Patrick Montant

Evaluation of Anatomic Valve Opening and Leaflet Morphology in Aortic Valve Bioprosthesis by Using Multidetector CT: Comparison with Transthoracic Echocardiography

PURPOSE To prospectively determine whether cardiac-gated multidetector computed tomography (CT) allows visualization of aortic valve leaflets after bioprosthetic aortic valve replacement (AVR), to provide an accurate method for measuring the aortic valve opening, and to provide morphologic and functional information regarding the mechanism underlying poor function of the bioprosthetic valve. MATERIALS AND METHODS The institutional review board approved the study protocol; informed consent was given. Fifty-four patients (27 men; mean age, 75 years + or - 8 [standard deviation]) with bioprosthetic AVR implanted 2 years + or - 3 earlier underwent 64-section CT and transthoracic echocardiography (TTE). Two blinded observers manually planimetered the aortic valve area (AVA) by using a computer workstation on end-systolic short-axis CT images and measured opening angles (OAs) between the bioprosthesis annulus base and the free margin on long-axis images. These measurements were compared with those of the effective orifice area (EOA) of the valve at Doppler continuity-equation TTE by using regression and Bland-Altman methods. Morphology and mobility of leaflets in normally functioning (EOA indexed to body surface area [EOA(i)] > 0.65 cm(2)/m(2)) and dysfunctional (EOA(i)< 0.65 cm(2)/m(2)) AVRs were compared. RESULTS AVA at CT correlated highly to EOA at TTE (r = 0.93, P < .001) but was significantly larger (1.2 cm(2) + or - 0.4 vs 1.1 cm(2) + or - 0.3, P < .001) than EOA at TTE. In dysfunctional bioprostheses (n = 34), CT results showed a variety of morphologic abnormalities, such as leaflet thickening (n = 9), presumed thrombotic material (n = 6), and leaflet calcification (n = 1). Multidetector CT results demonstrated restriction of leaflet motion indicated by lower OA (64 degrees + or - 5 vs 79 degrees + or - 3, P < .0001) in dysfunctional AVRs than in normally functioning AVRs (n = 11). CONCLUSION Sixty-four-section CT can help accurately measure AVA in bioprosthetic AVR compared with EOA at TTE. It can also show morphologic abnormalities and reduced leaflet motion in a dysfunctional bioprosthesis, thereby potentially unraveling the mechanism of dysfunction.

Long-term clinical outcome of mitral valve repair in asymptomatic severe mitral regurgitation,

OBJECTIVE To assess the long-term survival, the incidence of cardiac complications and the factors that predict outcome in asymptomatic patients with severe degenerative mitral regurgitation (MR) undergoing mitral valve repair. METHODS Up to 143 asymptomatic patients (mean age 63+/-12 years) with severe degenerative MR who underwent mitral valve repair between 1990 and 2001 were subsequently followed up for a median of 8 years. The study population was subdivided into three subgroups: patients with left ventricular (LV) dysfunction and/or dilatation (n=18), patients with atrial fibrillation and/or pulmonary hypertension (n=44) and patients without MR-related complications (n=81). RESULTS For the patients, 10-year overall and cardiovascular survival was 82+/-4% and 90+/-3%. At 10 years, patients without preoperative MR-related complications had significantly better overall survival than patients with preoperative LV dysfunction and/or dilatation (89+/-4% vs 57+/-13%, log rank p=0.001). Patients without preoperative MR-related complications also tended to have a better 10-year overall and cardiovascular survival than patients with atrial fibrillation and/or pulmonary hypertension (overall survival of 79+/-8%), although this did not reach statistical significance (log rank p=0.17). Cox regression analysis identified the baseline left ventricular ejection fraction and age as the sole independent predictors of outcome. CONCLUSION Our data indicate that in asymptomatic patients with severe degenerative MR, mitral valve repair is associated with an excellent long-term prognosis. Nonetheless, the presence of preoperative MR-related complications, in particular LV dysfunction and/or dilatation, greatly attenuates the benefits of surgery. This suggests that mitral valve repair should be performed early, before any MR-related complications ensue.

Detection and quantification of myocardial scars by contrast-enhanced 3D echocardiography

Background —Myocardial infarct scars are usually imaged using delayed-enhanced cardiac magnetic resonance (DE-cMR). In this study, we tested the hypothesis that the detection and the quantification of myocardial scars can be evaluated by 3D-Echo. Methods and Results —Fifty patients with a healed myocardial infarction (>3 months) and 10 controls underwent 3D-Echo and DE-cMR within 2 weeks. 3D-Echo images were acquired using different settings, in the presence or absence of contrast. The highest contrast-to-noise ratio was obtained using second harmonic imaging (1.6/3.2 MHz), at an MI of 0.5, in the presence of contrast. Using this modality, the sensitivity and specificity for the 3D-Echo detection of cMR scars on a segmental basis were 78% and 99%, respectively. On a per patient basis, they were of 96% and 90%, respectively. Good correlation and limits of agreement were found between the assessment of scar mass by 3D-Echo and DE-cMR (r=0.93, p<0.001, bias: 1.4±3.6g), and the concordance between both techniques for the assessment of scar transmurality was good. Intraobserver, interobserver and day-to-day reproducibility was comparable between 3D-Echo and DE-cMR for both the detection and the quantification of scars. Conclusions —Contrast-enhanced 3D-Echo is a promising new tool for the detection and the quantification of myocardial infarct scars.Background—Myocardial infarct scars are usually imaged by delayed-enhanced cardiac magnetic resonance (DE-cMR). In this study, we tested the hypothesis that the detection and quantification of myocardial scars can be evaluated by 3D echocardiography (3D-echo). Methods and Results—Fifty patients with a healed myocardial infarction (>3 months) and 10 controls underwent 3D echo and DE-cMR within 2 weeks. 3D-echo images were acquired with different settings, with or without contrast. The highest contrast-to-noise ratio was obtained with second-harmonic imaging (1.6/3.2 MHz), at a mechanical index of 0.5, in the presence of contrast. Using this modality, we calculated the sensitivity and specificity of the 3D-echo detection of cMR scars on a segmental basis to be 78% and 99%, respectively. On a per-patient basis, they were 96% and 90%, respectively. Good correlation and limits of agreement were found between the assessment of scar mass by 3D echo and DE-cMR (r=0.93, P<0.001; bias, 1.4±3.6 g), and the concordance between both techniques for the assessment of scar transmurality was good. Intraobserver, interobserver, and day-to-day reproducibility was comparable between 3D echo and DE-cMR for both the detection and quantification of scars. Conclusions—Contrast-enhanced 3D echo is a promising new tool for the detection and quantification of myocardial infarct scars.

Determination of Infarct Size and Transmurality by Contrast-Enhanced 3D-Echocardiography

Background —Myocardial infarct scars are usually imaged using delayed-enhanced cardiac magnetic resonance (DE-cMR). In this study, we tested the hypothesis that the detection and the quantification of myocardial scars can be evaluated by 3D-Echo. Methods and Results —Fifty patients with a healed myocardial infarction (>3 months) and 10 controls underwent 3D-Echo and DE-cMR within 2 weeks. 3D-Echo images were acquired using different settings, in the presence or absence of contrast. The highest contrast-to-noise ratio was obtained using second harmonic imaging (1.6/3.2 MHz), at an MI of 0.5, in the presence of contrast. Using this modality, the sensitivity and specificity for the 3D-Echo detection of cMR scars on a segmental basis were 78% and 99%, respectively. On a per patient basis, they were of 96% and 90%, respectively. Good correlation and limits of agreement were found between the assessment of scar mass by 3D-Echo and DE-cMR (r=0.93, p<0.001, bias: 1.4±3.6g), and the concordance between both techniques for the assessment of scar transmurality was good. Intraobserver, interobserver and day-to-day reproducibility was comparable between 3D-Echo and DE-cMR for both the detection and the quantification of scars. Conclusions —Contrast-enhanced 3D-Echo is a promising new tool for the detection and the quantification of myocardial infarct scars.Background—Myocardial infarct scars are usually imaged by delayed-enhanced cardiac magnetic resonance (DE-cMR). In this study, we tested the hypothesis that the detection and quantification of myocardial scars can be evaluated by 3D echocardiography (3D-echo). Methods and Results—Fifty patients with a healed myocardial infarction (>3 months) and 10 controls underwent 3D echo and DE-cMR within 2 weeks. 3D-echo images were acquired with different settings, with or without contrast. The highest contrast-to-noise ratio was obtained with second-harmonic imaging (1.6/3.2 MHz), at a mechanical index of 0.5, in the presence of contrast. Using this modality, we calculated the sensitivity and specificity of the 3D-echo detection of cMR scars on a segmental basis to be 78% and 99%, respectively. On a per-patient basis, they were 96% and 90%, respectively. Good correlation and limits of agreement were found between the assessment of scar mass by 3D echo and DE-cMR (r=0.93, P<0.001; bias, 1.4±3.6 g), and the concordance between both techniques for the assessment of scar transmurality was good. Intraobserver, interobserver, and day-to-day reproducibility was comparable between 3D echo and DE-cMR for both the detection and quantification of scars. Conclusions—Contrast-enhanced 3D echo is a promising new tool for the detection and quantification of myocardial infarct scars.

Post-infarct myocardial scar imaging in patients with ICD.

Scar imaging and substrate mapping are recognized as important steps in the post-infarct revascularization strategy. It is also helpful in planning ventricular tachycardia ablation or to better define the patient prognosis. However, delayed contrast enhanced (DE) cardiac magnetic resonance (cMR), the gold standard …

Chronic Mitral Regurgitation

The mitral valve is a complex, bi-leaflet structure that separates the left atrium (LA) and the left ventricle (LV). It consists of two leaflets, a fibrous annulus, chordae tendinae, two papillary muscles, and their left ventricular attachments (Fig. 3.1).