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Edouard Cheneau

Publications and source records attributed to Edouard Cheneau.

31 records · Page 2Linked to original sources
PubMed2002

How to fix the edge effect of catheter-based radiation therapy in stented arteries.

BACKGROUND: Edge stenosis remains a serious limitation of catheter-based vascular brachytherapy (VBT). This study aims to identify the mechanisms and evaluate strategies to minimize edge restenosis in patients treated with VBT. METHODS AND RESULTS: Thirty-four porcine stented coronary arteries were irradiated (doses of 15 or 22 Gy) with (192)Ir trains of either 6 seeds (23 mm) with 0 mm coverage at the distal stent edge and 10 mm at the proximal stent edge or 14 seeds (55 mm) centered at the distal edge of the stent with 27.5 and 14.5 mm coverage at the distal and proximal edges, respectively. After VBT, an additional 13-mm stent was positioned overlapping the distal margin of the first stent. Animals were killed at 28 days, and arteries were analyzed. Longer radiation margins were associated with reduced intimal area (IA) at the stent edge: 2.3+/-0.9, 3.6+/-2.0, and 5.3+/-2.2 mm(2) with 15 Gy for a radiation margin of 14.5, 10, and -13 mm (-13 versus 10, P=0.06; 10 versus 14.5, P=0.06). Additional stenting was associated with an increase of IA: 4.0+/-2.3 mm(2) at the overlapped segment. Increasing the dose to 22 Gy resulted in a reduction of the IA at the overlap segment to 1.31+/-0.57 mm(2) with 14 seeds (27.5 mm coverage) but was not helpful with 6 seeds (0 mm coverage): IA, 5.56+/-2.28 mm(2). CONCLUSIONS: Extending the radiation margins to 14.5 mm from each end of the stent minimized the edge-effect phenomenon. A higher dose is essential to eliminate further increases in IA at the overlapped segment with additional stents.

Animals↗
PubMed2002

Effectiveness of radioactive tungsten source in the prevention of restenosis in stented porcine coronary arteries.

PURPOSE: Intracoronary radiation has shown the potential to inhibit neointimal proliferation in porcine models of restenosis. The objective of this study was to determine whether intracoronary radiation using a new coiled wire of tungsten-188 ((188)W), a pure beta emitter (half-life 69.4 days) is safe. In addition, a dose of 0 Gy, 18 Gy, or 25 Gy prescribed to 2 mm from the center of the source and delivered intraluminally is sufficient to prevent restenosis and free from adverse effects. METHODS AND MATERIALS: Ten domestic swine underwent 13-mm stent implantation (SI) into two arteries, left anterior descending plus either the left circumflex or right coronary artery. After SI, a closed-end lumen radiation catheter was inserted to the treated artery and a 40-mm coiled (188)W source was manually delivered to cover the stented segment and its margins. A total of 20 arteries were randomized to treatment with a radiation dose of 0, 18 Gy, or 25 Gy delivered to 2 mm depth from the center of the source. Four weeks after the procedure, the swine underwent angiography and intravascular ultrasound using automated pullback at 0.5 mm/s. before being killed and the arteries perfusion fixed. Histopathologic and histomorphometric analyses were performed at 28 days after injury and radiation. RESULTS: Irradiation with (188)W at a dose of 25 Gy after SI significantly inhibited neointima formation (intimal area: 1.05 +/- 0.64 vs. 2.75 +/- 0.99 mm(2), p < 0.01) and at an 18 Gy dose of radiation (intimal area: 1.73 +/- 0.49 vs. 2.75 +/- 0.99 mm(2)), as compared to controls. One artery receiving 18 Gy and two arteries receiving 25 Gy were totally occluded at follow-up due to thrombus formation but no edge stenosis was observed in any of the irradiated arteries. CONCLUSIONS: Intracoronary radiation therapy using a new coiled wire of (188)W source delivered after SI appeared to be safe and well tolerated. The radiation doses demonstrated efficacy in reducing neointima formation in the porcine coronary stent injury model.

Animals↗
PubMed2002

Twelve versus six months of clopidogrel to reduce major cardiac events in patients undergoing gamma-radiation therapy for in-stent restenosis: Washington Radiation for In-Stent restenosis Trial (WRIST) 12 versus WRIST PLUS.

BACKGROUND: Intracoronary gamma-radiation reduces recurrent in-stent restenosis (ISR). Late thrombosis was attenuated with 6 months of aspirin and clopidogrel. We aimed to find out whether 12 months of aspirin plus clopidogrel is superior to a strategy of 6 months after radiation therapy for patients with ISR. METHODS AND RESULTS: One hundred twenty consecutive patients with diffuse ISR in native coronaries and vein grafts with lesions <80 mm in length underwent PTCA, laser ablation, or rotational atherectomy. Additional stents were placed in 39 patients (33%). After the intervention, a ribbon with different trains of radioactive 192Ir seeds was positioned to cover the treated site, and a dose of 14 Gy to 2 mm was prescribed. Patients were discharged with clopidogrel and aspirin for 12 months and followed up clinically. The cardiac clinical event rates at 15 months were compared with the gamma-treated (n=120) patients of the WRIST PLUS study (only 6 months of antiplatelet therapy). Whereas the late thrombosis rates were similar (3.3% for the group given 12 months of antiplatelet therapy versus 4.2% for the group given 6 months, P=0.72), the group treated with 12 months of antiplatelet therapy had a rate of 21% for major adverse cardiac events and 20% for target-lesion revascularization compared with 36% (P=0.01) and 35% (P=0.009), respectively, in patients who were treated with only 6 months of clopidogrel. CONCLUSIONS: Twelve months of clopidogrel is superior to 6 months in reducing overall major cardiac events and revascularization rates at 15 months for patients with ISR treated with gamma-radiation. At least 12 months of clopidogrel therapy should be recommended for patients undergoing radiation therapy for ISR.

Aspirin↗
PubMed2002

Elderly patients have a favorable outcome after intracoronary radiation for in-stent restenosis.

Intracoronary radiation therapy (IRT) reduces recurrent in-stent restenosis (ISR) by inhibition of smooth muscle cell proliferation. The ability of these cells to replicate is limited with age due to changes in the telomeres. The purpose of this study was to assess the effect of age on outcomes following IRT for ISR. We evaluated 1,088 patients with 6-month clinical follow-up who were enrolled in radiation trials for ISR using gamma- and beta-emitters. Patients were analyzed within and between IRT (n = 861) or placebo therapy (n = 227) in four age groups (< 55, 55-65, 66-75, > 75 years). Baseline characteristics were similar within each age group of IRT patients, except elderly patients (> 75 years) had a lower rate of diabetes (28% in patients > 75 years; P = 0.008) and a higher rate of previous CABG (59% in patients > 75 years; P < 0.001). The rate of target lesion revascularization (TLR) was reduced in the elderly. TLR at 6 months was 18% in patients < 55 years, 21% in 55-65 years, 12% in 66-75 years, and 10% in patients > 75 (P = 0.009). The MACE rate at 6 months was 21% in patients < 55 years, 29% in 55-65 years, 26% in 66-75 years, and 17% in patients > 75 (P = 0.03). No effect of age was seen in placebo patients. IRT-treated patients had reduced MACE compared to placebo in all age groups, driven by reduced target vessel revascularization. Age was an independent predictor of MACE at 6 months (OR = 0.8; CI = 0.70-0.93; P = 0.004). Angiographic restenosis was not clearly associated with need for TLR in patients > 75 years. In elderly patients (> 75 years) treated with IRT for ISR, the rate of TLR was significantly reduced compared to younger patients. However, this reduction in TLR was not associated with a reduction in angiographic restenosis, suggesting that TLR should not be used as a surrogate for angiographic evaluation.

Age Factors↗
PubMed2002

Do differences in baseline characteristics or in management account for the poorer in-hospital and subsequent outcome after myocardial infarction in diabetics? Data from a large unselected cohort.

OBJECTIVE: There is an excess mortality after myocardial infarction in diabetics, but also documented significant differences in the characteristics of MI and in management between diabetics and non-diabetics. The aim of this prospective study in a large unselected patient cohort in a single French region was to determine if baseline characteristics, management, or in-hospital and one-year mortality differed in diabetic and non-diabetic patients with myocardial infarction. METHODS AND RESULTS: Data were prospectively collected in consecutive patients with myocardial infarction admitted to all hospitals in three departments in the Rhone-Alpes region between September 1, 1993 and January 31,1995. Among the 2,297 patients, 410 patients (17.8%) were diabetic. Although diabetics were older than non-diabetics (70.3 vs. 67.8 years; p < 0.0004), and less likely to receive thrombolysis (31% vs. 36%; p = 0.043), in-hospital mortality was not significantly higher (17.3% vs. 14.7%) than in non-diabetics. In multivariate analysis, diabetes was a significant predictor of one-year mortality (relative risk: 1.41; 95% CI = 1.10 - 1.79; p = 0.0063) but not of in-hospital mortality (relative risk: 1.2; 95% CI = 0.9 - 1.7; p = 0.25). Multivariate predictors of in-hospital and one-year mortality in diabetics were age and Killip class at admission. CONCLUSIONS: In this large unselected French cohort, diabetes mellitus was a significant predictor of one-year but not of in-hospital mortality after myocardial infarction in a French region. This negative effect of diabetes on mortality was not related to differences in baseline characteristics, or in initial or post-discharge management between diabetics and non-diabetics.

Aged↗
PubMed2002

Clinical trials of intracoronary gamma radiation therapy for in-stent restenosis.

The only gamma emitter used in clinical trials for in-stent restenosis is 192Iridium (192Ir). The efficacy of intracoronary gamma radiation therapy in reducing clinical and angiographic restenosis in patients with in-stent restenosis has been established. This review is intended to give an overview of the clinical trials utilizing gamma vascular brachytherapy in patients with in-stent restenosis and give insight into the future of intracoronary radiation therapy.

Angioplasty, Balloon, Coronary↗
PubMedDate not supplied

The initial course of in-stent restenosis influences the response to vascular brachytherapy.

BACKGROUND: Vascular brachytherapy (VBT) reduces the rate of recurrence of in-stent restenosis (ISR) by inhibiting intimal proliferation. However, the rate of cell proliferation, reflected by the speed of ISR development, is variable in ISR lesions and might influence the responsiveness of ISR to radiation. The aim of this study was to determine the influence of the initial ISR course on the clinical outcome of patients undergoing VBT. METHODS: In 1165 patients treated for ISR with VBT in the WRIST studies, we determined the time for ISR (time between initial stent implantation and restenosis), the time for VBT treatment (time between stent implantation and VBT), and previous ISR treatment with conventional strategies. Target lesion revascularization (TLR) at 6 months was available in all patients. RESULTS: Previous ISR treatment did not influence the result of VBT (TLR was 17% vs. 16% without previous angioplasty). Time to ISR influences the outcome of patients undergoing VBT; TLR decreased when ISR occurred later. TLR was 18.2%, 16.7%, and 11.1% when time to ISR was <90, 90-2700, and >270 days, respectively, P=.03. Early ISR (time for ISR <90 days) is a factor for radiation failure (OR=2.1, P<.05). In patients with early ISR, TLR is lower when VBT is delayed; TLR was 11% if performed 90 days after stent implantation as compared to 22% if VBT is performed early (<90 days), P<.05. CONCLUSION: The course of ISR development affects the long-term efficacy of VBT. Early restenosis remains a factor of treatment failure in the VBT era. Delaying VBT beyond 90 days after stent implantation reduces the rate of subsequent revascularization in these patients.

Aged↗
PubMedDate not supplied

The proximal location of stenosis in the left anterior descending coronary artery is not a predictive factor of worse outcome in the era of the stent.

BACKGROUND: Patients treated for lesions in the proximal left anterior descending coronary artery (P-LAD) have worse outcome after balloon angioplasty as compared to patients treated for lesions in the distal left anterior descending coronary artery (D-LAD). We sought to examine if this discrepancy was still observed after stenting. METHODS: A total of 676 consecutive patients with a symptomatic monovessel disease in the LAD artery who underwent angioplasty with stenting were prospectively entered into a dedicated database. Among this cohort, 322 lesions were located in P-LAD and 354 in D-LAD. Patients with total occlusion, acute myocardial infarction (MI) or restenosis were excluded. RESULTS: Procedural characteristics were similar in the two groups. Procedural success was high with the same rates of in-hospital death and Q-wave MI for patients treated in P-LAD and D-LAD. At 1 year, the rate of target lesion revascularization (TLR) was 13.9% in the P-LAD group and 16.3% in the D-LAD group (P = .79), and the rate of event-free survival was 81.9% and 81% (P = .67), respectively. The treatment of ostial lesions (n = 23) was not related to worse outcome. In multivariate analysis, lesion location was not a predictor of major adverse cardiac events (MACE). CONCLUSION: This study shows that stenting of lesions in the P-LAD is as effective and safe as treatment of lesions located in D-LAD. Therefore, when stenting is feasible, the location of the lesion in the LAD is not predictive of worse outcome and, consequently, should not be taken into account in the choice of the revascularization strategy.

Aged↗
PubMedDate not supplied

Antioxidants attenuate atherosclerotic plaque development in a balloon-denuded and -radiated hypercholesterolemic rabbit.

BACKGROUND: Oxidation of lipoproteins is considered to be a key contributor to atherogenesis. Antioxidants are potential antiatherogenic agents because they can inhibit lipoprotein oxidation. Radiation has been shown to increase oxidative stress leading to increased atherogenesis. This study is designed to test the potential of antioxidants to inhibit atherosclerotic plaque progression in balloon-denuded and -radiated rabbits. METHODS AND RESULTS: Two groups of New Zealand white rabbits (n=36) were fed with 1% cholesterol diet (control diet) or with 1% cholesterol diet containing a mixture of various antioxidants for 1 week. Iliac arteries in all the animals were balloon denuded and continued to fed with 0.15% cholesterol diet or 0.15% cholesterol diet containing antioxidants (antioxidant diet). Four weeks after balloon denudation one iliac artery in 12 animals from each group was radiated and all the animals were continued to be fed with the same diet. Four weeks after radiation animals were sacrificed and morphometric analysis of iliac arteries (n=12) in nonradiated and radiated animals were performed. Plaque area (PA) in the rabbits that were fed with cholesterol diet is 0.2+/-0.12 mm2, and it is increased by 2.75-fold (P<.05) in the radiated arteries of animals fed with cholesterol diet. Plaque area in the animals fed with antioxidant diet is 50% less then the one in the animals fed with cholesterol diet. Similarly, plaque area in radiated arteries of the animals fed with antioxidant diet is 50% less then the animals fed with cholesterol diet. CONCLUSION: Antioxidants significantly attenuate atherosclerotic plaque progression in balloon-injured and -radiated hypercholesterolemic rabbits.

Animals↗
PubMedDate not supplied

Acute procedural complications and in-hospital events after percutaneous coronary interventions: eptifibatide versus abciximab.

BACKGROUND: Glycoprotein IIb/IIIa antagonists reduce peri-angioplasty ischemic complications and improve in-hospital outcome in patients undergoing percutaneous coronary interventions (PCI). Prior studies have demonstrated favorable results with both eptifibatide and abciximab. The purpose of this study was to assess whether there are any differences in rates of acute procedural complications and in-hospital events with the use of these two agents. METHODS: A retrospective review of 359 elective PCIs from June 1998 to August 2000 identified 152 PCIs treated with eptifibatide (bolus 180 microg/kg, infusion 2 microg/kg/min for 12-48 h) and 205 PCIs treated with abciximab (bolus 0.25 mg/kg, infusion 10 microg/min for 12 h). All patients received IIb/IIIa antagonists at the initiation of the intervention. RESULTS: The clinical demographics, the angiographic morphology, the indications, and the procedural details were similar in both groups. In the eptifibatide group, the maximum ACT was lower (235+/-45 vs. 253+/-40, P<.0001). The incidence of major procedural and in-hospital events was compared. Eptifibatide and abciximab had similar rates of major complications (death or myocardial infarction) (1.4% vs. 2.9%), repeat PTCA (3.4% vs. 1.9%), and major bleeding (3.3% vs. 4.3%). CONCLUSIONS: Eptifibatide is comparable to abciximab in regards to acute procedural complications and in-hospital events after PCI.

Abciximab↗
PubMedDate not supplied

Radiation-induced atherosclerotic plaque progression in a hypercholesterolemic rabbit: a prospective vulnerable plaque model?

PURPOSE: Human observations provide rich soil for making hypotheses, but good animal models are essential for understanding the disease and to test treatment modalities. Currently, there is no standard animal model of vulnerable plaque; therefore, the purpose of this study is to develop a pathophysiologically relevant vulnerable plaque model. METHODS: New Zealand White rabbits were fed with 1% hypercholesterolemic (HC) diet for 7 days, followed by balloon denudation of both the iliac arteries, and continued on 1% HC diet. Four weeks later, in 12 rabbits one of the iliac arteries was radiated (192-Ir, 15 Gy), and in five rabbits both the iliac arteries were sham treated. Following that, rabbits were fed with 0.15% HC diet. Four weeks later, arteries were processed for histomorphometry or immunohistochemistry. RESULTS: Serum cholesterol levels were similar in all the groups. In radiated arteries, plaque area was significantly larger (32% larger then in sham). Macrophage-positive area in radiated arteries was 2.4 times greater than the macrophage-positive area in the nonradiated arteries. The area positive for macrophages is also positive for metalloproteinases (MMP)-1. The extent of alpha-actin positive area was significantly less (2.3-fold) in radiated arteries. CONCLUSION: The atherosclerotic plaque developed in the current model is predominantly composed of macrophages expressing metalloproteinases with few smooth muscle cells (SMC)--a characteristic of vulnerable plaque. The animal model presented in this study can elucidate at least part of the mechanism of plaque vulnerability and could be used to test treatment modalities to test plaque stability.

Animals↗