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Pim J De Feyter

Publications and source records attributed to Pim J De Feyter.

9 recordsLinked to original sources
PubMed2006

Clinical imaging of the vulnerable plaque in the coronary arteries: new intracoronary diagnostic methods.

Rupture of a vulnerable plaque is the main cause of acute coronary syndromes and myocardial infarction. The features of rupture-prone atherosclerotic plaques have been previously described by pathologists. However, identification of vulnerable plaques in vivo is essential to study their natural history and to evaluate potential treatment modalities. Coronary angiography is the gold standard for the diagnosis of coronary artery disease, but it is unable to distinguish between stable and unstable plaques and to accurately predict future cardiac events. This current perspective describes the recently developed invasive imaging techniques to detect atherosclerotic vulnerable plaques in the coronary tree.

Angioscopy↗
PubMed2005

Angiographic, intravascular ultrasound, and fractional flow reserve evaluation of direct stenting vs. conventional stenting using BeStent2 in a multicentre randomized trial.

AIMS: Direct stenting (DS) may not be as safe and effective as conventional stenting. The objective was to demonstrate equivalence of post-procedural mean luminal diameter (MLD) by angiography after BeStent2 placement between DS and pre-dilatation (PD) strategy. METHODS AND RESULTS: Two hundred and two patients with a single de novo lesion (diameter >/=3.0 mm and length </=13 mm) were randomized to DS (n=101) vs. PD. Stent deployment was guided by on-line quantitative coronary angiography (QCA). A second randomization assigned half of the patients to intravascular ultrasound (IVUS) and fractional flow reserve (FFR) assessment. QCA was repeated at 6 months. Baseline characteristics were similar. Crossover to PD was necessary in seven DS patients. Stent deployment was successful in 97% (DS) and 98% (PD). The post-procedural MLD was 2.79+/-0.45 mm (DS) and 2.76+/-0.40 mm (PD). The null-hypothesis of non-equivalence could be rejected (95% one-sided; P=0.0003). The minimum stent area (IVUS) was 7.89+/-1.75 mm(2) (DS) and 8.07+/-2.37 mm(2) (PD; P=0.69), with an FFR of 0.92+/-0.07 and 0.92+/-0.05, respectively (P=0.97). Major adverse cardiac event rates at 6 months were 9% (DS) and 11% (PD; P=0.93). Target lesion re-angioplasty was 6% (DS) and 5% (PD; P=0.77). The in-stent restenosis rate by QCA was 7.4% (DS) and 6.8% (PD; P=0.87). CONCLUSION: DS with BeStent2 is equivalent to PD. Both strategies resulted in a low angiographic restenosis rate.

Angioplasty, Balloon, Coronary↗
PubMed2005

Influence of increasing convolution kernel filtering on plaque imaging with multislice CT using an ex-vivo model of coronary angiography.

PURPOSE: To assess the variability in attenuation of coronary plaques with multislice CT-angiography (MSCT-CA) in an ex-vivo model with varying convolution kernels. MATERIALS AND METHODS: MSCT-CA (Sensation 16, Siemens) was performed in three ex-vivo left coronary arteries after instillation of contrast material solution (Iomeprol 400 mgI/ml, dilution: 1/80). The specimens were placed in oil to simulate epicardial fat. Scan parameters: slices 16/0.75 mm, rotation time 375 ms, feed/rotation 3.0 mm, mAs 500, slice thickness 1 mm, and FOV 50 mm. Datasets were reconstructed using 4 different kernels (B30f-smooth, B36f-medium smooth, B46f-medium, and B60f-sharp). Each scan was scored for the presence of plaques. Once a plaque was detected, the operator performed attenuation measurements (HU) in coronary lumen, oil, calcified and soft plaque tissue using the same settings in all datasets. The results were compared with T-test and correlated with Pearson's test. RESULTS: Overall, 464 measurements were performed. Significant differences (p<0.05) were found for the mean attenuation of lumen (B30f/B36f, B30f/B60f, B36f/B46f, B36f/B60f, and B46f/B60f), oil (B30f/B36f, B30f/B46f, B30f/B60f, B36f/B46f, and B46f/B60f), calcium (all kernels), and plaque (B30f/B36f, B30f/B46f, B30f/B60f, and B46f/B60f) using 4 different kernels. The attenuation values (mean+/-SD) within the lumen (246+/-6, 215+/-13, 248+/-5, and 270+/-7), oil (-123+/-3, -127+/-1, -121+/-6, and -127+/-4), calcified plaque tissue (703+/-334, 739+/-364, 817+/-381, and 1181+/-503), and soft plaque tissue (134+/-56, 111+/-49, 120+/-56, and 102+/-41) showed high correlation (p<0.001) when attenuation of all structures were compared in different kernels. CONCLUSIONS: Use of sharper convolution kernels significantly increases the attenuation of the calcium within coronary plaques and reduces the attenuation of soft plaque tissue.

Aged↗
PubMed2004

Geometry guided data averaging enables the interpretation of shear stress related plaque development in human coronary arteries.

The average low shear stress (SS) is known to determine predilection sites of atherosclerotic plaques. However, as plaques encroach into the lumen and thereby increase SS, interpretation of patient-specific data obtained at one moment in time regarding the influence of SS in the generation of atherosclerosis is not straightforward. This study aims to compare two methods of data analysis for the aid of data interpretation: (a) point-wise analysis of the raw data, (b) global analysis: to assess the history related natural SS distribution in coronary arteries by averaging the data in the axial vessel direction. Normal to mildly diseased human coronary arteries were investigated applying a combination of 3-D reconstruction technique and computational fluid dynamics (CFD). Point-wise analysis relating local wall thickness to local SS showed in only 4% of the cases an inverse relationship. In contrast, averaging the data in the axial vessel direction, showed in 38% a significant inverse relation between wall thickness and SS, resulting in an average negative slope of -0.70+/-0.46 mm/Pa. These data suggest that using a geometry guided way of data averaging may reveal history related effects of SS, which in part explains localization of atherosclerotic plaques.

Computer Simulation↗
PubMed2003

Evaluation of patients after coronary artery bypass surgery: CT angiographic assessment of grafts and coronary arteries.

PURPOSE: To evaluate the accuracy of electrocardiography (ECG)-gated multi-detector row computed tomography (CT) in enabling the detection of obstruction of both bypass grafts and coronary arteries in symptomatic patients who have undergone coronary artery bypass grafting. MATERIALS AND METHODS: ECG-gated contrast material-enhanced multi-detector row CT angiography was performed in 24 patients after bypass surgery. Two independent blinded observers evaluated all graft and coronary segments (> or =2.0-mm diameter) for occlusion and stenosis (50%-99% luminal reduction). Conventional angiography was regarded as the standard of reference. Descriptive parameters were calculated, and the results for arterial grafts, venous grafts, and coronary arteries, as well as for high and low heart rates, were compared by using a two-sided Fisher exact test. RESULTS: The following results were obtained by observers 1 and 2, respectively: Of the 60 venous graft segments, 60 (100%) and 57 (95.0%) were assessable, with an overall detection of all 17 occlusions (both observers) and three (50.0%) and five (83.3%) of six stenoses. Of 26 arterial graft segments, 19 (73.1%) and 15 (57.7%) were assessable. In the assessable segments, four of four (100%) and two of three (66.7%) stenoses and occlusions were detected, while one and two obstructions were located in nonassessable segments. Of 211 coronary segments, 146 (69.2%) and 140 (66.4%) were assessable, and detection of 50%-100% obstruction yielded a sensitivity of 89.9% (71 of 79) and 79.4% (54 of 68) and a specificity of 74.6% (50 of 67) and 72.2% (52 of 72) for each observer. Unlike the assessment of venous and arterial grafts, assessment of the coronary arteries with multi-detector row CT was significantly better in patients with low heart rates (P <.01). CONCLUSION: Multi-detector row CT allows noninvasive angiographic evaluation of both coronary arteries and bypass grafts in patients who have undergone bypass surgery. Multi-detector row CT is more effective in examining venous grafts compared with arterial grafts and diffusely diseased coronary arteries.

Adult↗
PubMed2001

The Lescol(R) Intervention Prevention Study (LIPS): a double-blind, placebo-controlled, randomized trial of the long-term effects of fluvastatin after successful transcatheter therapy in patients with coronary heart disease.

BACKGROUND: The 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors (statins) inhibit atherosclerosis and reduce both morbidity and mortality in patients with coronary heart disease. No randomised prospective study, however, has investigated the long-term effect of statins on clinical outcomes in patients who have undergone first successful transcatheter therapy. METHODS: The Lescol((R)) Intervention Prevention Study (LIPS) is a double-blind randomized trial designed to compare the effect of fluvastatin (Lescol) with that of placebo on the time which patients with serum cholesterol >/= 3.5 mmol/l and < 7.0 mmol/l (135-270 mg/dl) remain free of major adverse cardiac events (MACE) after successful first transcatheter therapy (TCT). Patients, aged 18-80 years inclusive, will be randomized in a 1 : 1 ratio to receive fluvastatin, 40 mg, or placebo, twice daily for three to five years. The primary endpoint is the survival time during which patients remain MACE free after first TCT. Secondary endpoints are the incidence of MACE, noncardiac death, hospitalization for other atherosclerotic diseases, changes in serum lipid concentrations and anginal status. SUMMARY: LIPS is unique because it is the first study that will investigate whether MACE can be prevented or reduced by fluvastatin in patients who have undergone successful first transcatheter therapy for coronary heart disease.

Journal Article↗
PubMed2000

Low rates of clinical restenosis with the new flexible stainless steel tube intracoronary stent: the R Stent. A six-month safety and feasibility study.

BACKGROUND: Coronary stents have been used with increasing frequency and in increasingly complex coronary lesions for the treatment of symptomatic coronary artery disease. A new stainless steel coronary stent, the R Stent, has been designed to provide maximum flexibility for tracking and high radial strength post-deployment. AIMS: To assess the safety and feasibility of the R Stent in patients with coronary artery disease. Specific objectives were to assess the R Stent's deployment success, angiographic and procedural success (< 20% residual stenosis and TIMI 3 flow), safety (absence of complications), 30-day and six-month clinical follow-up. METHODS: Between April 1998 and January 1999, stent deployment was attempted in 36 lesions in 30 patients with stable (43%) or unstable (57%) angina pectoris and 29/36 of the lesions were anatomically complex. Treated lesions were in the LAD (n = 15), RCA (n = 13) or LCX (n = 8). RESULTS: Stent deployment was achieved in 97% with one crossing failure in a patient with a long, calcified, proximal LAD lesion. After the procedure, patients were scheduled for one- and six-month clinical follow-up. One patient experienced a non-Q-wave myocardial infarction in hospital. At one month, there were no additional complications. Only one patient experienced recurrence of angina (CCS class 2) within the 30 days. At six-month follow-up, one sudden death had occurred. Three (10%) patients had anginal complaints, one of them received target lesion repeat PTCA. All other patients (87%) were event- and angina-free. CONCLUSION: This first clinical experience with the R Stent shows acceptable feasibility and safety with good long-term clinical results.

Journal Article↗
PubMedDate not supplied

[Normal anatomy of the vessels of the heart with 16-row multislice computed tomography].

Nowadays, cardiac imaging is not part of the clinical routine for the radiologist. Multislice Computed Tomography (MSCT) with 4 rows allowed to start the non invasive evaluation of coronary arteries. The introduction of 16-row MSCT has significantly improved the performance and diagnostic accuracy of this technique, so far that MSCT angiography has been advocated as a potential clinical tool for the study of coronary artery disease. Therefore, it is mandatory to understand normal cardiac and coronary anatomy in order to evaluate the presence and severity of coronary artery disease. The anatomical visualisation provided by MSCT differs from the one of conventional coronary angiography because it is not a simple "lumenology" but it is capable to provide information on the vessel wall, until now only achieved by invasive techniques such as intravascular ultrasound or optical coherence tomography, and on neighbouring structures. Aim of this works is to provide the basics of anatomy of the vessels of the heart applied to MSCT.

Coronary Angiography↗