Two-dimensional echocardiographic evaluation of mitral valve calcification. Sensitivity and specificity

Association of aortic valve calcium detected by electron beam computed tomography with echocardiographic aortic valve disease and with calcium deposits in the coronary arteries and thoracic aorta

We conducted electron beam computed tomographic (EBCT) testing in a representative sample of 327 Framingham Heart Study subjects without clinical cardiovascular disease. EBCT was compared with 2-dimensional echocardiography for the detection of degenerative aortic valve (AV) disease. We determined the association between EBCT measures of AV calcium and calcium deposits in the coronary arteries and thoracic aorta. Of 327 subjects (mean age 60 +/- 9 years; 51% men), 14% had EBCT AV calcium (median Agatston score 0, range 0 to 1,592). The prevalence of AV calcium increased predictably across decades of age. Compared with echocardiography, the sensitivity and specificity of EBCT for the detection of degenerative AV disease were 24% and 94%, respectively. In unadjusted logistic regression models, the prevalence of EBCT AV calcium increased across tertiles of coronary artery calcium (for trend across tertiles, odds ratio [OR] 2.2, 95% confidence interval [CI] 1.4 to 3.5) and thoracic aorta calcium (for trend OR 2.8, 95% CI 1.7 to 4.4). After adjustment for age and gender, the associations of AV calcium with coronary calcium and thoracic aorta calcium were attenuated and no longer statistically significant. Thus, compared with echocardiography, EBCT was specific but insensitive for the detection of degenerative AV disease. EBCT AV calcium was associated with calcium deposits in the coronary arteries and the thoracic aorta, but these associations were confounded by age and risk factors.

Accurate assessment of mitral valve area in patients with mitral stenosis by three-dimensional echocardiography

The accuracy of measurements of mitral valve orifice area (MVA) from three-dimensional echocardiographic (3DE) image data sets obtained by a transthoracic or transesophageal rotational imaging probe was studied in 15 patients with native mitral stenosis. The smallest MVA was identified from a set of eight parallel short-axis cut planes of the mitral valve between the anulus and the tips of leaflets (paraplane echocardiography) and measured by planimetry. In addition, MVA was measured from the two-dimensional short-axis view (2DE). Values of MVA measured by 3DE and 2DE were compared with those calculated from Doppler pressure half-time (PHT) as a gold standard. Observer variabilities were studied for 3DE. MVA measured from PHT ranged between 0.55 and 3.19 cm2 (mean +/- SD 1.57 +/- 0.73 cm2), from 3DE between 0.83 and 3.23 cm2 (mean +/- SD 1.55 +/- 0.67 cm2), and from 2DE between 1.27 and 4.08 cm2 (mean +/- SD 1.9 +/- 0.7 cm2). The variability of intraobserver and interobserver measurements for 3DE measurements was not significantly different (p = 0.79 and p = 0.68, respectively); for interobserver variability, standard error of the estimate = 0.25. There was excellent correlation, close limits of agreement (mean difference +/- 2 SD), and nonsignificant differences between 3DE and PHT for MVA measurements (r = 0.98 [0.02 +/- 0.3] and p = 0.6), respectively. There was moderate correlation, wider limits of agreement, and significant difference between 2DE and PHT for MVA measurements (r = 0.89 [0.32 +/- 0.66] and p = 0.002), respectively. This may be related to the difficulties in visualization of the smallest orifice in precordial short-axis views. This study suggests that three-dimensional image data sets, by providing the possibility of "computer slicing" to generate equidistant parallel cross sections of the mitral valve independently from physically dictated ultrasonic windows, allow accurate and reproducible measurement of the MVA.

Comparison of transthoracic and transesophageal echocardiography with surgical findings in mitral regurgitation. The ESMIR Research Group

This prospective study was conducted to ascertain whether echocardiographic evaluation could provide more insight into the genesis of mitral regurgitation (MR) before surgery. All patients underwent preoperative transthoracic and transesophageal echocardiography. Nine centers participated in the ESMIR (Echocardiographic Selection of patients for MItral valve Reconstruction) study and 350 patients were included. Compared with surgical findings, the percentage of functional abnormalities correctly predicted by both echo modalities was highest in patients with increased leaflet mobility (83% for transthoracic and 86% transesophageal echocardiography). In contrast, in normal leaflet mobility, the prediction was better by transthoracic than by transesophageal echocardiography (75% vs 64%). In patients with restricted leaflet mobility, the predictive value of both techniques was similar. The diagnostic yield of anatomic abnormalities of both echo techniques was similar, except for chordal rupture; a sensitivity by transesophageal echocardiography of 79% and by transthoracic echocardiography of 57% (p < 0.001). In general, the sensitivity of each echo technique for detecting anatomic abnormalities was <70%, except for annular dilatation, leaflet thickening, and chordal rupture. At surgery, the prevailing functional condition was increased leaflet mobility (42%). The conclusion is that both echo techniques provide adequate information regarding the functional condition of the mitral valve apparatus, not withstanding limitations in assessing anatomic details. Transthoracic echocardiography appears to be sufficient for preoperative evaluation of MR.

In vivo identification of mitral valve fibrosis and calcium by real-time quantitative ultrasonic analysis

Conventional echocardiography provides fundamental information about mitral valve morphology and function but has a relatively low specificity in evaluating valve calcific deposits, which is critical information for the preoperative decision to perform commisurotomy or replacement. In vitro radiofrequency ultrasonic quantitative analysis of the mitral valve has been demonstrated to be a reliable tool in identifying normal, fibrotic and calcific valves. This study evaluates quantitative ultrasound characterization of the mitral valve in vivo. Thirty-three patients, scheduled to undergo mitral valve replacement, and 20 normal subjects (10 young and 10 older control subjects) were studied with a 2.25-MHz transducer. Radiofrequency signal was analyzed by a microprocessor system (used with an M-mode commercially available echocardiograph) for on-line evaluation of ultrasonic backscatter with 8 bits of amplitude resolution, 40-MHz sampling rate and a 1-microsecond acquisition gate. The integrated value of the rectified radiofrequency signal amplitude was deemed the integrated backscatter index. The highest value recorded with the ultrasonic analysis from each valve was taken as representative and expressed as the percent value with respect to the pericardial integrated backscatter index value of that subject. The 33 excised mitral valves underwent histologic examination. Four groups were identified: young controls (group I, n = 10); older controls age-matched with patients (group II, n = 10); patients with fibrotic mitral valves (group III, n = 13); and patients with calcific mitral valves (group IV, n = 20).(ABSTRACT TRUNCATED AT 250 WORDS)

Influence of mitral valve morphology on double-balloon catheter balloon valvuloplasty in patients with mitral stenosis. Analysis of factors predicting immediate and 3-month results

To determine if mitral valve morphology influences the results of double-balloon catheter balloon valvuloplasty (CBV) for mitral stenosis, two-dimensional echocardiography was performed in 33 patients before CBV. The two-dimensional echocardiographic features of leaflet motion, leaflet thickness, subvalvular disease, and commissural calcium and 14 pre-CBV clinical and hemodynamic variables were then correlated to the immediately post-CBV mitral valve area (MVA). At 3 months after CBV, the two-dimensional echocardiographic features of patients with a 25% or greater decrease in MVA were analyzed to determine whether mitral valve morphology had influenced early results. Leaflet motion had a significant relation with the immediately post-CBV MVA (r = 0.67, y = 4.5x + 0.29, and SEE = 0.45). Leaflet thickness had a weak and negative relation (r = -0.48, y = -0.17x + 2.6, and SEE = 0.53) with the immediately post-CBV MVA. Subvalvular disease and commissural calcium had no significant relation to the immediately post-CBV MVA. When leaflet motion and leaflet thickness were considered as grades of mild, moderate, and severe and assigned a score of 0-2, patients with more severe disease (total score, 3 or 4) had a significant lower MVA immediately after CBV (1.4 +/- 0.4 cm2) than patients with moderate disease (score, 1-2; MVA, 2.0 +/- 0.5 cm2; p less than 0.05) or mild disease (score, 0; MVA, 2.6 +/- 0.6 cm2; p less than 0.05). In 96% of patients with a total score of 0-2, the immediately post-CBV MVA was more than 1.4 cm2, whereas only 29% of patients with a total score of 3-4 had an immediately post-CBV MVA of more than 1.4 cm2. Analysis of all two-dimensional echocardiographic features showed that leaflet motion score had the strongest influence on the post-CBV MVA (p less than 0.001). When all two-dimensional echocardiographic, clinical, and hemodynamic variables were included, leaflet motion, effective balloon dilating area, and cardiac output were the strongest predictors of the immediate post-CB MVA.(ABSTRACT TRUNCATED AT 400 WORDS)