Biomedical subjects

Jacques Boschat

Publications and source records attributed to Jacques Boschat.

8 recordsLinked to original sources

PubMed2006

Accuracy of 16-detector multislice spiral computed tomography in the initial evaluation of dilated cardiomyopathy.

BACKGROUND: Multislice Computed Tomography (MSCT) recently proved its accuracy in the detection of coronary artery disease (CAD). It can also give information about left ventricular function and venous network anatomy. We here sought to validate a MSCT-based strategy in the initial evaluation of patients with dilated cardiomyopathy (DCM). METHODS: 36 patients with DCM underwent cardiac MSCT before conventional coronary angiography with ventriculography. We analysed arterial calcium score (Agatston score equivalent: ASE), coronary stenosis, left ventricular parameters and venous network. RESULTS: The sensitivity of a MSCT-based strategy in detecting significant CAD was 100% and the specificity 80%. The positive and negative predictive values were respectively 67% and 100%. For ASE <1.000 (75% of patients), MSCT detected all non-CAD patients without one (motion artifacts), enabling conventional angiography to be avoided in 21/27 patients (77.7%). For ASE > or =1000, MSCT enabled conventional angiography to be avoided in only 2/9 patients (22.2%). The ventricle was assessable in 83.4% (30 patients) on MSCT. Correlation coefficient Rs with ventriculography were 0.78 (p<0.0001), 0.77 (p<0.0001) and 0.82 (p<0.0001) respectively for end-diastolic volume, end-systolic volume and EF. The venous network was assessable in all patients both on MSCT and angiography. CONCLUSION: In patients undergoing an initial evaluation of DCM, MSCT appears to be an effective alternative to conventional angiography. The following attitude may be proposed: when ASE >1.000, conventional coronary angiography is mandatory due to MSCT's poor interest in such cases; when ASE <1.000, a contrast-enhanced MSCT may, when normal, replace coronary angiography.

Cardiomyopathy, Dilated↗

PubMed2006

Accuracy of multislice computed tomography in the preoperative assessment of coronary disease in patients with aortic valve stenosis.

OBJECTIVES: To evaluate multislice computed tomography (MSCT) as an alternative to coronary angiography, we prospectively studied its diagnostic accuracy for the detection of significant coronary artery lesions in patients with significant aortic valve stenosis undergoing valve surgery. BACKGROUND: In patients with aortic valve stenosis, coronary angiography is still recommended before surgery. Multislice computed tomography is a promising noninvasive technique for the detection of significant coronary artery lesions. METHODS: Fifty-five consecutive patients scheduled for coronary angiography in the preoperative assessment of aortic valve stenosis underwent 16-slice MSCT 24 h before coronary angiography. We analyzed coronary lesions, image quality, and arterial calcium score. RESULTS: The sensitivity of the MSCT-based strategy in detecting significant stenosis was 100%, and its specificity 80%. The positive and negative predictive values were respectively 55% and 100%. For calcium scores <1,000 (77% of patients), MSCT detected all patients without coronary artery disease, enabling conventional coronary angiography to be avoided in 35 of 55 cases (80%). For calcium scores >1,000, MSCT enabled conventional coronary angiography to be avoided in only 6% of cases, either because significant stenosis was found with a possible indication of revascularization, or because the examination was not interpretable. CONCLUSIONS: The results of this initial experience in relatively few patients suggest that MSCT-based coronary angiography may serve as an alternative to invasive coronary angiography to rule out significant coronary artery disease in patients scheduled for elective aortic valve replacement. Larger studies are necessary to fully explore the potential of coronary MSCT to improve preoperative risk stratification.

Aged↗

PubMed2006

Multi-slice computer tomography of left ventricular function with automated analysis software in comparison with conventional ventriculography.

PURPOSE: To evaluate the accuracy of left ventricular volumetric and functional parameters from multi-slice computed tomography using automated analysis software, and to correlate results with those of invasive left ventriculography. MATERIALS AND METHODS: In 145 consecutive patients (mean age, 61 years+/-12) known or suspected to have coronary artery disease, a 16-channel multi-slice computed tomography (Philips Mx8000 IDT 16) was performed using a standard technique. Using short-axis secondary multi-slice computed tomography reformations, we determined end-diastolic and end-systolic left ventricular volumes and ejection fraction with a commercially available analysis software capable of automated contour detection. Conventional left ventriculography was performed according to standard techniques within the following 24 h. Bland-Altman analysis was performed to calculate the limits of agreement and systematic errors between multi-slice computed tomography and conventional left ventriculography. RESULTS: As determined by computer tomography, mean end-systolic (53+/-29 mL) left ventricular volumes had an acceptable correlation with conventional ventriculography (67+/-50 mL; r=0.74; p<0.001) and mean end-diastolic (119+/-33 mL) left ventricular volumes a poor correlation with conventional ventriculography measurements (154+/-69 mL; r=0.41). Left ventricular ejection fraction (57%+/-14 versus 55%+/-14 for conventional ventriculography; r=0.79) showed a very good correlation (p<0.001). Bland-Altman analysis showed acceptable limits of agreement (+/-9.2% for ejection fraction) without systematic errors. CONCLUSION: The use of a multi-slice computed tomography with an automatic calculation software has a good correlation with conventional ventriculography findings and could accurately assess left ventricular function, but should not be used for ventricular volumes, because of biased estimations.

Cineradiography↗

PubMed2005

Noninvasive assessment of left main coronary stent patency with 16-slice computed tomography.

We investigated the ability of 16-slice computer tomography (CT) to discriminate any restenosis after left main coronary artery stenting in 29 consecutive patients. CT was able to detect all stents and analyze the lumen properly in 27 of 29 cases. With the exception of arrhythmic or heavily calcified segments, multislice CT provides a noninvasive alternative to conventional coronary angiography in the follow-up of left main angioplasty with stenting.

Coronary Angiography↗

PubMed2004

Evolution of spontaneous atherosclerotic plaque rupture with medical therapy: long-term follow-up with intravascular ultrasound.

BACKGROUND: Ruptured coronary atheromatous plaque is generally considered to involve a high risk of subsequent clinical events. Few data are available on the natural evolution of non-culprit-lesion ruptured plaque. We therefore used serial intravascular ultrasound (IVUS) to study how such lesions, detected in the context of a first acute coronary syndrome with elevated troponin I levels, develop. METHODS AND RESULTS: Fourteen patients with 28 distinct plaque ruptures (2+/-1 per patient) without significant associated stenosis (minimal lumen cross-sectional area >4 mm2) were included and systematically treated with 40 mg statin and antiplatelet agent (clopidogrel and aspirin for > or =9 months). Mean clinical and IVUS follow-up was 22+/-13 months (median, 22 months). No clinical event related to the lesion under study occurred. On final IVUS examination, half (14 of 28) of the ruptured plaques had healed, and the degree of stenosis tended to diminish (stenosis, 22+/-17% versus 29+/-17% at baseline; P=0.056). No healing-prediction criterion could be identified. CONCLUSIONS: Nearly 2 years of follow-up found that spontaneous coronary atheromatous plaque rupture without significant stenosis detected on first acute coronary syndrome healed without significant plaque modification in 50% of cases with medical therapy.

Aged↗

PubMed2003

Intravascular ultrasound-guided balloon angioplasty compared with stent: immediate and 6-month results of the multicenter, randomized Balloon Equivalent to Stent Study (BEST).

BACKGROUND: Balloon angioplasty guided by intravascular ultrasound (IVUS) makes it possible to choose the balloon size according to the true vessel diameter and to detect suboptimal results requiring subsequent stent implantation. The Balloon Equivalent to STent (BEST) study aimed to assess whether this strategy would give the same results as systematic stenting. METHODS AND RESULTS: A total of 132 of 254 patients were randomized to IVUS-guided percutaneous transluminal coronary angioplasty (aggressive PTCA), and 122 were randomized to stenting (stent group). We hypothesized that a difference of <8% in the 6-month angiographic restenosis rate (primary end point) could be considered noninferior. The aggressive PTCA procedure was longer and had a greater use of contrast medium than stenting. In the aggressive PTCA group, crossover to stent was needed in 58 patients (44%). At 6 months, 20 of 119 patients (16.8+/-6.7%) in the aggressive PTCA group and 21 of 116 patients (18.1+/-7.0%) in the stent group had restenosis. The difference was -1.3%, with an upper limit of 95% confidence interval of 7.1% (ie, less than the noninferiority boundary). The in-stent restenosis rate was higher in the stent group (15.5% versus 5%; P=0.02). The differences in minimum lumen diameter, lumen cross-section area, and 1-year event rate were not significant. CONCLUSIONS: A strategy of IVUS-guided angioplasty with provisional stenting is feasible and safe. At the cost of a more complex procedure, it reduces the stent rate by half, with similar 6-month angiographic IVUS and clinical outcome compared with stent implantation.

Angioplasty, Balloon↗

PubMed2003

Direct coronary stenting without balloon predilation of lesions requiring long stents: immediate and 6-month results of a multicenter prospective registry.

To assess the outcomes of direct coronary stenting (DS) using long stents and examine predictive factors of DS failure, this prospective multicenter registry included 128 consecutive patients who underwent the implantation of stents >or= 18 mm in length without balloon predilation for de novo coronary artery stenoses. Mean lesion and stent lengths were 20.7 +/- 5.4 and 21.4 +/- 3.8 mm, respectively. Rates of DS success, lesion success, and primary success were 82%, 99%, and 97.7%, respectively. At 6 months, rates of MACE and TVR were 12.5% and 6.3%, respectively. In multivariate analysis, factors predictive of DS failure vs. DS success were presence of calcifications (78% vs. 45%; P = 0.004) and reference vessel diameter (2.77 +/- 0.4 vs. 3.13 +/- 0.42 mm; P = 0.0002). DS of complex lesions with stents >or= 18 mm in length was performed safely and with a high success rate. This strategy was less successful in the treatment of small vessels and in presence of calcifications.

Aged↗

PubMed2002

Is coronary stent deployment and remodeling affected by predilatation? An intravascular ultrasound randomized study Stenting with or without predilation: an IVUS study.

In this intravascular ultrasound (IVUS) randomized trial we compared a strategy of direct stenting (DS) without predilation (n = 30) vs. conventional stenting with predilation (SWP) (n = 30) in patients with suitable type A or B non-calcified lesions in native vessels > or = 3 mm. Optimal deployment was achieved using angiographic criteria without interactive IVUS. The goal of our study was to determine whether stent expansion and coronary remodeling were similar. Maximal pressure inflation was comparable in the two groups (11.4 +/- 2.2 vs. 11.8 +/- 1.9 atm; NS). Stent deployment was obtained in all patients with complete apposition to the vessel wall. DS and SWP resulted in comparable lumen enlargement (5.4 +/- 2.5 vs. 5.5 +/- 2.1 mm2) with an identical mechanism: 66% of lumen enlargement was due to increased enlarged elastic membrane (EEM)-cross sectional area (CSA) (delta = 3.7 +/- 2.1 mm2 and delta = 2.4 +/- 6.8 mm2, respectively, p < 0.49) and 34% was due to a reduced P + M-CSA (delta = 0.02 +/- 6.9 mm2 and delta = 1.2 +/- 6.3 mm2, respectively, p < 0.50). We conclude that at the same maximal pressure inflation the mechanisms of stent expansion are similar in both DS and SWP groups. In this observational study, the IVUS data showed clearly under-expansion of stents in both groups in comparison with previously published CSA values (minimum stent CSA of 7.5 mm2).

Aged↗