Factors determining the exercise capacity in mitral stenosis

Left ventricular diastolic function in mitral stenosis

The assessment of left ventricular (LV) function in the setting of mitral stenosis (MS) has been critically examined for decades. Accurate assessment of aberrations in diastolic function is important as these subjects often present with signs and symptoms of heart failure and pulmonary congestion that cannot be solely explained by the severity of mechanical obstruction. Echocardiographic evaluation of diastolic dysfunction includes an evaluation of reduced LV compliance, diminished restoring forces, and enhanced stiffness, which are challenging in the setting of MS owing to altered hemodynamic loading. Conventional echocardiographic and Doppler measures offer limited information. Novel assessments employing speckle tracking echocardiography are relatively less studied. A more comprehensive assessment including clinical evaluation, identification of concomitant disorders, and comorbidities is particularly warranted in older subjects with degenerative MS to suspect diastolic dysfunction and arrive at optimal medical therapy or intervention. This review provides an overview of etiological, pathophysiological, echocardiographic, and invasive assessment of diastolic dysfunction in the setting of MS, with specific focus on strengths and limitations of available echocardiographic and Doppler techniques.

Pulmonary Artery Systolic Pressure Response to Exercise in Patients with Rheumatic Mitral Stenosis: Determinants and Prognostic Value

BACKGROUND

Pulmonary hypertension in response to exercise is a marker of the hemodynamic severity of mitral stenosis (MS). However, the factors related to elevated pulmonary pressure with exercise are not well defined. The aim of this study was to assess the parameters associated with the pulmonary pressure response to exercise in patients with pure rheumatic MS. An additional aim was to determine the impact of exercise-induced pulmonary hypertension on clinical outcome.

METHODS

One hundred thirty patients with MS (94% women; mean age, 45 ± 11 years) underwent exercise echocardiography. A range of echocardiographic parameters were obtained at rest and at peak exercise. Symptom-limited graded ramp bicycle exercise was performed in the supine position. The primary end point was mitral valve intervention, either percutaneous or surgical.

RESULTS

In the overall population, systolic pulmonary artery pressure (SPAP) increased from 38.3 ± 13.4 mm Hg at rest to 65.8 ± 20.7 mm Hg during exercise. Increases in mean mitral gradient, right ventricular function, left atrial volume, and net atrioventricular compliance were independently associated with SPAP at peak exercise, after adjusting for changes in heart rate. During the follow-up period (median, 17 months; range, 1-45 months), 46 adverse clinical events were observed. By multivariate Cox proportional-hazards analysis adjusted for age and sex, SPAP achieved at peak exercise was an important predictor of adverse outcome (adjusted hazard ratio, 1.025; 95% CI, 1.010-1.040; P = .001). New York Heart Association functional class (adjusted hazard ratio, 2.459; 95% CI, 1.509-4.006; P < .001) and the interaction between valve area and net atrioventricular compliance (P = .001) were also significant predictors of adverse events. Time-dependent areas under the receiver operating characteristic curve for the model with SPAP during exercise were better than for the model with SPAP at rest, with a significant improvement from 3 years onward.

CONCLUSIONS

In patients with MS, the pulmonary artery pressure response to exercise is determined by a combination of factors, including transmitral mean gradient at exercise, net atrioventricular compliance, left atrial volume, and right ventricular function. Pulmonary artery pressure at peak exercise is a predictor of clinical outcomes and adds incremental prognostic value beyond that provided by standard resting measurements, including valve area.

Characteristics and Outcomes in a Contemporary Group of Patients With Suspected Significant Mitral Stenosis Undergoing Treadmill Stress Echocardiography

Background:

In contemporary patients with suspected significant mitral stenosis (MS) undergoing rest and treadmill stress echocardiography, we assessed characteristics and factors associated with longer-term survival.

Methods:

We studied 515 consecutive patients (asymptomatic/atypical symptoms, mean left ventricular ejection fraction 58±2%; 43% male) with suspected at least moderate MS ([1] native mitral valve [MV]: resting mean MV gradient ≥5 mm Hg or area ≤1.5 cm 2 and [2] prosthetic valve: resting mean MV gradient ≥5 mm Hg or effective orifice area ≤2 cm) who underwent rest and treadmill stress echocardiography between 1/2003 and 12/2013. MS was categorized as rheumatic (n=170, 33%), postsurgical (prior mitral repair/replacement, n=245, 48%), and primary nonrheumatic (n=100, 19%). Primary outcome was all-cause mortality.

Results:

Mean resting MV gradient and right ventricular systolic pressure were 8.5±3 and 39±13 mm Hg. Patients achieved 95±29% age-sex predicted metabolic equivalents; peak-stress MV gradient and right ventricular systolic pressure were 17±7 and 61±14 mm Hg, respectively. At 54 days (median), 224 (44%) underwent invasive mitral procedure. At 6±4 years, 76 (15%) died. On survival analysis, primary nonrheumatic MS (hazard ratio [HR], 4.92), higher Society of Thoracic Surgeons score (HR, 1.92), lower % age-sex predicted metabolic equivalents (HR, 1.22), and higher peak-stress right ventricular systolic pressure (HR, 1.35), was associated with higher mortality, while invasive mitral procedures were associated with improved survival (HR, 0.67; all P <0.01).

Conclusions:

In asymptomatic patients (or with atypical symptoms) with significant MS undergoing treadmill stress echocardiography, higher mortality was associated with primary nonrheumatic MS, lower % age-sex predicted metabolic equivalents, and higher peak-stress right ventricular systolic pressure, while invasive MV procedures were associated with survival.

Impact of left atrial compliance improvement on functional status after percutaneous mitral valvuloplasty

BACKGROUND

Conventional hemodynamic parameters may not accurately predict symptomatic improvement after percutaneous mitral valvuloplasty (PMV). Changes in left heart chamber compliance following adequate relief o0066 mitral stenosis (MS) may be useful in determining functional capacity after PMV. This study aims to determine the acute effects of PMV on compliance of the left heart and whether its changes relate to the patient's functional capacity.

METHODS

One-hundred thirty-seven patients with severe MS undergoing PMV were enrolled. Left atrial (C_a ) and left ventricular (C_v ) compliance were invasively estimated and net atrioventricular compliance (C_av ) was calculated before and immediately after the procedure. B-type natriuretic peptide (BNP) levels were obtained before and 24 hr after the procedure. The primary endpoint was functional status at 6-month follow-up, and the secondary endpoint was a composite of death, mitral valve (MV) replacement, repeat PMV, new onset of atrial fibrillation, or stroke in patients in whom PMV was successful.

RESULTS

The mean age was 43 ± 12 years, and 119 patients were female (87%). After PMV, C_a and C_av improved significantly from 5.3 [IQR 3.2-8.2] mL/mmHg to 8.7 [5.3-19.2] mL/mmHg (P < 0.001) and 2.2 [1.6-3.4] to 2.8 [2.1-4.1] mL/mmHg (P < 0.001), respectively, whereas C_v did not change (4.6 [3.2-6.8] to 4.4 [3.1-5.6]; P = 0.637). Plasma BNP levels significantly decreased after PMV, with no correlation between its variation and changes in left chamber compliance. At 6-month follow-up, NYHA functional class remained unchanged in 32 patients (23%). By multivariable analyses, changes in C_a immediately after PMV (adjusted OR 1.42; 95% CI 95% 1.02 to 1.97; P = 0.037) and younger age (adjusted OR 0.95; CI 95% 0.92-0.98; P = 0.004), predicted improvement in functional capacity at 6-month follow-up, independent of postprocedural data. The secondary endpoint were predicted by post-PMV mean gradient (adjusted HR 1.363; 95% CI 95% 1.027-1.809; P = 0.032), and lack of functional improvement at 6-month follow-up (adjusted HR 4.959; 95% 1.708-14.403; P = 0.003).

CONCLUSIONS

C_a and C_av increase significantly after PMV with no change in C_v . The improvement of C_a is an important predictor of functional status at 6-month follow up, independently of other hemodynamic data. Postprocedural mean gradient and lack of short-term symptomatic improvement were predictors of adverse outcome.

Variable Hemodynamic Responses during Diastolic Stress Echocardiography in Patients Who Have Relaxation Abnormality with Possible Elevated Filling Pressure

BACKGROUND AND OBJECTIVES

The clinical characteristics of patients with diastolic dysfunction characterized by a relaxation abnormality with possible elevated filling pressure is remain to be determined. We sought to test whether diastolic stress echocardiography (DSE) is useful for characterization of these patients.

METHODS

A total of 120 patients (58 men, mean age of 64±7 years) with E/A ratio <1.0 (mean±SD, 0.7±0.1) and 10≤ E/e' <15 at rest echocardiography was enrolled prospectively for supine bicycle exercise up to 50 W.

RESULTS

During exercise, 47 patients (39%) showed high left ventricular filling pressure (E/e' >15, hLVFP) and 40 (30%) developed exercise-induced pulmonary hypertension (systolic pulomary arterial pressure >50 mmHg, EiPH) without hLVFP. The remaining 33 patients did not show hLVFP or EiPH. The incidence of EiPH with hLVFP was 21% (25/120). By multivariate analysis, age (odds ratio [OR], 1.07; 95% confidence interval [CI], 1.00-1.13; p=0.039) and systolic pulmonary artery pressure at rest (OR, 1.14; 95% CI, 1.02-1.27; p=0.02) were associated with EiPH, whereas late diastolic transmitral velocity (OR, 1.04; 95% CI, 1.00-1.08; p=0.03) and diastolic blood pressure (OR, 0.94; 95% CI, 0.90-0.99; p=0.02) were associated with hLVFP during exercise.

CONCLUSIONS

Patients with relaxation abnormality and possibly hLVFP showed markedly heterogeneous hemodynamic changes during low-level exercise and DSE was useful to characterize these patients.

Decreases in left atrial compliance during early-stage exercise are related to exercise intolerance in asymptomatic significant mitral stenosis

BACKGROUND

Doppler-driven net atrioventricular compliance (C_n ), which represents left atrial (LA) compliance, is an important determinant of pulmonary hypertension in mitral stenosis (MS).

HYPOTHESIS

We hypothesized that decreases in C_n during early-stage exercise underlie exercise intolerance in patients with MS.

METHODS

Thirty-three asymptomatic patients with significant MS (valve area 1.24 ± 0.16 cm² ) underwent resting and bicycle exercise echocardiography. LA compliance and conventional parameters were assessed at each workload. The patients were classified into two groups based on whether they developed dyspnea during exercise: an exercise-intolerance group (n = 22) and an exercise-tolerance group (n = 11). Moreover, "50 W" was defined as an early exercise stage.

RESULTS

Although the groups had similar resting characteristics, there were striking differences in their echocardiographic parameters from the early stages of exercise. The relative C_n decrease at 50 W (expressed as a percentage of the resting C_n ) was significantly greater in the exercise-intolerance group (70.3 ± 15.4% vs 49.7 ± 9.7%, P < .001). The overall decrease in relative C_n was significantly greater in the exercise-intolerance group (P = .0005). Furthermore, differences in the trends in this parameter were observed between the two groups (P < .0001 for interaction). Multivariate analysis revealed that the relative C_n decrease at 50 W was an independent predictor of exercise intolerance (adjusted OR 1.105, 95% CI 1.030-1.184) after adjustment for other conventional parameters.

CONCLUSIONS

Decreases in C_n during early-stage exercise are an important mechanism underlying exercise intolerance in MS.

Predictors of Very Late Events After Percutaneous Mitral Valvuloplasty in Patients With Mitral Stenosis

Data on long-term outcomes of percutaneous mitral valvuloplasty (PMV) are still scarce. In addition, the persistence of pulmonary hypertension (PH) after PMV is a complication for which mechanisms and prognostic implications are unclear. Our aims were (1) to report the long-term outcomes of patients with rheumatic mitral stenosis treated with PMV; (2) to determine the risk factors for long-term poor outcomes; and (3) to analyze the prevalence and predictors of persistent PH. We prospectively enrolled 532 patients who underwent PMV from 1987 to 2011 at 2 hospitals. The following end points were assessed after PMV: all-cause mortality, mitral reintervention, a composite end point of all-cause mortality and mitral reintervention, and PH persistence. Survival status was available for 97% patients; the median follow-up was 10 years (interquartile range 4 to 18 years). Procedural success was achieved in 85% patients. During the follow-up, 21% patients died and 27% required mitral reintervention. Before PMV, 74% patients had PH that persisted after PMV in 45% of patients (p <0.001). Unfavorable valve anatomy (Wilkins score >8) and post-PMV mean pulmonary arterial pressure (PAP) were independent predictors of all-cause mortality, mitral reintervention, and the composite end point. Post-PMV mean PAP was significantly correlated with a mitral valve area (MVA) <2.5 cm(2) (p <0.001); in addition, on the echocardiographic follow-up, MVA was an independent predictor of systolic PAP (p <0.001). In conclusion, PMV represents an advantageous therapeutic option for patients with mitral stenosis in terms of long-term outcomes. Unfavorable valve anatomy and persistent PH were the most important predictors of long-term outcomes. The persistence of PH is associated with the MVA obtained after PMV.

Stress echocardiographic assessment of mitral valve function repaired using rough-zone trimming

Background

We invented novel mitral valve repair technique; rough-zone trimming procedure (RZT) for anterior mitral valve prolapse. Prolapse site was resected in obtuse triangle shape and sutured edges to creates deep coaptation and improves regurgitation. Though it is simple and reproducible technique, functional mitral stenosis is a risk. Valve function and hemodynamics were investigated using dobutamine stress echocardiography (DSE) in patients after mitral valve repair using RZT.

Methods

Patients underwent RZT for the anterior mitral valve (AML, n = 10), quadrangular resection (QR) of the posterior mitral valve (PML; n = 4), RZT + QR of bileaflet valves (bileaflet; n = 4) and healthy individuals (control; n = 10) and were assessed by DSE (doses up to 20 μg/Kg/min). Echocardiographic data including mitral valve area (MVA), mitral valve mean pressure gradient (MVmeanPG), and systolic pulmonary artery pressure (sPAP) were measured at rest and at peak stress.

Results

Rest/stress MVA (cm²), MVmeanPG (mmHg) and sPAP (mmHg) were 2.8 ± 0.4 and 3.4 ± 0.3, 3.3 ± 1.1 and 7.4 ± 4.1, and 25.7 ± 4.7and 49.1 ± 4.1, respectively, in the AML group. Dobutamine stress increased all parameters but not to pathological levels. The results were similar to those of the other groups after mitral valve repair, whereas MVA was larger and MVmeanPG was lower in the control than in the AML group.

Conclusions

Valve repair using RZT does not pathologically obstruct the mitral valve, either at baseline or during dobutamine stress, and does not affect valve hemodynamics and reserve.

Impact of net atrioventricular compliance on clinical outcome in mitral stenosis

BACKGROUND

Net atrioventricular compliance (Cn) has been reported to be an important determinant of pulmonary hypertension in mitral stenosis (MS). We hypothesized that it may be useful in assessing prognosis because Cn reflects hemodynamic consequences of MS. To date, limited data with an assumed Cn cutoff have indicated the need for larger prospective studies. This prospective study was designed to determine the impact of Cn on clinical outcome and its contribution to pulmonary pressure in MS. In addition, we aimed to identify a cutoff value of Cn for outcome prediction in this setting.

METHODS AND RESULTS

A total of 128 patients with rheumatic MS without other significant valve disease were prospectively enrolled. Comprehensive echocardiography was performed and Doppler-derived Cn estimated using a previously validated equation. The end point was either mitral valve intervention or death. Cn was an important predictor of pulmonary pressure, regardless of classic measures of MS severity. During a median follow-up of 22 months, the end point was reached in 45 patients (35%). Baseline Cn predicted outcome, adding prognostic information beyond that provided by mitral valve area and functional status. Cn ≤4 mL/mm Hg best predicted unfavorable outcome in derivation and validation sets. A subgroup analysis including only initially asymptomatic patients with moderate to severe MS without initial indication for intervention (40.6% of total) demonstrated that baseline Cn predicted subsequent adverse outcome even after adjustment for classic measures of hemodynamic MS severity (hazard ratio, 0.33; 95% confidence interval, 0.14-0.79; P=0.013).

CONCLUSIONS

Cn contributes to pulmonary hypertension beyond stenosis severity itself. In a wide spectrum of MS severity, Cn is a powerful predictor of adverse outcome, adding prognostic value to clinical data and mitral valve area. Importantly, baseline Cn predicts a progressive course with subsequent need for intervention in initially asymptomatic patients. Cn assessment therefore has potential value for clinical risk stratification and monitoring in MS patients.

The role of exercise echocardiography in the management of mitral valve disease

PURPOSE

Exercise echocardiography can assess the dynamic component of mitral valve (MV) disease and may therefore be helpful for the clinical decision-making by the heart team. The purpose of this study is to determine the role of exercise echocardiography in the management of disproportionately symptomatic or otherwise atypical patients with mitral regurgitation (MR) and stenosis (MS) in clinical practice.

METHODS

Data of 14 MR and 14 MS patients, including echocardiograms at rest, were presented retrospectively to an experienced heart team to determine treatment strategy. Subsequently, exercise echo data were provided whereupon once again the treatment strategy was determined. This resulted in: value of exercise echo by means of 1) alteration or 2) confirmation of treatment strategy or 3) no additional value.

RESULTS

During exercise the echocardiographic severity of MV disease increased in 9 (64 %) MR and 8 (57 %) MS patients. Based upon alteration or confirmation of the treatment strategy, the value of exercise echocardiography in the management of MR and MS was 86 % and 57 %, respectively.

CONCLUSION

This study showed that physical exercise echo can have an important role in the clinical decision-making of challenging patients with MV disease. Exercise echocardiography had additional value to the treatment strategy in 71 % of these patients.

Serum N-terminal brain natriuretic peptide indicates exercise induced augmentation of pulmonary artery pressure in patients with mitral stenosis

INTRODUCTION

To determine whether elevated N-terminal pro-BNP (NT pro-BNP) predicts pulmonary artery systolic pressure increase on exercise stress echocardiography in asymptomatic or mildly symptomatic patients with moderate to severe mitral stenosis.

METHODS AND RESULTS

Forty-one asymptomatic or mildly symptomatic patients with moderate to severe mitral stenosis and 21 age- and sex-matched healthy subjects. Transthoracic echocardiography was performed in all patients to assess the severity of the valve disease and to measure pulmonary artery pressure before and immediately after treadmill exercise. Blood samples for NT pro-BNP were also collected before and immediately after treadmill exercise at the time of echocardiographic examination. The plasma concentrations of NT pro-BNP levels were significantly higher in patients with mitral stenosis than in control subjects before and after exercise (P < 0.001). Patients with atrial fibrillation had significantly higher NT pro-BNP levels compared to those with sinus rhythm (P < 0.001). Pre- and postexercise NT pro-BNP levels correlated statistically significantly with the left atrial (LA) dimension, right ventricle enddiastolic diameter, exercise duration, heart rate, rest, and exercise pulmonary artery systolic pressure, after exercise mitral valve mean gradient. Area under the receiver-operating characteristic curve for NT pro-BNP as an exercise induced augmentation of pulmonary artery pressure was 0.78. Using an optimized cutoff value of 251 pg/mL for NT pro-BNP, sensitivity was 89.47%. The independent determinants of higher pulmonary artery pressure were LA diameter and pretest NT pro-BNP levels in multivariante analysis.

CONCLUSION

NT pro-BNP levels correlate with functional class and echocardiographic findings in patients with mitral stenosis and indicate exercise induced augmentation of peak PAP > 60 mmHg. (Echocardiography 2011;28:8-14).

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.

Echocardiographic and hemodynamic findings in patients with mitral stenosis undergoing percutaneous mitral commissurotomy comparing those with chronic atrial fibrillation versus those with normal sinus rhythm

Chronic atrial fibrillation (AF) is common in patients with mitral stenosis (MS). Because AF induces electrical and mechanical remodeling of the left atrium, left atrial (LA) compliance is likely to be changed in its presence. This study was performed to investigate the influence of AF on LA compliance in patients with moderate to severe MS. Data were analyzed for 356 patients (282 women; mean age 40 +/- 11 years; range 17 to approximately 71) who were registered in the percutaneous mitral commissurotomy database. Mean LA pressure was lower (21 +/- 7 vs 26 +/- 8 mm Hg; p <0.001), but LA volume was higher in the AF than sinus-rhythm group (126 +/- 62 vs 74 +/- 27 ml; p <0.001), indicating higher LA compliance, which was further confirmed by lower LA v wave at catheterization in the AF group (27 +/- 9 for AF vs 32 +/- 10 mm Hg for sinus rhythm; p <0.001). In conclusion, the presence of AF has a significant influence on LA compliance in patients with moderate to severe MS.

Mitral Valve Resistance as a Determinant of Resting and Stress Pulmonary Artery Pressure in Patients with Mitral Stenosis: A Dobutamine Stress Study

BACKGROUND

Severity of mitral stenosis (MS) is assessed by means of mitral valve area and mean transmitral gradient. However, these conventional stenosis indexes poorly reflect the major hemodynamic consequence of MS, which is increase in pulmonary artery pressure (PAP). Valve resistance (VR) is a physiologic expression of stenosis because it incorporates both the pressure gradient and flow data. Previously, in patients with aortic stenosis, hemodynamic burden on the left ventricle has been shown to be closely related to aortic VR but not to aortic valve area. Accordingly, we hypothesized that mitral VR may also better reflect the hemodynamic burden of MS and, hence, be an important determinant of PAP in patients with MS. This study sought to evaluate the relation between several echocardiographic parameters of MS severity, in particular mitral VR and the resting and stress PAP in patients with MS. Determinants of exercise capacity were also assessed.

METHODS

Twenty patients with pure MS were studied by Doppler echocardiography. Mitral valve area, mean transmitral gradient, mitral VR, net atrioventricular compliance, and left atrial diameter were derived from resting Doppler echocardiographic examination as possible determinants of resting and stress PAP. PAP was measured by Doppler echocardiography at rest and during dobutamine-induced stress. Patients completed a symptom-limited exercise test to determine exercise capacity. Determinants of resting and stress PAP and exercise capacity were analyzed.

RESULTS

Systolic PAP increased significantly from 39.2 +/- 9.4 mm Hg at rest to 59.5 +/- 18.4 mm Hg during dobutamine-induced stress. Mitral VR was the most closely correlated stenosis index with the resting and stress PAP (r = 0.80, P < .001 and r = 0.93, P < .001, respectively) and it was an independent predictor for both with multivariate analysis. Exercise capacity was mostly and equally correlated with stress PAP (r = -0.62, P = .004) and mitral VR (r = -0.62, P = .004). Multivariate analysis revealed stress PAP as the only significant independent predictor of exercise capacity.

CONCLUSION

Mitral VR is the strongest and the independent predictor of both resting and stress PAP in patients with MS and by this aspect it is superior to mitral valve area and mean transmitral gradient in the expression of stenosis severity. These results underline the importance of mitral VR as a severity index in patients with MS.

The impact of patient–prosthesis mismatch on late outcomes after mitral valve replacement

OBJECTIVES

The incidence of patient-prosthesis mismatch after mitral valve replacement and its effect on late outcomes have remained unclear. This study was conducted to determine the impact of patient-prosthesis mismatch on recurrent congestive heart failure, postoperative pulmonary hypertension, and late survival after mitral valve replacement.

METHODS

Between 1985 and 2005, 884 patients, with a mean age 63 +/- 12 years, underwent mitral valve replacement (657 mechanical, 227 bioprosthesis) with contemporary prostheses. Mean clinical and echocardiographic follow-up was 5.1 +/- 4.1 years (4344 patient-years). Patient-prosthesis mismatch was defined as an indexed effective orifice area of 1.25 cm2/m2 or less. Parametric and nonparametric analyses were used to determine predictors of outcomes.

RESULTS

The incidence of patient-prosthesis mismatch was 32%. Predictors of recurrent congestive heart failure included low indexed effective orifice area, low ejection fraction, elevated postoperative mean mitral gradient, and use of a bioprosthesis (P < or = .05). Postoperative pulmonary hypertension was associated with small mitral size, elevated mean mitral gradient, low ejection fraction, and atrial fibrillation (P < or = .05); indexed effective orifice area did not predict postoperative pulmonary hypertension (P = .89). Poor late survival was predicted by low indexed effective orifice area (< or =1.25 cm2/m2), New York Heart Association class 3 or 4, elevated right ventricular pressure, stroke, older age, coronary artery disease, and bioprosthesis use (P < or = .05). Survival for patients with patient-prosthesis mismatch versus those without patient-prosthesis mismatch at 1, 3, 5, and 10 years was 91% versus 95%, 85% versus 90%, 78% versus 86%, and 65% versus 75%, respectively (P = .05).

CONCLUSIONS

Patient-prosthesis mismatch after mitral valve replacement is not uncommon; it is associated with recurrence of congestive heart failure and postoperative pulmonary hypertension and independently affected late survival. This study emphasizes the importance of implanting a sufficiently large prosthesis in adult patients undergoing mitral valve replacement.

Impact of valve prosthesis-patient mismatch on pulmonary arterial pressure after mitral valve replacement

OBJECTIVES

We sought to determine the impact of valve prosthesis-patient mismatch (PPM) on pulmonary arterial (PA) pressure after mitral valve replacement (MVR).

BACKGROUND

Pulmonary arterial hypertension is a serious complication of mitral valve disease, and it is a major risk factor for poor outcome after MVR. We hypothesized that valve PPM might be a determinant of PA hypertension after MVR.

METHODS

Systolic PA pressure was measured by Doppler echocardiography in 56 patients with normally functioning mitral prosthetic valves. Mitral valve effective orifice area (EOA) was determined by the continuity equation and indexed for body surface area.

RESULTS

Thirty patients (54%) had PA hypertension defined as systolic PA pressure >40 mm Hg, whereas 40 patients (71%) had PPM defined as an indexed EOA < or =1.2 cm(2)/m(2). There was a significant correlation (r = 0.64) between systolic PA pressure and indexed EOA. The average systolic PA pressure and prevalence of PA hypertension were 34 +/- 8 mm Hg and 19% in patients with no PPM versus 46 +/- 8 mm Hg and 68% in patients with PPM (p < 0.001). In multivariate analysis, the indexed EOA was by far the strongest predictor of systolic PA pressure.

CONCLUSIONS

Persistent PA hypertension is frequent after MVR and strongly associated with the presence of PPM. The clinical implications of these findings are important given that PPM can largely be avoided by using a simple prospective strategy at the time of operation.

Magnitude of left atrial V wave is the determinant of exercise capacity in patients with mitral stenosis

A large left atrial (LA) V wave can be observed in patients with pure mitral stenosis (MS) due to decreased LA compliance. Based on the hypothesis that exercise capacity may correlate with the magnitude of the LA V wave in patients with MS, symptom-limited exercise testing and right and left heart catheterization were performed in 28 patients. The results show that the magnitude of the LA V wave (p = 0.02) was the strongest predictor of the exercise duration, suggesting that LA compliance may be an important contributing factor in determination of exercise capacity in patients with MS.

Value of exercise echocardiography in rheumatic mitral stenosis with and without significant mitral regurgitation

Patients with rheumatic mitral valve disease (n = 48) underwent treadmill stress echocardiography and were classified as those with mitral stenosis (n = 24) or those with mitral regurgitation with mild mitral stenosis (n = 24). Despite marked differences in mitral valve area (1.1 +/- 0.3 vs 2.1 +/- 0.6 cm(2), respectively; p <0.0001), systolic tricuspid gradients were similar both at rest (37 +/- 11 vs 37 +/- 13 mm Hg) and at peak exercise (60 +/- 16 vs 55 +/- 13 mm Hg, respectively). Following stress echocardiography, an invasive procedure or modification of medical treatment was performed or recommended in 51% of the study patients.

Outcome of significant functional tricuspid regurgitation after percutaneous mitral valvuloplasty

BACKGROUND

The outcome of significant functional tricuspid regurgitation (TR) associated with mitral stenosis (MS) after percutaneous mitral valvuloplasty (PMV) remains to be clarified.

METHODS

From 265 patients who underwent PMV at our institution from 1995 to 2000 and who were regularly observed, we selected 71 patients (55 women, mean age 43 +/- 11 years) who showed significant moderate to severe functional TR before PMV. We analyzed data from the echocardiograms performed before, 24 hours after, and long after the intervention (29 +/- 12 months) and analyzed clinical outcomes. Resolution of TR was defined as trace or mild TR on the follow-up color Doppler study.

RESULTS

Patients with moderate to severe TR showed more severe MS and pulmonary hypertension and more atrial fibrillation than patients with less than moderate TR. TR was resolved on the follow-up echocardiography in 23 of the 71 patients with significant TR before PMV (32%). The TR jet area before PMV (P <.05) and the late decrement of peak transmitral pressure gradient (P <.01) were independent determinants of resolution. TR was resolved in only 6.7% of patients (1/15) with an unsuccessful long-term PMV result, but was resolved in 39% of patients (22/56) with a successful long-term result (P <.05). During the clinical follow-up period (mean length 38 +/- 20 months), 4 patients underwent open heart surgery 24 to 39 months after PMV, and there was no overall mortality.

CONCLUSIONS

Significant functional TR was associated with more severe MS, and it could be diminished when the transmitral pressure gradient was sufficiently relieved with PMV.