Assessment of myocardial fibrosis by late gadolinium enhancement imaging and biomarkers of collagen metabolism in chronic rheumatic mitral regurgitation.

BACKGROUND: In chronic rheumatic mitral regurgitation (CRMR), involvement of the myocardium in the rheumatic process has been controversial. Therefore, we sought to study the presence of fibrosis using late gadolinium enhancement cardiac magnetic resonance imaging (LGE-CMR) and biomarkers of collagen turnover in CRMR. METHODS: Twenty-two patients with CRMR underwent CMR and echocardiography. Serum concentrations of matrix metalloproteinase- 1 (MMP-1), tissue inhibitor of MMP-1 (TIMP- 1), MMP-1-to-TIMP-1 ratio, procollagen III N-terminal pro-peptide (PIIINP) and procollagen type IC peptide (PIP) were measured. RESULTS: Four patients had fibrosis on LGE-CMR. PICP and PIIINP concentrations were similar to those of the controls, however MMP-1 concentration was increased compared to that of the controls (log MMP-1 3.5 ± 0.7 vs 2.7 ± 0.9, p = 0.02). There was increased MMP-1 activity as the MMP-1-to- TIMP-1 ratio was higher in CRMR patients compared to the controls ( -1.2 ± 0.6 vs -2.1 ± 0.89, p = 0.002). CONCLUSIONS: Myocardial fibrosis was rare in CRMR patients. CRMR is likely a disease characterised by the predominance of collagen degradation rather than increased synthesis and myocardial fibrosis.

Assessment of insulin-like growth factor-1 (IGF-I) level in patients with rheumatic mitral stenosis.

OBJECTIVES: Insulin-like growth factor-1 may serve some regulatory function in the immune system. Rheumatic mitral stenosis is related to autoimmune heart valve damage after streptococcal infection. The aim of this study was to assess the level of insulin-like growth factor-1 and its correlation with the Wilkins score in patients with rheumatic mitral stenosis. METHODS: A total of 65 patients with rheumatic mitral stenosis and 62 age- and sex-matched control subjects were enrolled in this study. All subjects underwent transthoracic echocardiography. The mitral valve area and Wilkins score were evaluated for all patients. Biochemical parameters and serum insulin-like growth factor-1 levels were measured. RESULTS: Demographic data were similar in the rheumatic mitral stenosis and control groups. The mean mitral valve area was 1.6±0.4 cm2 in the rheumatic mitral stenosis group. The level of insulin-like growth factor-1 was significantly higher in the rheumatic mitral stenosis group than in the control group (104 (55.6-267) versus 79.1 (23.0-244.0) ng/ml; p=0.039). There was a significant moderate positive correlation between insulin-like growth factor-1 and thickening of leaflets score of Wilkins (r=0.541, p<0.001). CONCLUSIONS: The present study demonstrated that serum insulin-like growth factor-1 levels were significantly higher in the rheumatic mitral stenosis group compared with control subjects and that insulin-like growth factor-1 level was also correlated with the Wilkins score. It can be suggested that there may be a link between insulin-like growth factor-1 level and immune pathogenesis of rheumatic mitral stenosis.

Increased mean platelet volume in rheumatic mitral stenosis: assessment of clinical and echocardiographic determinants.

BACKGROUND AND AIM: The aim of this study was to investigate mean platelet volume (MPV) in patients with rheumatic mitral stenosis (RMS) and to define the determinants of a possible platelet activation reflected as platelet volume enlargement. METHODS: Peripheral venous plasma value of MPV was measured in 84 consecutive patients (16 men, 68 women; mean age ± SD = 44 ± 13 years) with RMS who had no left atrial thrombus by transoesophageal echocardiography. The control group consisted of 32 healthy subjects (nine men, 23 women; mean age ± SD = 38 ± 7 years). RESULTS: The patients had significantly higher MPV values (mean ± SD = 10.07 ± 0.58 fL) compared to the healthy subjects (mean ± SD = 8.15 ± 0.60 fL, p < 0.001). Among many clinical and echocardiographic variables, left atrial spontaneous echo contrast-positivity (beta = 0.426, p < 0.001) and severe mitral regurgitation (beta = 0.577, p < 0.001) appeared as significant predictors of platelet enlargement in RMS in multiple linear regression analysis. CONCLUSIONS: Patients with RMS have increased platelet activity reflected as elevated MPV; and the coexistence of severe mitral regurgitation and presence of left atrial spontaneous echo contrast are determinants of this increment.

Three-dimensional echocardiographic assessment before and after percutaneous transvenous mitral commissurotomy in patients with rheumatic mitral stenosis.

BACKGROUND AND AIM OF THE STUDY: Real-time three-dimensional transthoracic echocardiography (RT3DE) is a relatively recent imaging technique that provides excellent image quality of the mitral valve. It has been suggested that this new echocardiographic modality, which allows a precise cross-section of the mitral orifice at the tips of the leaflets with correct plane orientation, may provide a more accurate assessment of rheumatic mitral stenosis (MS) than two-dimensional echocardiography (2DE), before and after percutaneous transvenous mitral commissurotomy (PTMC). METHODS: A total of 50 patients with symptomatic mitral stenosis who underwent PTMC was evaluated prospectively. Patients in all age groups, with evidence of severe MS admitted to the authors' institution, in whom PTMC was feasible were included. RESULTS: A good valve opening was observed in 45 patients (90%). The mitral valve area (MVA) assessed before PTMC with 3DE (3D-MVA) correlated well with that assessed with 2DE (2D-MVA) (0.85 +/- 0.12 cm2 versus 0.86 +/- 0.13 cm2, p < 0.001); the mean difference between methods was small (0.01 +/- 0.11 cm2) and correlation excellent (r = 0.64, p < 0.001). After PTMC, values of 3D-MVA did not differ from, and correlated well with, values of 2D-MVA (1.79 +/- 0.20 cm2 versus 1.74 +/- 0.18 cm2, p = 0.006); the mean difference between methods was small (0.05 +/- 0.02 cm2) and correlation excellent (r = 0.76, p = 0.0001). Before PTMC, Bland-Altman analysis showed a good agreement between methods (mean difference -0.01 +/- 0.11 cm2, lower limit -0.24, upper limit 0.22). After PTMC, Bland-Altman analysis showed a good agreement between methods (mean difference -0.05 +/- 0.13 cm2, lower limit -0.3, upper limit 0.2). Evaluation of the commissural opening after PTMC, using RT3DE, showed that excellent commissural evaluation was possible in all patients. Compared with RT3DE, an underestimation of the degree of commissural fusion using 2DE was observed in 32%, with a weak agreement between methods. CONCLUSION: RT3DE provided accurate measurements of MVA, similar to 2D planimetry. RT3DE also improved the description of valvular anatomy and provided a unique assessment of the extent of commissural splitting.

Assessment of right atrial pressure using echocardiography and correlation with catheterization.

PURPOSE: Right ventricular systolic pressure is crucial for both treatment and prognosis of cardiovascular and pulmonary diseases. The proper measurement of right ventricular systolic pressure depends on an accurate estimation of right atrial pressure (RAP). There is no standard method for estimating RAP noninvasively. The purpose of this study was to compare different noninvasive methods, namely, inferior vena cava (IVC) size and inspiratory collapse, tissue Doppler derived E/E' (TV E/E') for estimating RAP, and their correlation with catheter-based measurements in patients with mitral valve stenosis with atrial fibrillation (AF) or normal sinus rhythm (NSR). METHODS: The study group consisted of 39 patients (13 men, mean age 58.9 ± 11.8 years) with rheumatic mitral valve stenosis. We performed cardiac catheterization and transthoracic echocardiography on all patients. RESULTS: Mean RAP measured by catheterization was 9.7 ± 3.8 mmHg. No correlation was found between RAP and TV E/E' ratio, but there was a significant correlation between RAP and IVC diameter (r = 0.51, p < 0.05). Seventeen patients (43.6%) were in AF and 22 patients (56.4%) were in NSR. There was no correlation between TV E/E' ratio and RAP in patients with AF and in patients with NSR. RAP was correlated with collapsibility index in patients with AF (r = 0.56, p < 0.05). RAP was significantly correlated with IVC diameter (r = 0.62, p < 0.005) and collapsibility index (r = 0.49, p < 0.05) in patients with NSR. CONCLUSIONS: The combination of IVC diameter and collapsibility index is a simple a semiquantitative approach that might provide a better estimation of RAP.

The subvalvular apparatus in rheumatic mitral stenosis: methods of assessment and therapeutic implications.

The assessment of the structure and function of the subvalvular apparatus (SVA) in patients with rheumatic mitral stenosis (MS) is complex, yet is of major importance prior to therapeutic decision making. Currently available methods of assessment are neither sufficiently accurate nor feasible. We review anatomic and functional aspects of the SVA and define SVA involvement in rheumatic MS. The role of various noninvasive and invasive methods for evaluating the integrity and function of SVA in rheumatic MS, as well as clinical implications and pitfalls in assessment of SVA are also discussed.

Assessment of mitral valve volume by quantitative three-dimensional echocardiography in patients with rheumatic mitral valve stenosis.

BACKGROUND: Thickening of mitral leaflets in rheumatic mitral valve stenosis is well described in necropsy studies; however, volume computation of the thickening mitral leaflets has not been attempted. 4trial fibrillation is one of the complications of rheumatic mitral stenosis. Quantitative assessment of thickened mitral valve and its relation to clinical complications is clinically desirable. HYPOTHESIS: The study was undertaken to compare measurement of mitral valve volume in normal subjects and in patients with rheumatic mitral valve stenosis. METHODS: An HP Sonos 2500 echocardiographic system with 5 MHz multiplane transesophageal transducer was used for data acquisition, and TomTec Echoscan computer setup was used to off-line volume computation. Study subjects included 10 normal subjects (mean age 44.8 years) and 36 patients with rheumatic mitral valve stenosis (22 female, 14 male) with an age range of 25 to 69 years (mean age 47 +/- 9.6 years). Mitral valve volumes were compared between the normal subjects and patients with mitral valve stenosis, and further comparison was made between the sinus rhythm (SR) and atrial fibrillation (AF) groups in patients with mitral valve stenosis. In all study subjects, the mitral valve area (MVA) was determined by two-dimensional echocardiography. RESULTS: Quantitative three-dimensional (3-D) echocardiography showed that mitral valve volume was significantly larger in patients with mitral valve stenosis than in normal subjects (9.0 +/- 2.2 and 4.5 +/- 0.7 ml, respectively, p < 0.001). When patients with mitral valve stenosis were divided into the SR and AF groups, mitral valve volume was found to be significantly larger in the AF group than in the SR group (9.76 +/- 2.2 ml. and 7.72 +/- 1.5 ml, respectively, p < 0.01) and patients in the AF group tended to be older (p < 0.05) with larger left atrial diameter (LAD) (p < 0.01). However, MVA between the two groups showed no statistical significance (1.1 +/- 0.43 and 1.0 +/- 0.34 cm2, respectively, p > 0.2). When the study subjects were divided into two groups (< 50 and > or = 50 years) according to age, the comparison of mitral valve volume between these two groups (9.37 +/- 2.18 and 8.56 +/- 2.14 ml, p > 0.2) showed no statistical significance. CONCLUSIONS: Quantitative 3-D echocardiography can be applied for the measurement of mitral valve volume in vivo. Patients with rheumatic mitral valve stenosis with atrial fibrillation have a propensity to have a larger mitral valve volume and are older than the patients with sinus rhythm; however, the age per se does not seem to be a cause for larger mitral valve volume.

Doppler echocardiographic assessment of long-term progression of mitral stenosis in 103 patients: valve area and right heart disease.

OBJECTIVES: The purpose of this study was to determine, in a large referral population, the rate of echocardiographic change in mitral valve area (MVA) without interim intervention, to determine which factors influence progression of narrowing and to examine associated changes in the right side of the heart. BACKGROUND: Little information is currently available on the echocardiographic progression of mitral stenosis, particularly on progressive changes in the right side of the heart and the ability of a previously proposed algorithm to predict progression. METHODS: We studied 103 patients (mean age 61 years; 74% female) with serial two-dimensional and Doppler echocardiography. The average interval between entry and most recent follow-up study was 3.3 +/- 2 years (range 1 to 11). RESULTS: During the follow-up period, MVA decreased at a mean rate of 0.09 cm2/year. In 28 patients there was no decrease, in 40 there was only relatively little change (< 0.1 cm2/year) and in 35 the rate of progression of mitral valve narrowing was more rapid (> or = 0.1 cm2/year). The rate of progression was significantly greater among patients with a larger initial MVA and milder mitral stenosis (0.12 vs. 0.06 vs. 0.03 cm2/year for mild, moderate and severe stenosis, p < 0.01). Although the rate of mitral valve narrowing was a weak function of initial MVA and echocardiographic score by multivariate analysis, no set of individual values or cutoff points of these variables or pressure gradients could predict this rate in individual patients. There was a significant increase in right ventricular diastolic area (17 to 18.7 cm2) and tricuspid regurgitation grade (2 + to 3 +; p < 0.0001 between entry and follow-up studies). Progression in right heart disease occurred even in patients with minimal or no change in MVA. Patients with associated aortic regurgitation had a higher rate of decrease in MVA than did those with trace or no aortic regurgitation (0.19 vs. 0.086 cm2/year, p < 0.05). CONCLUSIONS: The rate of mitral valve narrowing in individual patients is variable and cannot be predicted by initial MVA, mitral valve score or transmitral gradient, alone or in combination. Right heart disease can progress independent of mitral valve narrowing.