Influence of mitral valve morphology on mitral balloon commissurotomy: immediate and six-month results from the NHLBI Balloon Valvuloplasty Registry

Percutaneous transmitral balloon commissurotomy using a single balloon with arteriovenous loop stabilisation: an alternative when there is no Inoue balloon

Background

The Inoue balloon technique is the standard technique for mitral valve balloon commissurotomy at this stage. However, the hardware for this technique is expensive and may not always be available in resource-limited settings.

Objectives

This article reports our experience with percutaneous transmitral balloon commissurotomy using a single balloon (Nucleus) with arteriovenous loop stabilisation.

Methods

Eleven young patients, aged 12–26 years and weighing 23–48 kg, underwent transmitral balloon commissurotomy using the described technique at our centre from April to May 2014.

Results

Mean fluoroscopy time was 22.6 ± 6.4 min (18.5– 30.0). Mean transmitral gradient decreased from 24.1 ± 5.9 (16–35) to 6.6 ± 3.8 (3–14) mmHg, as measured on transoesophageal echocardiography. Mean mitral valve area increased from 0.69 ± 0.13 cm² (range 0.5–0.9) before dilation to 1.44 ± 0.25 cm² (1.1–1.9) after dilation (p < 0.001). Mean estimated pulmonary artery systolic pressure decreased from 110.0 ± 35 mmHg (75–170) before dilation to 28.0 ± 14.4 mmHg (range 10–60) after dilation.

Conclusion

Our modified Nucleus balloon technique for mitral valve dilation in young patients with mitral stenosis is effective and safe. The technique differs from other over-thewire techniques in that it avoids placing stiff wire in the left ventricle. It also offers better balloon stability and control owing to the arteriovenous loop. This technique may be easier for use by paediatric interventionists who might not be familiar with the Inoue balloon technique.

Pathology of Severe Mitral Regurgitation following Balloon Valvuloplasty

This study assessed the mechanism of acute mitral regurgitation following balloon mitral valvuloplasty for the treatment of symptomatic mitral stenosis. We studied 25 patients who required mitral valve replacement for severe mitral regurgitation following balloon mitral valvuloplasty. All the mitral valves studied had features of severe mitral stenosis. Radial tear of the mitral leaflet was responsible for mitral regurgitation in 18 (72%) cases. Of these, 16 involved the anterior mitral leaflet and in 2 cases the posterior mitral leaflet was torn. Three patients (12%) had chordal rupture, whereas in 4 (16%) patients pseudo-orifices were formed. All the excised mitral valves showed significant subvalvular deformity which was underestimated in prevalvuloplasty echocardiography. No other factor was found to be associated with disruption of the valve. Hence, we conclude that cusp deformity and subvalvular pathology are responsible for faulty transmission of forces and improper engagement of the balloon, resulting in disruption of the valvular apparatus. The incidence of severe mitral regurgitation following balloon mitral valvuloplasty might be decreased by appropriate prevalvuloplasty assessment and patient selection.

A differentiated morphological parameter-coding system to describe the suitability of mitral valve stenoses intended for percutaneous valvotomy

Percutaneous balloon-mitral-valvotomy (PBMV) is an alternative to surgery in selected patients with mitral valve (MV) stenosis (MS). Applying echocardiography, suitability for PBMV is assessed by detailed morphological description. Echo-scores alone are suboptimal to describe MV morphology, because single parameters, important for a decision concerning PBMV, are not distinguishable out of a score number. The aim was to design a tool (coding-system), which combines a number for a stenotic MV like scores (for statistical options) and decodable, generally applied parameters describing the MS morphology. The reproducibility of the MS morphology using the coding-system has to be tested in 90 patients. A separate group of 297 patients (pts) with MS, scheduled for PBMV, should be investigated prospectively applying the coding-system and a comparable score. We chose the Wilkins score (WS) as representative of scores. The coding-system is designed as a parameter sequencing set consisting of 6 digits. The first digit indicates a decision code concerning suitability for PBMV. The following 5 digits indicate generally accepted morphological parameters, which are partially also used in the WS. Therefore, the MS morphology can be "read" retrospectively by decoding. 201/297 patients were found suitable for PBMV. Applying the coding-system all 201 suitable patients were correctly distinguished from 96 morphologically unsuitable patients. Astonishingly 48/96 of the rejected patients showed a WS ≤8 whereas 28/201 of the suitable patients demonstrated a WS >8. 25/28 of them showed a successful initial outcome. Applying the generally known threshold of "8" when predicting suitability of a MS, the WS demonstrated an initial success rate of 62 %, sensitivity of 0.87, specificity of 0.45, precision of 0.79, and accuracy of 0.78. Applying the coding-system, the initial success rate was 70.8 %, sensitivity = 0.96, specificity = 1.0, precision = 1.0, and accuracy = 0.97. The coding-system is an advanced diagnostic aid, is statistically applicable, offers a decodable morphological description, includes a decision code regarding suitability for PBMV, and can be used for comparing different groups of patients with MS by calculating "mean morphologies" of groups.

The echo score revisited: Impact of incorporating commissural morphology and leaflet displacement to the prediction of outcome for patients undergoing percutaneous mitral valvuloplasty

BACKGROUND

Current echocardiographic scoring systems for percutaneous mitral valvuloplasty (PMV) have limitations. This study examined new, more quantitative methods for assessing valvular involvement and the combination of parameters that best predicts immediate and long-term outcome after PMV.

METHODS AND RESULTS

Two cohorts (derivation n=204 and validation n=121) of patients with symptomatic mitral stenosis undergoing PMV were studied. Mitral valve morphology was assessed by using both the conventional Wilkins qualitative parameters and novel quantitative parameters, including the ratio between the commissural areas and the maximal excursion of the leaflets from the annulus in diastole. Independent predictors of outcome were assigned a points value proportional to their regression coefficients: mitral valve area ≤1 cm(2) (2), maximum leaflets displacement ≤12 mm (3), commissural area ratio ≥1.25 (3), and subvalvular involvement (3). Three risk groups were defined: low (score of 0-3), intermediate (score of 5), and high (score of 6-11) with observed suboptimal PMV results of 16.9%, 56.3%, and 73.8%, respectively. The use of the same scoring system in the validation cohort yielded suboptimal PMV results of 11.8%, 72.7%, and 87.5% in the low-, intermediate-, and high-risk groups, respectively. The model improved risk classification in comparison with the Wilkins score (net reclassification improvement 45.2%; P<0.0001). Long-term outcome was predicted by age and postprocedural variables, including mitral regurgitation, mean gradient, and pulmonary pressure.

CONCLUSIONS

A scoring system incorporating new quantitative echocardiographic parameters more accurately predicts outcome following PMV than existing models. Long-term post-PMV event-free survival was predicted by age, degree of mitral regurgitation, and postprocedural hemodynamic data.

Comparative study on safety, efficacy, and midterm results of balloon mitral valvotomy performed with triple lumen and double lumen mitral valvotomy catheters

BACKGROUND

The triple lumen Inoue balloon is routinely used for balloon mitral valvotomy (BMV) in India. Its major limitation is the high cost. The double lumen Accura balloon is less expensive, making it an attractive alternative in the developing countries. The study was meant to assess the safety, efficacy and midterm results of Accura balloon with respect to the Inoue balloon.

PATIENTS AND METHODS

816 consecutive patients, who underwent elective BMV in this Institute from 1997 to 2003, were included in the study. The data of 487 patients who underwent BMV with Accura balloon was compared with 329 patients who underwent BMV with Inoue balloon. The clinical, echocardiographic, and hemodynamic data of these patients were analyzed retrospectively to assess the safety and efficacy of Accura balloon with respect to the Inoue balloon.

RESULTS

Immediate procedural success (93.9% in Inoue group and 91.6% in Accura group p. NS) and complications (6.6% in Inoue group and 5.6% in Accura group p. NS) were comparable between the study groups. The two study population had similar restenosis rate and events at 1 year after BMV. Both balloons could be reused multiple times without compromising on the safety and effectiveness. Accura balloons were less costly than Inoue balloon. The reusability with Accura was slightly more and found to be more cost-effective.

CONCLUSIONS

Both Accura and Inoue balloon mitral valvotomy balloons are effective in providing relief from hemodynamically significant mitral stenosis in terms of gain in valve area and reduction in trans mitral gradient. Both groups have similar procedural success and complication rates, restenosis, and follow-up events at 1 year. Both balloons could be reused multiple times and Accura balloon is found to be more cost effective.

Utility of the posterior to anterior mitral valve leaflets length ratio in prediction of outcome of percutaneous balloon mitral valvuloplasty

BACKGROUND

Scoring of mitral stenosis (MS) severity is very important for selection of patients for balloon mitral valvuloplasty (BMV).

OBJECTIVE

We propose a novel yet simple, independent parameter of MS severity based on the posterior mitral valve leaflet to anterior mitral valve leaflet length ratio (PMVL/AMVL length ratio). It could be a useful predictor to outcome of BMV.

SUBJECTS AND METHODS

A total of 106 patients (mean age 29.1 ± 8.6 years) had MS with mitral valve score of eight or less. The length of anterior mitral valve leaflet and posterior mitral valve leaflet were measured. Patients were classified into group with ratio ≥1/2 and group of ratio <1/2. Eighty-five healthy control subjects were studied.

RESULTS

Patients with PMVL/AMVL ratio ≥1/2 post-BMV had lower transmitral gradients (4.5 ± 3.1 mmHg vs. 9.7 ± 2.1 mmHg, P < 0.002) and greater mitral valve area (MVA) (2.09 ± 0.3 cm(2) vs. 1.5 ± 0.2 cm(2) , P < 0.001), lower pulmonary artery systolic pressure (PASP) (23.8 ± 14.3 mmHg vs. 34.2 ± 12.5 mmHg, P < 0.001), left atrial pressure (10.2 ± 6.7 mmHg vs. 18.9 ± 6.4 mmHg, P < 0.001), and lower incidence of de novo or worsening of mild mitral regurgitation (MR; 1.64% vs. 8.9%, 0% vs. 6.6%, P < 0.001). PMVL/AMVL length ratio was positively correlated with post-BMV MVA (r = 0.69, P < 0.002), PASP (r = 0.592, P < 0.003), and negatively correlated with incidence of de novo or worsening of mild MR (r =-0.78, -0.93, P < 0.001). The regression analyses revealed that PMVL/AMVL ratio is the best and a reliable predictor of success and outcome of BMV, hazard ratio (95% confidence interval) 0.12 (0.05-52), P < 0.001.

CONCLUSION

Length ratio of PMVL/AMVL assessment with echocardiography is an excellent simple predictor of post-BMV mitral valve area and the cardiac events.

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.

Validation of a new score for the assessment of mitral stenosis using real-time three-dimensional echocardiography

BACKGROUND

The aim of this study was to validate a new real-time three-dimensional echocardiography (RT3DE) score for evaluating patients with mitral stenosis (MS).

METHODS

A two-staged study was conducted. In the first stage, the feasibility of a new RT3DE score was assessed in 17 patients with MS. The second stage was planned to validate the RT3DE score in 74 consecutive patients undergoing percutaneous mitral valvuloplasty. The new RT3DE score was constructed by dividing each mitral valve (MV) leaflet into 3 scallops and was composed of 31 points (indicating increasing abnormality), including 6 points for thickness, 6 for mobility, 10 for calcification, and 9 for subvalvular apparatus involvement. The total RT3DE score was calculated and defined as mild (<8), moderate (8-13), or severe (>or=14). MV morphology was assessed using Wilkins's score and compared with the new RT3DE score.

RESULTS

In the first stage, the RT3DE score was feasible and easily applied to all patients, with good interobserver and intraobserver agreement. In the second stage, RT3DE improved MV morphologic assessment, particularly for the detection of calcification and commissural splitting. Both scores were correlated for assessment of thickness and calcification (r = 0.63, P < .0001, and r = 0.44, P < .0001, respectively). Predictors of optimal percutaneous mitral valvuloplasty success by Wilkins's score were leaflet calcification and subvalvular apparatus involvement, and those by RT3DE score were leaflet mobility and subvalvular apparatus involvement. The incidence and severity of mitral regurgitation were associated with high-calcification RT3DE score.

CONCLUSION

The new RT3DE score is feasible and highly reproducible for the assessment of MV morphology in patients with MS. It can provide incremental prognostic information in addition to Wilkins's score.

Echocardiographic assessment of mitral valve morphology after Percutaneous Transvenous Mitral Commissurotomy (PTMC)

AIMS

PTMC produces significant changes in mitral valve morphology as improvement in leaflets mobility. The determinants of such improvement have not been assessed before.

METHODS AND RESULTS

The study included 291 symptomatic patients with mitral stenosis undergoing PTMC. Post-PTMC subvalvular splitting area was a determinant of post-PTMC excursion in both the anterior (B 0.16, 95% CI 0.03 to 0.30, p < 0.05) and the posterior (B 0.12, 95% CI 0.01 to 0.24, p < 0.05) leaflets. Another determinant was the post-PTMC transmitral pressure gradient for anterior (B -0.02, 95% CI -0.04 to -0.005, p < 0.01) and posterior (B -0.01, 95% CI -0.04 to -0.005, p < 0.05) leaflets excursion. The relationship between post-PTMC MVA and leaflet excursion was non-linear "S curve". There was a steep increase of both anterior (p, 0.02) and posterior (p, 0.03) leaflets excursion with increased MVA till the MVA reached a value of about 1.5 cm2; after which both linear and S curves became nearly parallel.

CONCLUSION

The improvement in leaflets excursion after PTMC is determined by several morphologic and hemodynamic changes produced in the valve. The increase in MVA improves mobility within limit; after which any further increase in MVA is not associated by a significant improvement in mobility in both leaflets.

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.

Echocardiographic Evaluation of the Mitral Valve Area Before and After Percutaneous Mitral Commissurotomy: The Pressure Half-time Method Revisited

BACKGROUND

Doppler pressure half-time (PHT) is widely used for mitral valve area (MVA) assessment but its accuracy has not been fully evaluated before and after percutaneous mitral commissurotomy (PMC) in a large series of patients.

METHODS

In 120 patients with severe mitral stenosis, MVA(PHT) was prospectively evaluated before and 24 to 48 hours after PMC and compared with 2-dimensional planimetry (MVA(2D)) as a reference method.

RESULTS

After PMC, MVA(2D) significantly increased (1.81 +/- 0.30 vs 1.03 +/- 0.23 cm2, P < .0001), mean transmitral gradient decreased (5 +/- 3 vs 10 +/- 5 mm Hg, P < .0001), and a good valve opening (MVA(2D) > or = 1.5 cm2) was observed in 107 patients (89%). Before PMC, correlation between MVA(PHT) and MVA(2D) was only fair overall (r = 0.52, P < .0001) and weak in subgroups of older patients (> or = 60 years; r = 0.16, P = .37) and in patients in atrial fibrillation (r = 0.38, P < .05). After PMC, MVA(PHT) (1.62 +/- 0.39 cm2) was significantly lower than MVA(2D) (P < .0001) and correlation was poor overall (r = 0.30, P = .0004; mean difference 0.33 +/- 0.30 cm2) and in all subgroups (r < 0.35). However, for the prediction of a good valve opening, a PHT less than 130 milliseconds (observed in 43 patients, 36%) had an excellent specificity (100%) despite a poor sensitivity (44%).

CONCLUSION

For MVA assessment, the PHT method should be used cautiously even before PMC, especially in older patients or those in atrial fibrillation. After PMC, it does not provide an accurate MVA evaluation but can still be used as a semiquantitative method: a PHT less than 130 milliseconds is associated with a good valve opening, which can be useful in difficult cases.

Initial clinical experience with intracardiac echocardiography in guiding balloon mitral valvuloplasty: technique, safety, utility, and limitations

The objective of this study was to examine the feasibility and technique of intracardiac echocardiography during percutaneous balloon mitral valvuloplasty. Echocardiographic imaging is commonly used during mitral valvuloplasty. Intracardiac echocardiography is a newer technology that may provide superior imaging during complex valvular interventions. Intracardiac echocardiography and transthoracic echocardiography were performed in 19 patients undergoing percutaneous balloon mitral valvuloplasty. Intracardiac ultrasound images were obtained via the femoral vein in all patients. Imaging projections and catheter locations that were useful for the performance of mitral valvuloplasty were defined. Intracardiac echocardiography guided transseptal puncture, augmented the assessment of valve apparatus deformity, facilitated balloon positioning across the mitral valve, and permitted postprocedural valvular assessment including identification of mitral regurgitation with color Doppler. Intracardiac echocardiography provided essential imaging guidance and procedural monitoring during percutaneous mitral valvuloplasty.

Echocardiographic Criteria in Selection of Patients for Percutaneous Mitral Commissurotomy

The purpose of this report is to review the role of echocardiography in the selection of patients for percutaneous mitral commissurotomy (PMC). Echocardiography has become the standard for the assessment of the severity of mitral stenosis and of its consequences. PMC is usually performed only in patients with a valve area of < 1.5 cm(2), whereas pulmonary hypertension or spontaneous echo contrast in the left atrium may lead to intervention in patients with few symptoms. The next step of the echocardiographic evaluation is to eliminate contraindications: left atrial thrombosis (by the systematic performance of a transesophageal examination before PMC), mitral regurgitation >/= 2/4, severe aortic valve disease, mixed tricuspid valve disease, and massive or bicommissural calcification. Finally, echocardiography allows the classification of patients into different anatomic groups for prognostic consideration. There is controversy regarding the best echo score system in the prediction of the results of PMC. Scores using a global evaluation of the valve anatomy are the most widely used, whereas more recently, scores taking into account the uneven distribution of the disease have had promising preliminary results. Overall, echo scores are useful criteria for selecting candidates for PMC, but they should be considered together with the other clinical and procedural variables. Thus, echocardiography has an important role in the selection of patients for PMC, as well as for the guidance of the procedure, the evaluation of the results, and surveillance.

Balloon valvuloplasty for mitral stenosis

Balloon mitral valvuloplasty (BMV) for mitral stenosis is a procedure that has evolved significantly since its introduction by Inoue et al. in 1984. This article reviews currently used techniques, advantages, and limitations as well as outcomes in comparison with surgical procedures. Included is a review of imaging techniques that facilitate BMV, such as transesophageal echocardiography and the recently developed tri-dimensional transthoracic echocardiography and intracardiac echocardiography. In a separate section, the application of BMV in specific clinical situations, such as in patients with multivalvular disease, during pregnancy, in children, in the presence of thrombi, and in patients with bioprostheses, is discussed.

Influence of sub valvular pathology on immediate results and follow up events of Inoue balloon mitral valvotomy

We evaluated the influence of sub valvular pathology (SVP) on the immediate results and follow up events of Inoue Balloon Mitral Valvotomy (IBMY) in 206 patients with severe SVP (Group I) and compared their outcome with 206 age and sex matched patients selected from the rest of 619 patients having mild/moderate SVP (Group II). Pre-procedure echocardiographic recordings were reviewed and mitral valve morphology was evaluated using U.S. California Score. The severe SVP group had lower mitral valve areas (MVA) (0.7 cm2 vs. 0.8 cm2) and higher mean pulmonary artery pressure (MPAP) (46.3+/-16.9 mmHg vs. 40.7+/-16.25 mmHg) and mean pulmonary capillary wedge pressure (PCWP) (27.5+/-7.3 mmHg vs. 25.7+/-8.0 mmHg) (p<0.001). IBMV was done using standard technique. The procedure was technically successful in 192/206 patients (93.2%) in group I and 187/206 (91%) in group II (p=ns). The mean transmitral gradient decreased from 24.8+/-7.6 mmHg to 7.46+/-3.4 mmHg while mean PCWP fell from 27.5+/-7.3 mmHg to 12.2+/-5.6 mmHg and MPAP fell from 46.3+/-16.9 mmHg to 23.6+/-12.2 mmHg (p=<0.001). MVA increased from 0.7+/-0.2 cm2 to 1.7+/-0.4 cm2 (p=<0.001). Severe mitral regurgitation (MR) occurred in 2 patients out of which one patient, who had associated coronary artery disease, died post operatively, and moderate MR occurred in 8 patients. The results achieved in patients with severe SVP were not statistically different from those with mild/moderate SVP. The benefits achieved immediate post IBMV were sustained in 184 patients with severe SVP who were available for follow up at a mean duration of 15.2 months (range 3 months to 51 months). Thus IBMV is safe and effective in patients with severe SVP. This group of patients with severe SVP are more hemodynamically deranged pre-BMV and also achieve better hemodynamic benefit compared to those with mild/moderate SVP. Severe SVP does not have any adverse effect either on immediate results (success/occurrence of MR) or on intermediate term follow up.

Comparison of late results of balloon valvotomy in mitral stenosis with versus without mitral regurgitation

Balloon mitral valvotomy (BMV) is safe and effective in patients with mitral stenosis (MS) and coexisting mild mitral regurgitation (MR). Influence of preexisting MR on late outcome of BMV is under evaluation. We included 77 patients without MR and 72 with MR in this study, and compared their immediate and late results in a mean follow-up of 33 +/- 24 months after BMV. Patients with coexisting MR were older and more frequently had significant valvular calcium and atrial fibrillation than patients without MR. After BMV, mitral valve gradient decreased, and cardiac output and mitral valve area by planimetry increased significantly (all p = 0.0001) in both groups. There was no difference in values of mitral valve gradient and cardiac output after BMV between the groups. Mitral valve area was significantly smaller in patients with preexisting MR. During follow-up, there were 11 patients (14%) in the group without MR and 24 (33%) in the group with MR developed cardiac events (p = 0.006). Cumulative event-free survival was 90% at the second year, 87% at the fourth year, and 69% at the sixth year, respectively, in the group without MR versus 78%, 62%, and 37%, respectively, in the group with MR (p = 0.0014). Cox regression showed that preexisting MR was a significant predictor for late cardiac events with a threefold increased hazard risk (p = 0.0025), but age, valvular calcium, echocardiographic score, and cardiac rhythm also played a culpable role. We conclude that preexisting MR is an important risk factor for poor, late outcome of BMV.

A novel prognostic scoring system to predict late outcome after percutaneous balloon valvotomy in patients with severe mitral stenosis

We developed a prognostic scoring system to predict the outcome of follow-up after balloon mitral valvotomy. The system incorporates seven variables before valvotomy: age, New York Heart Association class, fluoroscopic calcification, echocardiographic score, cardiac rhythm, mitral regurgitation, and mitral valve area. Each variable was coded with either 0 or 1 and a total score was between 0 and 7. The study included 150 patients with a mean follow-up of 33 +/- 24 months. In patients with scores of 0-1, 2-3, 4-5, and 6-7, the estimated cardiac event-free survival rate was 97%, 94%, 86%, and 68%, respectively, at 1 year; 95%, 88%, 74%, and 47%, respectively, at 3 years; and 92%, 82%, 61%, and 30%, respectively, 5 years after valvotomy (p = 0.0001). The hazard risk ratio for cardiac events was 1.7 times greater for every step up of the score (p = 0.0001). Our scoring system provides a simple but effective method to predict late outcome of balloon mitral valvotomy.

Percutaneous balloon mitral valvuloplasty

Percutaneous balloon mitral valvuloplasty, first performed by Inoue in 1982, was a rational progression from 4 decades of experience with the blunt surgical dilatation technique of closed mitral commissurotomy. As with surgical commissurotomy, balloon valvuloplasty relieves mitral stenosis by the splitting of fused commissures. A series of studies have shown that balloon valvuloplasty achieves excellent acute hemodynamic results in close to 90% of patients, with a typical 100% increase in mitral valve area. Over the past 15 years since Inoue's first patient, a number of other techniques have been introduced and largely discarded in favor of the original approach. Advances have occurred along the lines of improved noninvasive assessment of mitral valve disease, which have allowed better case selection and prediction of outcome. Follow-up series have shown sustained improvement, with modest rates of complications and restenosis. Comparative studies have shown that balloon valvuloplasty is as effective and safe as surgical commissurotomy, and is a cost-effective procedure of first choice in ideal patients.

A negative transthoracic echocardiogram obviates the need for transesophageal echocardiography in patients with suspected native valve active infective endocarditis

We studied 134 patients with suspected native valve infective endocarditis who underwent transthoracic and transesophageal echocardiography. Our data suggest that in patients without prosthetic valves who have a technically adequate negative transthoracic echocardiogram, transesophageal echocardiography is unlikely to be of incremental benefit in diagnosing endocarditis.

Colour doppler valvar and subvalvar flow diameter imaging versus echo score in mitral stenosis: comparison with type of surgery

OBJECTIVE

To compare the value of echo score with that of Doppler subvalvar flow broadening in deciding the type of mitral stenosis surgery.

PATIENTS

30 patients, mean age 47 years, with severe stenosis undergoing surgery were divided into two groups according to type of surgery: open heart commissurotomy (group 1, n = 12), or prosthesis (group 2, n = 18). A control group of 10 patients with prosthesis served as reference, representing mild stenosis without subvalvar connection.

METHODS

For echo, the score proposed by Wilkins for cross sectional imaging was used. For Doppler, the flow diameters were measured in cm by an independent examiner from the long axis view in early diastole at two levels: (1) at the level of the stenosis (origin flow diameter), and (2) 1.5 cm downstream from the stenosis in the left ventricle (subvalvar flow diameter) with calculation of a Doppler ratio relating these two measurements, expressed as a percentage of broadening. Diagnostic value was compared for both procedures.

RESULTS

There was no significant difference in age, mitral valve areas, or haemodynamics for the two groups. Mean values (SD) were: echo score: group 1, 9.83 (1.26) v group 2, 10.8 (8.1), NS; Doppler ratio %: group 1, 44 (24) v group 2, 12 (21) (P < 0.001); control group: 69 (15). The per cent diagnostic value for an open heart commissurotomy of respective cut off points was: Doppler ratio > 25% (range 71% to 87%); echo score < 10 (range 50% to 75%).

CONCLUSIONS

The new Doppler ratio diagnostic value agreed better with surgical management, repair or prosthesis, in this study. Thus, it appears to better reflect the subvalvar involvement and changes in kinetics than the echo score alone. This easy Doppler method might become a routine examination for follow up of patients with open heart commissurotomy, to avoid performing repeated transoesophageal echocardiography.

Balloon mitral valvotomy: an autopsy study

The autopsy findings in 20 patients who died following percutaneous balloon mitral valvotomy are reported. The procedure was attempted in 508 patients. In 17 of the 20 patients, balloon mitral valvotomy was attempted as a salvage procedure. Ten patients died in the immediate post valvotomy period (within 24 h), seven died within a week and three between 1 to 3 months. In 13 patients, the balloon valvotomy successfully opened out one or both commissures. Interatrial septostomy defects created by the transeptal catheter could be identified in 19 of 20 heart specimens. The size of the defects ranged from small (5 mm) openings to large (15 mm) defects especially with double balloon. Marked mitral valvar thickening with nodular calcification was observed in 16 cases. Significant complications leading to mortality included cardiac tamponade (five cases) due to left ventricle apical perforation (3/5 cases). Mitral valve damage in the form of leaflet tears, chordal rupture and long splits in five cases resulted in significant mitral regurgitation. The leaflet tears resulted in detachment of part of the leaflet from the annulus. A late complication noted was infective endocarditis. Associated pulmonary tuberculosis, chronic obstructive pulmonary disease, respiratory infections and multivalvar diseases also contributed to mortality.

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.

Immediate and late outcome of percutaneous balloon mitral valvotomy in patients with significantly calcified valves

We assessed immediate and late outcome in 55 patients with significantly calcified valves (group 1) after balloon mitral valvotomy and compared the results with those from 60 patients with noncalcified or minimally calcified valves (group 2). After valvotomy, mitral valve area increased from 1.03 +/- 0.30 cm2 to 1.64 +/- 0.35 cm2 (p = 0.0001) by echo planimetry in group 1 but was significantly smaller than the mitral valve area in group 2 after valvotomy (1.94 +/- 0.38 cm2; p = 0.0001). At a mean follow-up period of 30 months (range 2 to 81 months), 51% of patients in group 1 and 83% in group 2 were symptom free (p = 0.0002). In group 2, 15 (27%) patients and in group 2, 4 (7%) patients had cardiac events (p = 0.003). The risk ratio for cardiac events was 4.3 times greater in group 1 than in group 2. In group 1, the risk ratio for cardiac events was 3.2 times higher in patients age > or = 65 years and in patients with atrial fibrillation. The 6-year cumulative cardiac event-free survival rate was 64% in group 1 and 90% in group 2 (p = 0.005). In 75 (65%) patients who had follow-up echocardiographic study (35 in group 1 and 40 in group 2), mitral valve area decreased to 1.48 +/- 0.42 cm2 at follow-up in group 1 (p < 0.01) and to 1.77 +/- 0.50 cm2 in group 2 (p = 0.3). Restenosis occurred in 16 (46%) of 35 patients in group 1 and 10 (25%) of 40 in group 2 (p = 0.06).(ABSTRACT TRUNCATED AT 250 WORDS)

Pathology of mitral valve stenosis and pure mitral regurgitation--Part I

This two-part article examines the histologic and morphologic basis for stenotic and purely regurgitant mitral valves. In Part I, conditions producing mitral valve stenosis are reviewed. In over 99% of stenotic mitral valves, the etiology is rheumatic disease. Other rare causes of mitral stenosis include congenital malformed valves, active infective endocarditis, massive annular calcium, and metabolic or enzymatic abnormalities. In Part II, conditions producing pure mitral regurgitation will be discussed. In contrast to the few causes of mitral stenosis, the causes of pure (no element of stenosis) mitral regurgitation are multiple. Some of the conditions producing pure regurgitation include floppy mitral valves, infective endocarditis, papillary muscle dysfunction, rheumatic disease, and ruptured chordae tendinae.