).

RESULTS

The baseline characteristics of the three patient groups were clearly distinct. Those who had <50% gain with final MVA <1.5 cm² were older and had higher incidence of atrial fibrillation (17 [22.4%]), heart failure (32 [42.1%]), pulmonary artery hypertension (45 [59.2%]), and significantly deformed valves (39 [51.3%]) at baseline. At a mean follow-up period of 5.64 ± 3.84 years, incidence of redo BMV (23 [4.6%]) and mitral valve replacement (17 [3.4%]) was higher in them than those with immediate MVA ≥1.5 cm². Among those with MVA <1.5 cm², events on follow-up were similar irrespective of the percentage gain in MVA.

CONCLUSIONS

Immediate postprocedural MVA of ≥1.5 cm², and not percentage gain, predicts better long-term clinical outcomes after BMV. Patients who had less than 50% gain with final MVA <1.5 cm² represent high-risk population with advanced mitral valve disease and comorbidities.

Management of atrial fibrillation in patients with rheumatic mitral stenosis

Atrial fibrillation (AF) is frequent in patients with rheumatic mitral stenosis (MS). Pressure overload leads to marked structural and electrical remodelling of left atrium. The frequency of persistent AF increases with age and paroxysmal, asymptomatic, AF seems even more frequent. The occurrence of AF worsens the haemodynamic tolerance of MS and markedly increases the risk of thromboembolic events. AF has a negative impact on the natural history of MS and on its outcome after commissurotomy. The respective indications of rhythm and rate control should be adapted to patient characteristics, particularly the consequences of MS, and take into account the high risk of recurrence of AF. Oral anticoagulant therapy is mandatory when AF complicates MS, regardless of its severity and CHA2DS2-VASc score. Non-vitamin K antagonists oral anticoagulants are not recommended in moderate-to-severe MS due to the lack of data. Percutaneous mitral commissurotomy does not appear to prevent the occurrence of AF in MS but should be considered as the first-line therapy when AF is associated with severe symptomatic MS, followed by the discussion of cardioversion or ablation. AF ablation should be considered in patients with mitral disease requiring intervention, but the ideal timing and techniques are difficult to determine due to the lack of appropriate specific randomised trials in patients with MS.

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.

Intermediate outcomes of rheumatic mitral stenosis post-balloon mitral valvotomy

Background

Balloon mitral valvotomy is a standard therapeutic modality for managing rheumatic mitral stenosis. Data on intermediate outcomes of this procedure are limited. Thus we investigated the intermediate outcome after balloon mitral valvotomy performed at a large tertiary center in India.

Methods

Case records and follow-up data of 2330 patients who underwent valvotomy from June 1999 to December 2005 were retrieved from the hospital information system and analyzed.

Results

The median age of the patients was 32 ± 11 years, 1363 were female including 36 who were pregnant, and 379 were in atrial fibrillation. Follow-up ranged from 1 to 14 years (mean 4.5 years, median 4.0 years). The procedural success rate was 93%. Atrial fibrillation, higher functional class, and worse valve morphology were independent predictors of a poor procedural outcome. Patients with sinus rhythm had better event-free survival (10.43 years, 95% confidence interval: 10.1–10.7) compared to those with atrial fibrillation (8.17 years, 95% confidence interval: 7.5–8.8). Patients who achieved a valve area >1.75 cm2 had a better event-free survival (11.7 years, 95% confidence interval: 11.4–12.0) than those with a valve area of 1.5–1.74 cm2 (9.3 years, 95% confidence interval: 9.0–9.7). On multivariate analysis, higher functional class, worse valve morphology, and new significant mitral regurgitation were predictors of a poor outcome. Achieved mitral valve area >1.75 cm2 was an independent predictor of a good outcome.

Conclusion

Patients with sinus rhythm, less gross valve deformity, and a post-balloon mitral valvotomy area >1.75 cm2 had better intermediate outcomes.

A review of valve surgery for rheumatic heart disease in Australia

BACKGROUND

Globally, rheumatic heart disease (RHD) remains an important cause of heart disease. In Australia it particularly affects older non-Indigenous Australians and Aboriginal Australians and/or Torres Strait Islander peoples. Factors associated with the choice of treatment for advanced RHD remain variable and poorly understood.

METHODS

The Australian and New Zealand Society of Cardiac and Thoracic Surgeons Cardiac Surgery Database was analysed. Demographics, co-morbidities, pre-operative status and valve(s) affected were collated and associations with management assessed.

RESULTS

Surgical management of 1384 RHD and 15843 non-RHD valve procedures was analysed. RHD patients were younger, more likely to be female and Indigenous Australian, to have atrial fibrillation (AF) and previous percutaneous balloon valvuloplasty (PBV). Surgery was performed on one valve in 64.5%, two valves in 30.0% and three valves in 5.5%. Factors associated with receipt of mechanical valves in RHD were AF (OR 2.69) and previous PBV (OR 1.98) and valve surgery (OR 3.12). Predictors of valve repair included being Indigenous (OR 3.84) and having fewer valves requiring surgery (OR 0.10). Overall there was a significant increase in the use of mitral bioprosthetic valves over time.

CONCLUSIONS

RHD valve surgery is more common in young, female and Indigenous patients. The use of bioprosthetic valves in RHD is increasing. Given many patients are female and younger, the choice of valve surgery and need for anticoagulation has implications for future management of RHD and related morbidity, pregnancy and lifestyle plans.

Imaging in mitral stenosis: assessment before, during and after percutaneous balloon mitral valvuloplasty

Detailed assessment of mitral valve morphology is required to select patients for successful percutaneous balloon mitral valvuloplasty (PBMV). The mitral valve is routinely imaged using transthoracic and transesophageal echocardiography, which have more recently been supplemented with magnetic resonance imaging, 3D echocardiography and intracardiac echocardiography. The scope of PBMV is expanding and it is increasingly used for patients previously considered to have unfavorable mitral morphology. Here we review the evidence to support the examination of each component of the mitral valve and its surrounding structures and the advantages of each imaging modality. Appropriate echocardiographic views are recommended and periprocedural and postprocedural imaging techniques are discussed.

Patient profile and results of percutaneous transvenous mitral commissurotomy in mitral restenosis following prior percutaneous transvenous mitral commissurotomy vs surgical commissurotomy

BACKGROUND

Patients with mitral restenosis who have undergone prior PTMC or surgical commissurotomy have increased. Predictors of outcome of repeat PTMC in either subgroup of patients may be different.

AIMS AND OBJECTIVES

Aim was to assess and compare the immediate results of PTMC in patients who had undergone a prior PTMC or surgical commissurotomy.

METHODS AND RESULTS

This is a single center, prospective, open label study. Of 70 patients in study, 44 (62.85%) patients had prior history of PTMC and 26 (37.15%) had prior surgical commissurotomy (closed/open). Average time from the initial procedure was 8.88 ± 5.36 years overall, 6.75 ± 3.38 for patients with prior PTMC and 16.73 ± 3.67 for patients with prior surgical commissurotomy. Prior PTMC group had 75% female, patients with prior surgical commissurotomy were older (44 ± 7 vs 33.57 ± 9.1 years, p = 0.001), had higher NYHA class (III/IV in100% vs 86.36%, p = 0.006.), higher atrial fibrillation (73.1% vs 25% p < 0.0001) and higher Wilkins' score (>8 in 88.46% vs 68.18%, p = 0.05). Successful PTMC was lower (65.4% vs 84.1%) in patients with prior surgical commissurotomy, though statistically not significant (p = 0.07). After PTMC, mitral valve area, PA systolic pressure, LA mean pressure and trans-mitral gradient were similar. Post procedure complications were not different in both the groups.

CONCLUSION

PTMC for mitral restenosis in patients with prior surgical valvotomy is as effective as in patients with prior PTMC despite older age, higher NYHA class, higher Wilkins score and atrial fibrillation and can be considered in all patients with restenosis irrespective of the type of past procedures done.

[Immediate results of repeat percutaneous mitral valvuloplasty]

Percutaneous mitral valvuloplasty (PMV) has emerged as the procedure of choice in treatment of mitral stenosis and has proved effectiveness in cases of mitral restenosis after surgical commissurotomy. However, this technique is costly, is not devoid of complication and success is not guaranteed. Indications of an attempted redo percutaneous mitral valvuloplasty (redo-PMV) are not well established. Hence the idea to study the immediate results of (re-PMV).

PURPOSE OF WORK

The purpose of this study is to evaluate the immediate results of the re-PMV in patients with mitral restenosis and analyze the different clinical and laboratory findings to determine predictors of success of re-PMV to better selection of candidates for a new attempt PMV.

METHODS

Retrospective study from a series of 40 procedures of re-PMV with the Inoue balloon succeeding a successful initial procedure, collected in the cardiology department of Habib Thameur hospital of Tunis between 1996 and 2011, in which we identified the data of clinical and paraclinical examinations.

RESULTS

The mean age of patients was 43 ± 11 years [23; 63]. Of the population, 87.5% were female (five men and 35 women). The average time between the two procedures was 8 ± 4 years [1; 15]. The immediate procedural success defined by a mitral valve area greater or equal to 1.5 cm(2) and a grade less than or equal to 2 mitral regurgitation was obtained in 31 patients (77.5%). A severe mitral regurgitation (MR) was observed in three patients (7.5%). A cerebrovascular stroke occurred in one patient (2.5%). No death or cardiac tamponade were noted. Class III or IV of NYHA, a pre-procedural MR, pulmonary hypertension and an overall score of Padial greater than 10 were retained as predictors of failure. More the overall score of Wilkins is high (>8), more it is predictive of failure. The two components of the Wilkins score: valvular mobility and subvalvular apparatus (SVA) and the parameter of the redesign of the SVA score of Padial considered separately are also predictive of failure. Only a left atrial area less than or equal to 25 cm(2) was linked to high risk of severe MR.

CONCLUSION

Redo percutaneous mitral valvuloplasty is a therapeutic alternative to surgery that is effective and promising interesting immediate results. Analysis of clinical and mainly echographic parameters is useful for predicting the success of the gesture, which will allow a better selection of candidates for re-PMV.

Late results of percutaneous mitral commissurotomy up to 20 years: development and validation of a risk score predicting late functional results from a series of 912 patients

BACKGROUND

Long-term follow-up after percutaneous mitral commissurotomy enables predictive factors of late results to be identified.

METHODS AND RESULTS

Late results of percutaneous mitral commissurotomy were assessed in 1024 consecutive patients. Good immediate results, defined as valve area ≥1.5 cm(2) without mitral regurgitation >2/4, were obtained in 912 patients (89%). These 912 patients were randomly split into 2 cohorts comprising 609 and 303 patients that were used to develop and validate, respectively, a scoring system predicting late functional results. The 20-year rate of good functional results (survival without cardiovascular death, mitral surgery, or repeat percutaneous mitral commissurotomy and in New York Heart Association class I or II) was 30.2 ± 2.0%. A multivariable Cox model identified 7 predictive factors of poor late functional results: higher final mean gradient (P<0.0001), interaction between age and final mitral valve area (P<0.0001) showing that the impact of valve area decreases with age, interaction between sex and valve calcification (P<0.0001) showing that the impact of valve anatomy is stronger in men, and interaction between rhythm and New York Heart Association class showing an impact of New York Heart Association class only in patients in atrial fibrillation (P<0.0001). A 13-point score enabled 3 risk groups to be defined, corresponding to predicted good functional results of 55.1%, 29.1%, and 10.5% at 20 years in the validation cohort.

CONCLUSIONS

Twenty years after percutaneous mitral commissurotomy in a population of patients with varied characteristics, 30% still had good functional results. Prediction of late functional results is multifactorial and strongly determined by age and the quality of immediate results. A simple validated scoring system is useful for estimating individual patient outcome.

Computerized acoustic cardiography correlates with echocardiography and invasive haemodynamics after percutaneous transvenous mitral commissurotomy

BACKGROUND

Rheumatic mitral stenosis severity has been assessed by the systolic time interval between the QRS onset and the first heart sound (QS1) by phonocardiography. We hypothesized that non-invasive computerized acoustic cardiography could evaluate mitral stenosis severity compared with echocardiography and invasive haemodynamics in patients undergoing percutaneous transvenous mitral commissurotomy (PTMC).

METHODS

27 patients underwent computerized acoustic cardiography, echocardiography, and invasive haemodynamic measurements prior to and after PTMC.

RESULTS

The mean age was 31 ± 10 years, and 21 (78%) were female. By echocardiography, mitral valve area increased from 0.82 ± 0.14 to 1.50 ± 0.24 cm(2) (p < 0.0001). The QS1 interval decreased from 101.7 ± 12.9 to 93.2 ± 9.2 ms (p < 0.0001). The change in the QS1 interval correlated with the change in mitral valve area by echocardiography (p = 0.037), right ventricular systolic pressure (p < 0.0001), and the invasive mitral valve gradient (p = 0.076).

CONCLUSIONS

Acoustic cardiography may be used as an adjunctive non-invasive diagnostic tool to assess mitral stenosis severity.

Mitral balloon valvuloplasty

Percutaneous mitral balloon valvuloplasty (MBV) was introduced in 1984 by Inoue who developed the procedure as a logical extension of surgical closed commissurotomy. Since then, MBV has emerged as the treatment of choice for severe pliable rheumatic mitral stenosis (MS). With increasing experience and better selection of patient, the immediate results of the procedure have improved and the rate of complications declined. When the reported complications of MBV are viewed in aggregate, complications occur at approximately the following rates: mortality (0-0.5%), cerebral accident (1-2%), mitral regurgitation (MR) requiring surgery (1.6-3%). These complication rates compare favorably to those reported after surgical commissurotomy. Several randomized trials reported similar hemodynamic results with MBV and surgical commissurotomy. Restenosis after MBV ranges from 4% to 70% depending on the patient selection, valve morphology, and duration of follow-up. Restenosis was encountered in 31% of the author's series at mean follow-up 9 ± 5.2 years (range 1.5-19 years) and the 10, 15, and 19 years restenosis-free survival rates were (78 ± 2%) (52 ± 3%) and (26 ± 4%), respectively, and were significantly higher for patients with favorable mitral morphology (MES ⩽ 8) at 88 ± 2%, 67 ± 4% and 40 ± 6%), respectively (P < 0.0001). The 10, 15, and 19 years event-free survival rates were (88 ± 2%, 60 ± 4% and 28 ± 7%, respectively, and were significantly higher for patients with favorable mitral morphology (92 ± 2%, 70 ± 4% and 42 ± 7%, respectively (P < 0.0001). The effect of MBV on severe pulmonary hypertension, concomitant severe tricuspid regurgitation, left ventricular function, left atrial size, and atrial fibrillation are addressed in this review. In addition, the application of MBV in specific clinical situations such as in children, during pregnancy and for restenosis is discussed.

Long-Term Results up to 19 Years of Mitral Balloon Valvuloplasty

Clinical and echocardiographic data of 547 consecutive patients (mean age, 31.5 years) undergoing mitral balloon valvuloplasty with follow-up of 1.5–19 years, were analyzed. Immediately after valvuloplasty, mitral valve area increased significantly from 0.92 ± 0.17 to 1.95 ± 0.29 cm2. Restenosis occurred in 169 (31%) patients; it was less common (20%) in those with a mitral echocardiographic score ≤8. Actuarial freedom from restenosis at 10, 15, and 19 years was 78% ± 2%, 52% ± 3%, and 26 ± 4%, respectively, and significantly higher in patients with echocardiographic scores ≤8: 88% ± 2%, 67% ± 4%, and 40% ± 6%, respectively. Event-free survival at 10, 15, and 19 years was 88% ± 2%, 60% ± 4%, and 28% ± 7%, respectively, and significantly higher in patients with echocardiographic scores ≤8: 92% ± 1%, 70% ± 4%, and 42% ± 7%, respectively. Multivariate analysis identified echocardiographic score ≤8 and post-procedure valve area ≤1.8 as predictors of restenosis, and echocardiographic score > 8 and preexisting atrial fibrillation as predictors of combined events. Valvuloplasty provides excellent results in selected patients with mitral stenosis. The long-term outcome can be predicted from the baseline characteristics of the mitral valve.

Mitral stenosis

Mitral stenosis is a common disease that causes substantial morbidity worldwide. The disease is most prevalent in developing countries, but is increasingly being identified in an atypical form in developed countries. All treatments that increase valve area improve morbidity. Mortality improves with surgery; the benefit of percutaneous balloon valvuloplasty to mortality might be similar to that of surgery but needs further study. Percutaneous balloon valvuloplasty is the treatment of choice for patients in whom treatment is indicated, except for those with suboptimum valve morphology, and even these patients are sometimes treated with this procedure if surgery is not feasible or if surgical risk is prohibitive. We review the pathology, diagnosis, and treatment options for patients with mitral stenosis.

Restenosis and adverse clinical events after successful percutaneous mitral valvuloplasty: immediate post-procedural mitral valve area as an important prognosticator

AIMS

We sought to investigate the factors associated with restenosis and its potential association with late clinical deterioration after successful percutaneous mitral valvuloplasty (PMV).

METHODS AND RESULTS

We analysed echocardiographic (median 74 months) and clinical (median 109 months) follow-up data of 329 patients who achieved procedural success, defined as mitral valve area (MVA) > or =1.5 cm(2) and mitral regurgitation (MR) < or =2/4, between 1995 and 2000. Clinical events included cardiovascular death, mitral valve surgery, and repeat PMV. The 1, 3, 5, 7, and 9 year rates of restenosis-free survival were 99 +/- 1%, 97 +/- 1%, 95 +/- 1%, 86 +/- 3%, and 72 +/- 4%, respectively. The 1, 3, 5, 7, and 9 year rates of event-free survival were 99.7 +/- 0.3%, 96.4 +/- 1.0%, 94.5 +/- 1.3%, 90.8 +/- 1.6%, and 90.0 +/- 1.7%, respectively. Immediate post-PMV MVA and commissural MR or splitting, indicators of procedural adequacy, were independent predictors of both restenosis and clinical events. The best immediate post-PMV MVA cut-off value for predicting both restenosis and clinical events within 5 years after successful PMV were 1.8 cm(2) [95% confidence interval (CI) = 1.7-1.9] and 1.9 cm(2) (95% CI = 1.7-2.0), respectively. Patients with immediate post-PMV MVA <1.8 cm(2) showed significantly lower event-free survival rate than those with post-PMV MVA > or =1.8 cm(2) (P < 0.001).

CONCLUSION

Immediate post-PMV MVA> or =1.8 cm(2) was an important predictor of both restenosis- and clinical event-free survival and this value should be considered as a component of optimal result.

Evaluation of mitral stenosis in 2008

Percutaneous mitral valve commissurotomy (PMC) is the treatment of choice for patients with mitral stenosis (MS) and favorable anatomy. Evaluation of MS should answer two questions: is MS severe? And is the valve suitable for PMC? Evaluation of MS severity relies on accurate echocardiographic assessment of the mitral valve area (MVA). Several methods can be used, often in combination. The planimetry is the reference method but must be precisely performed at the tips of the leaflets in a well-oriented plane and thus requires experienced operators. New imaging technologies, such as 3D-echocardiography, MRI or computed tomography may reduce planimetry's operator dependence. The pressure half-time method (PHT) has the merit of simplicity but should be used cautiously in elderly patients or those in atrial fibrillation. It is invalid immediately after PMC but can still be used as a semi-quantitative method: a PHT less than 130 msec is associated with a good valve opening with an excellent specificity and positive predictive value whereas a PHT 130 msec does not allow any conclusion. The continuity equation, easy to perform, may be invalidated by the commonly associated aortic or mitral regurgitation or in case of atrial fibrillation. The PISA method, is reputed technically challenging and requires a direct measurement of angle between the mitral leaflets, although the use of a fixed value of 100 degrees provides an accurate MVA estimation. The main indication of transesophageal echocardiography is the exclusion of left atrial thrombus, which is a contra-indication to PMC as well as a 2/4 or greater mitral regurgitation grade. Two-dimensional-echocardiography allows detailed evaluation of valve morphology, including leaflet thickness and mobility, degree and localization of calcifications, extent of the subvalvular involvement. Unfavorable valve anatomy is associated with a lower rate of PMC success and lower event-free survival. However, given the low predictive value of all anatomic scores, the decision to perform or not the procedure should be based on a global approach taking into account not only the valve anatomy but also individual patients characteristics such as age, rhythm, NYHA class, MVA and the predicted operative mortality based on associated comorbidities.

The impact of mitral valve morphology on the long-term outcome of mitral balloon valvuloplasty

BACKGROUND

The effect of mitral valve morphology (MVM) on the long-term results of mitral balloon valvuloplasty (MBV) is not well established. The aim of the study was to evaluate the impact of MVM on long-term outcome of MBV.

METHODS

Five hundred and eighteen consecutive patients (mean age, 31+/-11 years) who underwent successful MBV were followed up for 0.5-16.5 (mean, 6+/-4.5) years. Patients were divided into two groups according to their mitral echo score (MES) before MBV: group A (n=340; MES<or=8) and group B (n=178; MES>8).

RESULTS

We report the immediate and long-term clinical and echocardiographic results of the above-mentioned 518 consecutive patients. The mitral valve area was significantly larger in group A than in group B, both immediately after MBV (2.0+/-0.3 vs. 1.82+/-0.3 cm2, respectively; P<0.0001) and also at the last follow-up (1.8+/-0.33 vs. 1.5+/-0.33 cm2, respectively; P<0.0001). Restenosis occurred in 38/340 (11%) in group A vs. 73/178 (41%) in group B (P<0.0001). Actuarial freedom from restenosis at 5, 10, 15 years were 92+/-2%, 85+/-3%, 65+/-6% for group A vs. 72+/-4%, 44+/-5%, 9+/-6% for group B (P<0.001). Event-free survival rates at 5, 10, 15 years for group A were 93+/-1%, 88+/-2%, 66+/-6% vs. 82+/-3%, 59+/-6%, 8+/-7% for group B (P<0.0001). Stepwise Cox multivariate regression analysis identified MES, preprocedure functional class, and postprocedure mitral valve area<or=1.8 cm2, as predictors of restenosis (P<0.0001, P=0.014, P=0.0015, respectively); MES and age as predictors of event-free survival (P<0.0001, P<0.0001, respectively).

CONCLUSION

MBV has excellent long-term results in patients with favorable MVM. Favourable MVM is a strong predictor of good long-term outcome.

Long-Term Results (Up to 16.5 Years) of Mitral Balloon Valvuloplasty in a Series of 518 Patients and Predictors of Long-Term Outcome

OBJECTIVES

To assess the long-term results (up to 16.5 years) of mitral balloon valvuloplasty (MBV) and to identify predictors of restenosis and event-free survival.

METHODS AND RESULTS

We report the immediate and long-term clinical and echocardiographic results in 518 patients, mean age 31 +/- 11 years, who underwent successful MBV for severe mitral stenosis (MS) and were followed up for 0.5-16.5 (mean 6 +/- 4.5) years. After MBV, mitral valve area (MVA) increased from 0.84 +/- 0.2 to 1.83 +/- 0.53 cm(2) (P < 0.0001) as measured by catheter and from 0.92 +/- 0.17 to 1.96 +/- 0.29 cm(2) (P < 0.0001) as measured by two-dimensional echo. Restenosis occurred in 111 patients (21%) and it was less frequent in patients with low echo score (11%). Actuarial freedom from restenosis at 5, 10, 15 years was 85 +/- 1%, 70 +/- 3%, and 44 +/- 5%, respectively, and was significantly higher in patients with low echo score. Event-free survival (death, redo MBV, mitral valve replacement, New York Heart Association [NYHA] functional class III or IV) at 5, 10, 15 years was 89 +/- 1%, 79 +/- 2%, 43 +/- 9%, respectively, and was significantly higher for patients with low echo score. Cox regression analysis identified mitral echocardiographic score (MES) > 8 (P < 0.0001), postprocedure mitral valve area (MVA) (P = 0.0015), and preprocedure functional class (P = 0.014) as predictors of restenosis and MES (P < 0.0001) and age (P < 0.0001) and postprocedure MVA (P = 0.015) as predictors of event-free survival.

CONCLUSIONS

MBV provides excellent long-term results for selected patients with MS. The long-term outcome after this procedure can be predicted from baseline clinical and echocardiographic characteristics.

Percutaneous mitral balloon valvotomy

Percutaneous mitral balloon valvotomy (PMBV) was introduced in 1984 by Inoue who developed the procedure as a logical extension of surgical closed commissurotomy. Since then, PMBV has emerged as the treatment of choice for severe pliable rheumatic mitral stenosis (MS). With increasing experience and better selection of patient, the immediate results of the procedure have improved and the rate of complications declined. When the reported complications of PMBV are viewed in aggregate, complications occur at approximately the following rates: mortality (0-0.5%), cerebral accident (0.5-1%), mitral regurgitation (MR) requiring surgery (1.6-3%). These complication rates compare favorably to those reported after surgical commissurotomy. Several randomized trials reported similar hemodynamic results with PMBV and surgical commissurotomy. Restenosis after PMBV ranges from 4 to 70% depending on the patient selection, valve morphology, and duration of follow up. Restenosis was encountered in 21% of the author's series at mean follow-up 6 +/- 4.5 years and the 10 and 15 years restenosis-free survival rates were (70 +/- 3)% and (44 +/- 5)%, respectively, and were significantly higher for patients with favorable mitral morphology (85 +/- 3% and 65 +/- 6%), respectively (P < 0.0001). The 10 and 15 years event-free survival rates were (79 +/- 2)% and (43 +/- 9)% and were significantly higher for patients with favorable mitral morphology (88 +/- 2)% and (66 +/- 6)%, respectively (P < 0.0001). The effect of PMBV on severe pulmonary hypertension, concomitant severe tricuspid regurgitation, left ventricular function, left atrial size, and atrial fibrillation are addressed in this review. In addition, the application of PMBV in specific clinical situations such as in children, during pregnancy and for restenosis is discussed.

Long-term clinical and echocardiographic results after successful mitral balloon valvotomy and predictors of long-term outcome

AIMS

To assess the long-term outcome of mitral balloon valvotomy (MBV) and identify predictors of restenosis- and event-free survival.

METHODS AND RESULTS

We report the immediate and long-term clinical and echocardiographic results in 493 patients, mean age 31+/-11, who underwent successful MBV and were followed-up for 0.5-15 years (median 5+/-3) with clinical and echocardiographic examination. After MBV, mitral valve area increased from 0.84+/-0.2 to 1.83+/-0.53 cm(2) (P<0.0001) as measured by catheter and from 0.92+/-0.17 to 1.96+/-0.29 cm(2) as measured by two-dimensional echo. Restenosis occurred in 86/493 (17.4%) patients and it was less frequent in patients with low echo score. Actuarial freedom from restenosis at 5, 7, 10, and 13 years were 89+/-1, 81+/-2, 68+/-3, and 51+/-6%, respectively, and was significantly higher in patients with low echo score. Event-free survival (death, redo MBV, mitral valve replacement, New York Heart Association functional Class III or IV) at 5, 7, 10, and 13 years were 92+/-1, 87+/-2, 80+/-3, and 74+/-3%, respectively, and was significantly higher for patients with low echo score. Cox regression analysis identified mitral echocardiographic score (MES) >8 as predictors of restenosis (P=0.0004) and MES and age as predictors of event-free survival (P=0.0003 and 0.004, respectively).

CONCLUSION

MBV has excellent long-term results for selected patients with mitral stenosis. The long-term outcome after this procedure can be predicted from baseline clinical and valvular characteristics.

Randomized comparison between Inoue balloon and metallic commissurotome in the treatment of rheumatic mitral stenosis: immediate results and 6-month and 3-year follow-up

The metallic commissurotome (MC) technique is a cheaper alternative to the Inoue balloon (IB) technique for percutaneous mitral valvuloplasty (PMV). There are no randomized trials comparing these techniques with longer follow-up of the patients. The objective of this study was to compare the immediate results and short- and medium-term follow-up of PMV using either the IB or the MC technique. Fifty patients with rheumatic mitral stenosis were randomly assigned to PMV using the IB (n = 27) or the MC (n = 23) technique. There were no significant differences between the groups regarding baseline clinical, echocardiographic, and hemodynamic data. Clinical and echocardiographic follow-up were done 6 months and 3 years after the procedure. The success rate was 100% in the IB group and 91.3% in the MC group (P = 0.15); two patients in the latter group developed mitral regurgitation grade 3/4, requiring elective surgery. The mean final mitral valve area was bigger in the MC group (2.17 +/- 0.13 vs. 2.00 +/- 0.36 cm2; P = 0.04), but after 6-month and 3-year follow-up, this difference was no longer significant (2.06 +/- 0.27 vs. 1.98 +/- 0.38 cm2, P = 0.22, and 1.86 +/- 0.32 vs. 1.87 +/- 0.34 cm2, P = 0.89, respectively). This finding suggests valve stretching as an important mechanism of valve dilation with the MC. Three patients in the MC group and two patients in the IB group (P = 0.65) developed mitral valve restenosis; one of them underwent repeat PMV and the other four, all asymptomatic, were clinically followed. PMV performed either with the IB or the MC technique is effective and provides excellent short- and medium-term outcomes regardless of the technique employed.