Publications (35)219.27 Total impact
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Article: Prognostic value of myocardial viability by delayed-enhanced magnetic resonance in patients with coronary artery disease and low ejection fraction: impact of revascularization therapy.
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ABSTRACT: The purpose of this study was to evaluate the impact of myocardial viability assessment by delayed-enhanced cardiac magnetic resonance (DE-CMR) and of revascularization therapy on survival in patients with coronary artery disease (CAD) and low ejection fraction (EF). Prior studies have shown that DE-CMR predicts recovery of left ventricular (LV) dysfunction after revascularization. The authors prospectively evaluated survival of 144 consecutive patients (130 males, age 65 ± 11 years) with CAD and LV dysfunction (EF: 24 ± 7%) undergoing DE-CMR. Eighty-six patients underwent complete revascularization of dysfunctional myocardium (79 coronary artery bypass grafting, 7 percutaneous coronary intervention), whereas 58 patients remained under medical treatment. Over the 3-year median follow-up, 49 patients died. Three-year survival was significantly worse in medically treated patients with dysfunctional viable than with nonviable myocardium (48% vs. 77% survival, p = 0.02). By contrast, in revascularized patients, survival was similar whether myocardium was viable or not (88% and 71% survival, respectively, p = NS). Hazard of death of viable myocardium remaining under medical treatment versus complete revascularization was 4.56 (95% confidence interval [CI]: 1.93 to 10.8). Cox multivariate analysis indicated that interaction of revascularization and viability provided significant additional value (chi-square test = 13.1, p = 0.004) to baseline predictors of survival (New York Heart Association functional class, wall motion score, and peripheral artery disease). More importantly, in 43 pairs of propensity score-matched patients, hazard of death (hazard ratio: 2.5 [95% CI: 1.1 to 6.1], p = 0.02) remained significantly higher for medically treated patients rather than for those with fully revascularized viable myocardium. Without revascularization, presence of dysfunctional viable myocardium by DE-CMR is an independent predictor of mortality in patients with ischemic LV dysfunction. This observation may be useful for pre-operative selection of patients for revascularization.Journal of the American College of Cardiology 02/2012; 59(9):825-35. · 14.16 Impact Factor -
Article: Echinococcosis of the heart and ascending aorta.
Circulation 01/2012; 125(1):185-7. · 14.74 Impact Factor -
Article: Imaging the vulnerable plaque.
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ABSTRACT: Cardiovascular diseases are still the primary causes of mortality in the United States and in Western Europe. Arterial thrombosis is triggered by a ruptured atherosclerotic plaque and precipitates an acute vascular event, which is responsible for the high mortality rate. These rupture-prone plaques are called "vulnerable plaques." During the past decades, much effort has been put toward accurately detecting the presence of vulnerable plaques with different imaging techniques. In this review, we provide an overview of the currently available invasive and noninvasive imaging modalities used to detect vulnerable plaques. We will discuss the upcoming challenges in translating these techniques into clinical practice and in assigning them their exact place in the decision-making process.Journal of the American College of Cardiology 05/2011; 57(20):1961-79. · 14.16 Impact Factor -
Article: Detection and quantification of myocardial scars by contrast-enhanced 3D echocardiography.
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ABSTRACT: 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). 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. Contrast-enhanced 3D echo is a promising new tool for the detection and quantification of myocardial infarct scars.Circulation Cardiovascular Imaging 07/2010; 3(4):415-23. · 5.94 Impact Factor -
Article: Mechanisms of recurrent aortic regurgitation after aortic valve repair: predictive value of intraoperative transesophageal echocardiography.
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ABSTRACT: The aim of the present study was to examine the intraoperative echocardiographic features associated with recurrent severe aortic regurgitation (AR) after an aortic valve repair surgery. Surgical valve repair for AR has significant advantages over valve replacement, but little is known about the predictors and mechanisms of its failure. We blindly reviewed all clinical, pre-operative, intraoperative, and follow-up transesophageal echocardiographic data of 186 consecutive patients who underwent valve repair for AR during a 10-year period and in whom intraoperative and follow-up echo data were available. After a median follow-up duration of 18 months, 41 patients had recurrent 3+ AR, 23 patients presented with residual 1+ to 2+ AR, and 122 had no or trivial AR. In patients with recurrent 3+ AR, the cause of recurrent AR was the rupture of a pericardial patch in 3 patients, a residual cusp prolapse in 26 patients, a restrictive cusp motion in 9 patients, an aortic dissection in 2 patients, and an infective endocarditis in 1 patient. Pre-operatively, all 3 groups were similar for aortic root dimensions and prevalence of bicuspid valve (overall 37%). Patients with recurrent AR were more likely to display Marfan syndrome or type 3 dysfunction pre-operatively. At the opposite end, patients with continent AR repair at follow-up were more likely to have type 2 dysfunction pre-operatively. After cardiopulmonary bypass, a shorter coaptation length, the degree of cusp billowing, a lower level of coaptation (relative to the annulus), a larger diameter of the aortic annulus and the sino-tubular junction, the presence of a residual AR, and the width of its vena contracta were associated with the presence of AR at follow-up. Multivariate Cox analysis identified a shorter coaptation length (odds ratio [OR]: 0.8, p = 0.05), a coaptation occurring below the level of the aortic annulus (OR: 7.9, p < 0.01), a larger aortic annulus (OR: 1.2, p = 0.01), and residual aortic regurgitation (OR: 5.3, p = 0.01) as risk factors of repair failure. Our results demonstrate that intraoperative transesophageal echocardiography can be used to identify patients undergoing AR repair who are at increased risk for late repair failure.JACC. Cardiovascular imaging 09/2009; 2(8):931-9. · 14.29 Impact Factor -
Article: Early hazards of mitral ring annuloplasty in patients with moderate to severe ischemic mitral regurgitation undergoing coronary revascularization: the importance of preoperative myocardial viability.
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ABSTRACT: The impact of adding mitral ring annuloplasty (MRA) to coronary bypass grafting (CABG) in patients with ischemic mitral regurgitation (iMR) is unclear. The study aim was to compare the 30-day and four-year survival of patients with moderate to severe iMR undergoing CABG or CABG+MRA, and to investigate the role of contractile reserve (CR) in the prognostic response to MRA. A total of 76 coronary patients (61 men, 15 women; mean age 62 +/- 9 years) with poor left ventricular ejection fraction (LVEF) of 33 +/- 11% and grade > or =2 iMR underwent low-dose dobutamine echocardiography to identify their CR before CABG. The survival of 34 patients undergoing CABG+MRA was compared to that of 42 patients who underwent CABG alone. The groups were further substratified according to their preoperative CR. During follow up, 24 patients died from cardiac causes, and two others required heart transplantation. At one year, the residual iMR and NYHA functional class were lower in patients undergoing MRA than in those that did not. The 30-day and four-year survivals were lower in patients undergoing MRA in the absence of CR than in the other patients (71 +/- 11% versus 95 +/- 3% at 30 days, p = 0.002; 35 +/- 11% versus 69 +/- 6% at four years, p = 0.008). Cox's proportional hazard analysis identified CR (HR = 0.14, 95% CI 0.05-0.38, p < 0.001), MRA (HR = 3.54, 95% CI 1.48-8.50, p = 0.004), additive EuroSCORE (HR = 1.29, 95% CI 1.08-1.55, p = 0.006) and LVEF (HR = 0.93, 95% CI 0.59-0.98, p = 0.001) as independent predictors of long-term outcome in this population. In patients with moderate to severe iMR, survival after CABG is mainly influenced by the presence of CR. By contrast, adding MRA to CABG does not affect long-term survival, except in patients without CR, in whom it increases early mortality.The Journal of heart valve disease 01/2009; 18(1):35-43. · 0.81 Impact Factor -
Chapter: Principles of Myocardial Viability Implications for Echocardiography
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ABSTRACT: As a result of improved anesthetic, surgical, and myocardial protection techniques, the surgical risks of performing coronary artery bypass graft (CABG) in these patients have decreased significantly between 11 and 16%, to less than 6%. Myocardial revascularization has subsequently become a valid treatment option in selected patients with observed survival benefits compared to medical therapy, and in some cases, improvement in symptoms and functional status.12/2008: pages 351-365; -
Article: Chronic ischemic left ventricular dysfunction: from pathophysiology to imaging and its integration into clinical practice.
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ABSTRACT: Chronic ischemic left ventricular dysfunction is present in a number of clinical syndromes in which myocardial revascularization results in an improvement of left ventricular function, patients' functional class, and their survival. Early diagnosis of and treatment of viability is essential. Coronary arteriography is of limited value in diagnosis of viability. Noninvasive testing is essential for diagnosis, which can be matched to the pathophysiologic changes that occur in hibernating myocardium. However, no single test has a perfect, or near perfect, sensitivity and specificity, and thus, a combination of tests are usually needed. Algorithms are developed to integrate these tests in clinical decision making.JACC. Cardiovascular imaging 08/2008; 1(4):536-55. · 14.29 Impact Factor -
Article: Is postsystolic shortening a marker of viability in chronic left ventricular ischemic dysfunction? Comparison with late enhancement contrast magnetic resonance imaging.
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ABSTRACT: During acute myocardial ischemia, myocardial postsystolic shortening (PSS) is considered as a sign of viability. In chronic left ventricular (LV) ischemic dysfunction, the value of PSS is less well established. In this study, PSS was compared with transmural extent of necrosis and contractile reserve in patients with chronic LV ischemic dysfunction. A total of 25 patients (20 men, mean age: 63 +/- 8 years) with LV dysfunction (mean ejection fraction: 32 +/- 10%, range: 14%-47%) and stable coronary artery disease underwent rest color Doppler myocardial imaging, low-dose dobutamine echocardiography, and late enhancement gadolinium-magnetic resonance imaging. Strain (epsilon) curves were computed in 16 segments from color Doppler myocardial imaging sequences and were compared with transmural extent of necrosis and with contractile reserve. End-systolic epsilon was defined as epsilon value at aortic valve closure, peak epsilon (epsilon-peak) as maximal epsilon value during cardiac cycle, and time to epsilon-peak as time interval between aortic valve closure and epsilon-peak. PSS was considered when epsilon-peak occurred after aortic valve closure. Of 348 analyzable segments, 212 (61%) were graded as abnormal. In dysfunctional segments, PSS was more prevalent in transmural than in nontransmural infarcted segments (96% vs 50%, P < .001) and time to epsilon-peak was correlated to transmural extent of necrosis (r = 0.69, P < .0001). In nontransmurally infarcted segments, prevalence of PSS was similar in segments with or without contractile reserve (37% vs 45%, respectively). In chronic LV dysfunction, PSS is not a specific marker of viability. These results suggest strongly that delayed myocardial shortening may be associated to scarred segments.Journal of the American Society of Echocardiography: official publication of the American Society of Echocardiography 05/2008; 21(5):452-7. · 2.98 Impact Factor -
Article: Successful repair of a quadricuspid aortic valve illustrated by transoesophageal echocardiography, 64-slice multidetector computed tomography, and cardiac magnetic resonance.
European Heart Journal 12/2007; 28(22):2769. · 10.48 Impact Factor -
Article: Planimetric and continuity equation assessment of aortic valve area: Head to head comparison between cardiac magnetic resonance and echocardiography.
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ABSTRACT: To compare the accuracy of planimetric and continuity equation measurements of aortic valve area (AVA) by cardiac MR (cMR) to each other and against transthoracic (TTE) and transesophageal (TEE) echocardiography. A total of 31 patients (21 men, mean age = 67 +/- 13 years) with aortic stenosis (AS) and 16 controls (12 men, mean age = 57 +/- 14 years) underwent measurement of AVA by planimetric and continuity equation cMR. Measurements were compared to TEE planimetry and continuity equation TTE. AVA by continuity equation cMR correlated highly to continuity equation TTE (r = 0.98) and was not significantly different (1.8 +/- 1.3 cm2 vs. 1.8 +/- 1.4 cm2, P = 0.62). Similarly, AVA by cMR planimetry was not statistically different from TEE planimetry (2.1 +/- 1.7 cm2 vs. 2.1 +/- 1.6 cm2, P = 0.34) and correlated highly (r = 0.98). Yet planimetric measurements of AVA by cMR and TEE were significantly higher than AVA by continuity equation cMR (P < 0.001 and P < 0.001, respectively) and TTE (P < 0.001 and P < 0.001, respectively). Both planimetry and continuity equation-based measurements of AVA by cMR are equally accurate. However, similar to TEE, cMR AVA is larger by planimetry than by continuity equation. This is consistent with the contention that the anatomical maximum opening of a stenotic aortic valve is larger than the size of the functional vena contracta.Journal of Magnetic Resonance Imaging 12/2007; 26(6):1436-43. · 2.70 Impact Factor -
Article: Aortic valve area assessment: multidetector CT compared with cine MR imaging and transthoracic and transesophageal echocardiography.
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ABSTRACT: To prospectively compare the accuracy of multidetector computed tomographic (CT) measurements of the aortic valve area (AVA) with transesophageal echocardiography (TEE) and cine magnetic resonance (MR) measurements of this area for preoperative examination of patients undergoing cardiac surgery, with transthoracic echocardiography (TTE) as the reference standard. After giving informed consent for the institutional review board-approved study protocol, 48 patients (33 men, 15 women; mean age, 62 years+/-13 [standard deviation]) with (n=27) or without (n=21) aortic stenosis underwent multidetector CT, cine MR, TTE, and TEE before undergoing cardiac surgery. AVAs derived with manual planimetry by using cine short-axis multidetector CT, MR, and TEE images obtained through the aortic valve were compared among each other and with AVAs measured by using continuity equation TTE at regression and Bland-Altman analyses. The diagnostic accuracy of multidetector CT for detection of aortic stenosis was compared with that of TTE by using kappa statistics and receiver operating characteristic curves. Multidetector CT-derived AVA correlated highly with MR-derived (r=0.98, P<.001), TEE-derived (r=0.98, P<.001), and TTE-derived (r=0.96, P<.001) AVA. Multidetector CT planimetry AVAs (mean AVA+/-standard deviation, 2.5 cm2+/-1.7) were not significantly different from MR planimetry (2.4 cm2+/-1.8, P>.99) or TEE planimetery (2.5 cm2+/-1.7, P=.21) AVAs, but they were significantly larger than TTE-derived AVAs (2.0 cm2+/-1.5, P<.001). With TTE as the reference standard, multidetector CT correctly (kappa=0.88, P<.001) depicted all 21 normal, six of eight mildly stenotic (AVA>or=1.2 cm2 and <2.0 cm2), seven of eight moderately stenotic (AVA>or= 0.8 cm2 and <1.2 cm2), and 10 of 11 severely stenotic (AVA<0.8 cm2) valves. It also correctly depicted all 14 bicuspid valves identified with TEE, eight of which were missed with TTE. Multidetector CT enables accurate noninvasive assessment of the AVA.Radiology 10/2007; 244(3):745-54. · 5.73 Impact Factor -
Article: Functional anatomy of aortic regurgitation: accuracy, prediction of surgical repairability, and outcome implications of transesophageal echocardiography.
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ABSTRACT: For patients with aortic regurgitation (AR), aortic valve sparing or repair surgery is an attractive alternative to valve replacement. In this setting, accurate preoperative delineation of aortic valve pathology and potential repairability is of paramount importance. The aim of the present study was to assess the diagnostic value of preoperative transesophageal echocardiography (TEE) in defining the mechanisms of AR, as identified by surgical inspection, and in predicting repairability, by using the final surgical approach as reference. One hundred and sixty-three consecutive patients (117 males, mean age: 58+/-14 years) undergoing AR surgery were included. Mechanisms of AR were categorized by TEE and surgical inspection as follows: type 1, aortic dilatation; type 2, cusp prolapse; and type 3, restrictive cusp motion or endocarditis. At surgery, mechanisms of AR were type 1 in 41 patients, type 2 in 62, and type 3 in 60. Agreement between TEE and surgical inspection was 93% (kappa=0.90). Valve sparing or repair was performed in 125 patients and valve replacement in 38 patients. TEE correctly predicted the final surgical approach in 108/125 (86%) patients undergoing repair and in 35/38 (93%) patients undergoing replacement. The gross anatomic classification of AR lesions by TEE was determinant of valve repairability and postoperative outcome (4-year freedom from > grade 2 AR, reoperation, or death, P=0.04). TEE provides a highly accurate anatomic assessment of all types of AR lesions. In addition, the functional anatomy of AR defined by TEE is strongly and independently predictive of valve repairability and postoperative outcome.Circulation 09/2007; 116(11 Suppl):I264-9. · 14.74 Impact Factor -
Article: Release of cardiac bio-markers during high mechanical index contrast-enhanced echocardiography in humans.
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ABSTRACT: Recent experimental data have shown that the combined exposure of rodent hearts to high acoustic pressure and ultrasound contrast agents can induce vascular injury and cell damage. The aim of the present work was to test whether similar effects can be observed in humans. Twenty patients underwent simultaneous arterial and coronary sinus blood sampling during contrast-enhanced echocardiography using Perfluorocarbon-enhanced Sonicated Dextrose Albumin. Control subjects were compared to groups of patients exposed to either high mechanical index (MI = 1.5) triggered second harmonic (1.3-2.6 MHz) imaging or low mechanical index (MI = 0.2) real-time power modulation imaging for 15 min. No significant changes arterio-venous differences in lactate, total creatine kinase (CK) and myoglobin occurred over time in the three groups. Similarly, the arterio-venous difference in CK-MB and troponin I remained stable over time in control and low-MI patients. By contrast, these two parameters progressively increased over time in the high-MI group (P < 0.05 vs. baseline and vs. controls). Our data suggest that high-MI contrast-enhanced echocardiography can cause subclinical release of cardiac bio-markers in humans, while low-MI real-time imaging appears to be safer.European Heart Journal 05/2007; 28(10):1236-41. · 10.48 Impact Factor -
Article: Diagnostic accuracy of 16-slice multidetector-row CT for detection of in-stent restenosis vs detection of stenosis in nonstented coronary arteries.
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ABSTRACT: The purpose of this study was to assess the diagnostic accuracy of 16-slice multidetector-row computed tomography (MDCT) for detecting in-stent restenosis. Fifty patients with 69 previously implanted coronary stents underwent 16-slice MDCT before quantitative coronary angiography (QCA). Diagnostic accuracy of MDCT for detection of in-stent restenosis defined as >50% lumen diameter stenosis (DS) in stented and nonstented coronary segments >1.5-mm diameter was computed using QCA as reference. According to QCA, 18/69 (25%) stented segments had restenosis. In addition, 33/518 (6.4%) nonstented segments had >50% DS. In-stent restenosis was correctly identified on MDCT images in 12/18 stents, and absence of restenosis was correctly identified in 50/51 stents. Stenosis in native coronary arteries was correctly identified in 22/33 segments and correctly excluded in 482/485 segments. Thus, sensitivity (67% vs 67% p=1.0), specificity (98% vs 99%, p=0.96) and overall diagnostic accuracy (90% vs 97%, p=0.68) was similarly high for detecting in-stent restenosis as for detecting stenosis in nonstented coronary segments. MDCT has similarly high diagnostic accuracy for detecting in-stent restenosis as for detecting coronary artery disease in nonstented segments. This suggests that MDCT could be clinically useful for identification of restenosis in patients after coronary stenting.European Radiology 01/2007; 17(1):87-96. · 3.22 Impact Factor -
Article: Accurate estimation of global and regional cardiac function by retrospectively gated multidetector row computed tomography: comparison with cine magnetic resonance imaging.
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ABSTRACT: Retrospective reconstruction of ECG-gated images at different parts of the cardiac cycle allows the assessment of cardiac function by multi-detector row CT (MDCT) at the time of non-invasive coronary imaging. We compared the accuracy of such measurements by MDCT to cine magnetic resonance (MR). Forty patients underwent the assessment of global and regional cardiac function by 16-slice MDCT and cine MR. Left ventricular (LV) end-diastolic and end-systolic volumes estimated by MDCT (134+/-51 and 67+/-56 ml) were similar to those by MR (137+/-57 and 70+/-60 ml, respectively; both P=NS) and strongly correlated (r=0.92 and r=0.95, respectively; both P<0.001). Consequently, LV ejection fractions by MDCT and MR were also similar (55+/-21 vs. 56+/-21%; P=NS) and highly correlated (r=0.95; P<0.001). Regional end-diastolic and end-systolic wall thicknesses by MDCT were highly correlated (r=0.84 and r=0.92, respectively; both P<0.001), but significantly lower than by MR (8.3+/-1.8 vs. 8.8+/-1.9 mm and 12.7+/-3.4 vs. 13.3+/-3.5 mm, respectively; both P<0.001). Values of regional wall thickening by MDCT and MR were similar (54+/-30 vs. 51+/-31%; P=NS) and also correlated well (r=0.91; P<0.001). Retrospectively gated MDCT can accurately estimate LV volumes, EF and regional LV wall thickening compared to cine MR.European Radiology 07/2006; 16(7):1424-33. · 3.22 Impact Factor -
Article: Accurate estimation of global and regional cardiac function by retrospectively gated multidetector row computed tomography
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ABSTRACT: Retrospective reconstruction of ECG-gated images at different parts of the cardiac cycle allows the assessment of cardiac function by multi-detector row CT (MDCT) at the time of non-invasive coronary imaging. We compared the accuracy of such measurements by MDCT to cine magnetic resonance (MR). Forty patients underwent the assessment of global and regional cardiac function by 16-slice MDCT and cine MR. Left ventricular (LV) end-diastolic and end-systolic volumes estimated by MDCT (134±51 and 67±56ml) were similar to those by MR (137±57 and 70±60ml, respectively; both P=NS) and strongly correlated (r=0.92 and r=0.95, respectively; both P<0.001). Consequently, LV ejection fractions by MDCT and MR were also similar (55±21 vs. 56±21%; P=NS) and highly correlated (r=0.95; P<0.001). Regional end-diastolic and end-systolic wall thicknesses by MDCT were highly correlated (r=0.84 and r=0.92, respectively; both P<0.001), but significantly lower than by MR (8.3±1.8 vs. 8.8±1.9mm and 12.7±3.4 vs. 13.3±3.5mm, respectively; both P<0.001). Values of regional wall thickening by MDCT and MR were similar (54±30 vs. 51±31%; P=NS) and also correlated well (r=0.91; P<0.001). Retrospectively gated MDCT can accurately estimate LV volumes, EF and regional LV wall thickening compared to cine MR.European Radiology 06/2006; 16(7):1424-1433. · 3.22 Impact Factor -
Article: Myocardial delivery of colloid nanoparticles using ultrasound-targeted microbubble destruction.
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ABSTRACT: Ultrasound (US)-targeted microbubble destruction (UTMD) is a promising method for delivering genetic material to the heart. The aim of this study was: (i) to test whether colloid nanoparticles can be delivered to the rat myocardium using UTMD; and (ii) to determine whether tissue damage and contractile dysfunction occurs in hearts exposed to UTMD in vivo. Hearts from anaesthetized rats were exposed to perfluorocarbon-enhanced sonicated dextrose albumin (PESDA) (at two different microbubble concentrations) and US at peak pressures of 0.6, 1.2, or 1.8 MPa for 1, 3, or 9 min. During US, pairs of 30 and 100 nm fluorescent nanospheres were infused intravenously. Left ventricular function was assessed before and immediately after US, as well as at 24 h and 7 days. At the end of the experiments, the number of ruptured microvessels and the amount of nanospheres deposited were quantified. Rats exposed to PESDA alone or US alone showed no functional abnormalities, no capillary ruptures, and no nanosphere delivery. In contrast, rats exposed to both PESDA and US exhibited microvascular ruptures and nanosphere deposits. They also showed transient contractile dysfunction and premature ventricular contractions. All these changes were time-, US peak pressure-, and PESDA concentration-dependent. UTMD allows colloid nanoparticles to be delivered to the rat myocardium through microvessel rupture sites. The efficacy of delivery depends on the peak pressure applied, the duration of US exposure, and contrast concentration. UTMD also causes time- and peak pressure-dependent contractile dysfunction, and tissue alterations that are spontaneously reversible over time.European Heart Journal 02/2006; 27(2):237-45. · 10.48 Impact Factor -
Article: Characterization of acute and chronic myocardial infarcts by multidetector computed tomography: comparison with contrast-enhanced magnetic resonance.
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ABSTRACT: We evaluated whether contrast-enhanced multidetector computed tomography (CE-MDCT) might characterize myocardial infarct (MI) with patterns similar to those obtained by contrast-enhanced magnetic resonance (CE-MR) and studied the underlying mechanisms. In vivo infarct characterization by CE-MDCT was shown to be feasible between 4 and 20 minutes after contrast injection in 7 pigs with MI. Subsequently, in 16 patients with acute MI and 21 patients with chronic MI, contrast patterns by CE-MDCT were related to CE-MR. Eighteen patients had hypoenhanced regions on early CE-MDCT images at the time of coronary imaging, and 34 patients had hyperenhanced regions on images acquired 10 minutes later. On a segmental basis, there was moderately good concordance of early hypoenhanced regions (92%, kappa=0.54, P<0.001) and late hyperenhanced regions (82%, kappa=0.61, P<0.001) between CE-MDCT and CE-MR. Absolute sizes of early hypoenhanced (6+/-16 versus 7+/-16 g, P=0.25) and late hyperenhanced (36+/-34 versus 31+/-40 g, P=0.14) regions were similar on CE-MDCT and CE-MR and were highly correlated (r=0.93, P<0.001 and r=0.89, P<0.001 respectively). In 8 retrogradely perfused infarcted rabbit hearts, contrast kinetics of iomeprol were similar to gadodiamide, ie, slow wash in (8.7+/-6.7 versus 1.2+/-0.3 minutes, P<0.001) in infarct core and slow washout (20+/-12 versus 2.5+/-0.5 minutes, P<0.001) in both infarct core and rim compared with the remote region. Because iodated contrast agents have similar kinetics in infarcted and noninfarcted myocardium as gadolinium DPTA, CE-MDCT can characterize acute and chronic MI with contrast patterns similar to CE-MR. CE-MDCT may thus provide important information on infarct size and viability at the time of noninvasive coronary imaging.Circulation 02/2006; 113(6):823-33. · 14.74 Impact Factor -
Article: Coronary artery stenosis: direct comparison of four-section multi-detector row CT and 3D navigator MR imaging for detection--initial results.
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ABSTRACT: To prospectively compare the diagnostic accuracy of multi-detector row computed tomography (CT) and of three-dimensional (3D) navigator magnetic resonance (MR) imaging in patients referred for conventional coronary angiography for detection of coronary artery stenosis. All patients gave written informed consent for the study, which was approved by the local ethics committee. Twenty-seven patients underwent multi-detector row CT and 3D navigator free-breathing MR imaging a mean of 5 days before undergoing invasive coronary angiography. The acquired multi-detector row CT and MR images were graded for the presence of greater than 50% stenosis in vessels larger than 1.5 mm in diameter. The diagnostic accuracies of the two examinations were compared with that of quantitative coronary angiography (QCA) by using the McNemar test. Owing to claustrophobia, MR images were not acquired in one patient; thus, 26 patients were included for analysis. According to QCA findings, 21 of the 26 patients had significant coronary artery disease and 58 (20%) of a total of 294 coronary artery segments larger than 1.5 mm in diameter had significant (>50%) stenosis. Multi-detector row CT had significantly higher sensitivity (46 [79%] of 58 segments) than MR imaging (36 [62%] segments, P < .05) for detection of segments with significant stenosis. Conversely, MR imaging had significantly higher specificity (198 [84%] of 236 segments) than did CT (168 [71%] segments, P < .001) for exclusion of segmental coronary artery stenosis. Both examinations had high negative predictive value for exclusion of segmental stenosis: 93% (168 of 180 segments) for CT and 90% (198 of 220 segments) for MR imaging. The overall diagnostic accuracy of MR imaging (80% [234 of 294 segments]) was significantly higher than that of CT (73% [214 segments], P < .05). MR imaging had significantly higher diagnostic accuracy than multi-detector row CT in the evaluation of coronary artery stenosis. Both techniques have high negative predictive value, making them particularly useful for ruling out coronary artery disease in symptomatic patients.Radiology 01/2005; 234(1):98-108. · 5.73 Impact Factor
Top co-authors
Top Journals
- The American Journal of Cardiology (3)
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Institutions
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1999–2012
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Université Catholique de Louvain
- • Institute of Experimental and Clinical Research (IREC)
- • School of Medicine
Louvain-la-Neuve, WAL, Belgium
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2002–2009
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Cliniques Universitaires Saint-Luc
Brussels, BRU, Belgium -
University Hospital Brussels
Brussels, BRU, Belgium
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2008
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University of Southern California
- Division of Cardiovascular Medicine
Los Angeles, CA, USA
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2003
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Vrije Universiteit Brussel
Brussels, BRU, Belgium
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