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Biomedical subjects

E Van Belle

Publications and source records attributed to E Van Belle.

At least 19 recordsLinked to original sources
PubMed2006

Functional mitral regurgitation and chronic heart failure.

Functional mitral regurgitation (MR) frequently develops during the progression of chronic heart failure and predicts poor outcome. Impaired left ventricular (LV) function, LV remodeling associated with papillary muscle apical displacement and annular enlargement result in decreased mitral closing forces and tenting of the mitral valve at closure. Reduced closing forces and tenting both promote MR. Active myocardial ischemia, myocardial asynchronism and excessive loading conditions worsen MR at rest and during exercise. The therapeutic target in functional MR is the left ventricle and not the valve.

Adrenergic beta-Antagonists↗
PubMed2005

Cardiac resynchronisation therapy reduces functional mitral regurgitation during dynamic exercise in patients with chronic heart failure: an acute echocardiographic study.

OBJECTIVES: To assess non-invasively the acute effects of cardiac resynchronisation therapy (CRT) on functional mitral regurgitation (MR) at rest and during dynamic exercise. METHODS: 21 patients with left ventricular (LV) systolic dysfunction and functional MR at rest, treated with CRT, were studied. Each patient performed a symptom-limited maximal exercise with continuous two dimensional Doppler echocardiography twice. The first exercise was performed with CRT; the second exercise was performed without CRT. Mitral regurgitant flow volume (RV), effective regurgitant orifice area (ERO) and LV dP/dt were measured at rest and at peak exercise. RESULTS: CRT mildly reduced resting mitral ERO (mean 8 (SEM 2) v 11 (2) mm(2) without CRT, p = 0.02) and RV (13 (3) v 18 (3) ml without CRT, p = 0.03). CRT attenuated the spontaneous increase in mitral ERO and RV during exercise (1 (1) v 9 (2) mm(2), p = 0.004 and 1 (1) v 8 (2) ml, p = 0.004, respectively). CRT also significantly increased exercise-induced changes in LV dP/dt (140 (46) v 479 (112) mm Hg/s, p < 0.001). CONCLUSION: Attenuation of functional MR, induced by an increase in LV contractility during dynamic exercise, may contribute to the beneficial clinical outcome of CRT in patients with chronic heart failure and LV asynchrony.

Aged↗
PubMed2004

[The use of the RESCUE thromboaspiration system in acute coronary syndrome].

Interventional procedures associated with acute coronary syndromes or performed on saphenous bypass grafts frequently lead to embolic complications, resulting in no-reflow phenomenon, side-branch occlusion, or peri-procedural infarction. The RESCUE thrombo-aspiration system was used in 19 percutaneous coronary interventions. After initial use of the aspiration device, 81% of procedures were followed by stent deployment. TIMI flow 2 or higher was present in 42% at the beginning of the procedure and in 95% at the end. In-hospital MACE rate was 4.76%. This relatively user-friendly technique appears rapid and efficacious in the case of visible intracoronary thrombus.

Acute Disease↗
PubMed2004

[Restenosis and vascular response after angioplasty: physiopathological data].

Our purpose is to review the different mechanisms involved in the vascular response following percutaneous coronary revascularization, and their role in thrombotic complications and in restenosis. Specificities related to the various techniques of percutaneous coronary revascularization (balloon angioplasty, coronary stents, brachytherapy, drug eluting stents) are discussed.

Angioplasty, Balloon, Coronary↗
PubMed2004

[Does diabetes affect therapy in coronary patients? Revascularisation].

Techniques of myocardial revascularisation are very commonly employed in diabetic patients. In unstable angina, the reported data suggests a very significant benefit of an invasive strategy for the diabetic patient. In stable angina, subgroups analysis of randomised clinical trials carried out over ten years ago showed a better outcome after surgery in cases of multivessel disease. What has been the impact of technical advances archived since then? Active stents and antiplatelet drugs have considerably improved the outcome of diabetics treated by angioplasty. Cardiac surgery has also made considerable progress with the systematic use of arterial grafts. New randomised clinical trials are underway to determine the modern options of myocardial revascularisation for diabetic patients.

Coronary Artery Disease↗
PubMed2003

[Cell therapy to treat heart failure].

INTRODUCTION: Systolic heart failure is mainly due to a decreased left ventricular systolic function after myocardial infarction. Despite significant improvements in medical management of heart failure, the prognostic remains poor, with a 5-years survival only of 30%. PURPOSE: Current treatments are only able to delay progression toward end-stage heart failure. Heart transplantation is accessible only for selected patients. Thus, in the context of post-myocardial infarction, cell therapy appears to be a new original technique, available for the majority of patients and potentially non-invasive. CONCLUSION: After promising results in experimental models, a phase I clinical trial has been conducted in France, showing the feasibility of intracardiac autologous skeletal myoblast implantation. Other studies in Europe and USA are currently testing a variety of cells and delivery systems. A phase II-trial will begin in France.

Animals↗
PubMed2002

[Coronary thrombosis imaging in humans].

The identification of coronary thrombosis in humans has important prognostic and therapeutic implications. Its recognition calls for invasive techniques: angioscopy, coronarography, and endocoronary ultrasound. Angioscopy allows visualisation of the arterial surface and the detection of thrombus with great sensitivity. Its presence is exclusive to the acute coronary syndromes: 67% in unstable angina, and 75% in myocardial infarction, although it is only present in 27% of cases of stable angina. The relative complexity of its use has led to the abandonment of this technique. Coronarography allows an indirect approach to coronary thrombosis. Certain aspects are evocative such as: intraluminal filling defect, complete occlusion with upstream convexity, ulceration and eccentric type 2 Ambrose classification plaques. As a function of the clinical presentation, the coronarographic views allow a good specificity for the diagnosis of thrombus. The sensitivity is weak, however, compared to angioscopy. Endocoronary ultrasound does not allow identification of fresh thrombus which is not echogenic and does not allow differentiation between older thrombus and lipid plaque. In the future, magnetic resonance imaging could prove interesting in the detection of recent thrombus.

Angioscopy↗
PubMed2001

Patency of percutaneous transluminal coronary angioplasty sites at 6-month angiographic follow-up: A key determinant of survival in diabetics after coronary balloon angioplasty.

BACKGROUND: Several reports have demonstrated a high mortality rate in diabetic patients treated by standard coronary balloon angioplasty. No clear explanation has been provided for this finding. METHODS AND RESULTS: Consecutive diabetic patients successfully treated by standard coronary balloon angioplasty (n=604) were enrolled in a follow-up program including repeated angiography at 6 months and long-term clinical follow-up. Clinical follow-up was available in 603 patients (99.8%). Twelve patients died, 2 underwent bypass surgery before scheduled repeated angiography, and 76 declined angiography. Determinants of long-term mortality were analyzed in the 513 patients with angiography at 6 months and long-term clinical follow-up (mean follow-up, 6.5+/-2.4 years). On the basis of the results of repeated angiography, 3 groups of patients were defined: group 1, 162 patients without restenosis (32%); group 2, 257 patients with nonocclusive restenosis (50%); and group 3, 94 patients with coronary occlusion (18%). Overall actuarial 10-year mortality rate was 36%. Actuarial 10-year mortality was 24% in group 1, 35% in group 2, and 59% in group 3 (P:<0.0001). Multivariate analysis demonstrated that coronary occlusion was a strong and independent correlate of long-term total mortality (hazard ratio, 2.16; 95% CI, 1.43 to 3.26; P:=0.0003) and cardiac mortality (hazard ratio, 2.38; 95% CI, 1.48 to 3.85; P:=0.0004). CONCLUSIONS: This study demonstrates that restenosis, especially in its occlusive form, is a major determinant of long-term mortality in diabetic patients after coronary balloon angioplasty.

Aged↗
PubMed2000

A comparison of systematic stenting and conventional balloon angioplasty during primary percutaneous transluminal coronary angioplasty for acute myocardial infarction. STENTIM-2 Investigators.

OBJECTIVES: In a multicenter, randomized trial, systematic stenting using the Wiktor stent was compared to conventional balloon angioplasty with provisional stenting for the treatment of acute myocardial infarction (AMI). BACKGROUND: Primary angioplasty in AMI is limited by in-hospital recurrent ischemia and a high restenosis rate. METHODS: A total of 211 patients with AMI <12 h from symptom onset, with an occluded native coronary artery, were randomly assigned to systematic stenting (n = 101) or balloon angioplasty (n = 110). The primary end point was the binary six-month restenosis rate determined by core laboratory quantitative angiographic analysis. RESULTS: Angiographic success (Thrombolysis in Myocardial Infarction [TIMI] flow grade 3 and residual diameter stenosis <50%) was achieved in 86% of the patients in the stent group and in 82.7% of those in the balloon angioplasty group (p = 0.5). Compared with the 3% cross-over in the stent group, cross-over to stenting was required in 36.4% of patients in the balloon angioplasty group (p = 0.0001). Six-month binary restenosis (> or = 50% residual stenosis) rates were 25.3% in the stent group and 39.6% in the balloon angioplasty group (p = 0.04). At six months, the event-free survival rates were 81.2% in the stent group and 72.7% in the balloon angioplasty group (p = 0.14), and the repeat revascularization rates were 16.8% and 26.4%, respectively (p = 0.1). At one year, the event-free survival rates were 80.2% in the stent group and 71.8% in the balloon angioplasty group (p = 0.16), and the repeat revascularization rates were 17.8% and 28.2%, respectively (p = 0.1). CONCLUSIONS: In the setting of primary angioplasty for AMI, as compared with a strategy of conventional balloon angioplasty, systematic stenting using the Wiktor stent results in lower rates of angiographic restenosis.

Angioplasty, Balloon↗
PubMed2000

Effect of percutaneous adenovirus-mediated Gax gene delivery to the arterial wall in double-injured atheromatous stented rabbit iliac arteries.

Though the efficacy of intravascular gene transfer has been demonstrated in native vessels following acute injury, this methodology has not been validated in complex models of vascular injury that more closely mimic clinical angioplasty procedures. Previous studies have shown that Gax gene overexpression modulates the injury-induced remodeling of the vessel in rat carotid and normal rabbit iliac arteries. Here, we evaluated the effect of the Gax gene delivery in atheromatous stented vessels. Rabbits were fed 120 g daily of 1% cholesterol diet for 3 weeks. At 1 week they underwent initial injury on the external iliac artery, then balloon angioplasty was performed at 3 weeks at the same site with a 2.5 mm diameter channel balloon catheter (three times 1 min at 6 atm). Either saline (n = 4) or the control viral construct Ad-CMVluc (5 x 109 p.f.u.) (n = 5) or Ad-CMVGax (5 x 10(9) p.f.u.) (n = 4) was delivered with a poloxamer mixture via a channel balloon (6 atm, 30 min), and a 15 mm long Palmaz-Schatz stent (PS154) was then deployed at the site (1 min, 8 atm). Arteries were analyzed 1 month later. At 1 month, the Ad-CMVGax treated arteries exhibited a lower maximal intimal area (1. 15+/-0.1 mm2) than saline (1.87+/-0.15 mm2, P = 0.007) or Ad-CMVluc-treated vessels (1.98+/-0.31 mm2, P = 0.04). Likewise Ad-CMVGax-treated vessels displayed a lower maximal percentage cross-sectional area narrowing (35.1+/-3.5%) than saline (65.3+/-9.4%, P = 0.01) or Ad-CMVluc-treated vessels (62.7+/-6.7%, P = 0.02). Angiographic analysis revealed larger minimal lumen diameter in Ad-CMVGax treated arteries (2.0+/-0.1 mm) than saline (1.14+/-0.36 mm, P = 0.06) or Ad-CMVluc-treated vessels (1.23+/-0.25 mm, P = 0.02). Overexpression of the Gax gene inhibits neointimal hyperplasia and lumen loss in atheromatous stented rabbit iliac arteries.

Adenoviridae↗
PubMed1999

L-arginine and L-NAME have no effects on the reendothelialization process after arterial balloon injury.

OBJECTIVE: Growth regulatory properties of nitric oxide (NO) in cultured endothelial cells is controversial. The aim of our study was to investigate the effect of L-arginine, the endogenous NO precursor, and L-NAME, an inhibitor of NO synthase on the reendothelialization process after angioplasty. METHODS: Fifty-five New Zealand White rabbits underwent denudation of the left iliac artery. After injury the rabbits were randomized in three groups: L-arginine 2.25% (L-arginine, n = 19); NG-nitro-L-arginine methyl ester 15 mg/kg/day (L-NAME, n = 19); and placebo (controls, n = 17). Treatment was solubilized in drinking water. Reendothelialization was evaluated at 4 weeks by macroscopic evaluation of Evans blue staining and endothelial-specific immunostaining (CD-31) on cross sections. Intimal hyperplasia was evaluated by morphometric analysis. RESULTS: Despite a significant increase in plasma arginine (P = 0.001) and a reduction in intimal hyperplasia (P = 0.003) with L-arginine, neither agent had a significant effect on reendothelialization at 4 weeks (controls = 36 +/- 4%, L-arginine = 43 +/- 3%, L-NAME = 33 +/- 4%; NS). CONCLUSION: These results suggest that, in spite of previously demonstrated effects on neointimal hyperplasia, the NO pathway does not influence the regrowth of macrovascular endothelial cells in vivo.

Analysis of Variance↗
PubMed1999

Angiographically documented late reocclusion after successful coronary angioplasty of an infarct-related lesion is a powerful predictor of long-term mortality.

BACKGROUND: Late reocclusion of an infarct-related artery (IRA) that was patent in the early days after acute myocardial infarction (MI) is a frequent event; the reocclusion rate may be as high as 30%. Few studies have been designed to analyze the impact of late reocclusion of the IRA on late survival. METHODS AND RESULTS: We studied 528 patients who all had a patent IRA after a successful PTCA procedure 10+/-6 days after MI and who underwent systematic 6-month angiographic follow-up to assess late patency of the IRA. We compared long-term survival of patients with and without late reocclusion. Based on the results of 6-month follow-up angiography, 2 groups of patients were defined: (1) 90 patients (17%) with reocclusion (Thrombolysis In Myocardial Infarction [TIMI] flow 0 or 1) and (2) 438 patients (83%) without reocclusion. Long-term clinical follow-up was obtained for all 528 patients at a median of 5.7 years after follow-up angiography (6.4 years after PTCA). The overall actuarial 8-year total mortality rate was 13%. At the end of follow-up, there were 35 deaths (8%) among the 438 patients without reocclusion and 18 deaths (20%) among the 90 patients with reocclusion (P=0.002). The actuarial 8-year total mortality rate was 10% in patients without reocclusion and 28% in patients with reocclusion (P=0.0003). The actuarial cardiovascular mortality rate was 7% in patients without reocclusion and 25% in patients with reocclusion (P<0.0001). The impact of reocclusion on long-term mortality was greater in patients with anterior MI. CONCLUSIONS: Late IRA patency is strongly associated with long-term survival after MI. These observations should encourage prospective studies to evaluate the impact of strategies designed to prevent late reocclusion in postinfarction patients.

Adult↗
PubMed1999

Role of nitric oxide in restenosis after experimental balloon angioplasty in the hypercholesterolemic rabbit: effects on neointimal hyperplasia and vascular remodeling.

OBJECTIVES: The purpose of this study was to assess the effects of L-arginine and N(G)-nitro-L-arginine methyl ester (L-NAME) on neointimal hyperplasia and vascular remodeling after balloon angioplasty in the hypercholesterolemic rabbit. BACKGROUND: Restenosis after balloon angioplasty is a consequence of both neointimal hyperplasia and vessel remodeling. Nitric oxide inhibits neointimal hyperplasia, but its effect on vessel remodeling is unknown. METHODS: Six weeks after induction of bilateral iliac atherosclerosis, 48 rabbits underwent successful angioplasty in 75 vessels. Eight rabbits (acute group) were sacrificed immediately after angioplasty. The remaining animals received either placebo (chronic control group), or a diet supplemented with either L-arginine (1.5 g/kg/day), or L-NAME (15 mg/kg/day) for 4 weeks after angioplasty. RESULTS: The intimal area was significantly greater in the chronic control group compared to the acute group (2.60+/-1.03 mm2 vs. 1.35+/-0.62 mm2). This increase in intimal area was lower in the L-arginine group (1.79+/-0.61 mm2), and greater in the L-NAME group (3.23+/-0.92 mm2). The area circumscribed by the internal elastic lamina (IEL) increased significantly in the control group compared to the acute group (from 2.52+/-0.66 to 3.33+/-0.85 mm2); a more marked increase occurred in the L-NAME group (3.90+/-0.85 mm2). By contrast, IEL area was unchanged in the L-arginine group (2.41+/-0.62 mm2). As a result, there was no significant difference in lumen area after 4 weeks in the chronic groups (control: 0.74+/-0.38 mm2; L-arginine: 0.50+/-0.43 mm2; L-NAME: 0.48+/-0.42 mm2). CONCLUSIONS: Our results demonstrate that L-arginine inhibits whereas L-NAME stimulates neointimal hyperplasia after experimental balloon angioplasty in the hypercholesterolemic rabbit. However, the lack of vessel enlargement in the L-arginine group resulted in a similar final lumen size in the L-NAME and L-arginine groups.

Angiography↗
PubMed1999

Restenosis, late vessel occlusion and left ventricular function six months after balloon angioplasty in diabetic patients.

OBJECTIVES: We studied angiographic outcome and its predictors after traditional coronary balloon angioplasty in diabetics. We further examined whether changes in ejection fraction were influenced by the status of the dilated site(s) at follow-up. BACKGROUND: Recent studies have suggested that diabetics have a particularly poor outcome after balloon angioplasty. The reasons for this observation are not known. METHODS: We investigated procedural and six-month angiographic outcome, analyzed by quantitative coronary angiography, and left ventricular function in 485 consecutive diabetics (627 lesions) treated by balloon angioplasty without stent implantation. RESULTS: The procedure was successful in 455 (94%) patients; angiographic follow-up was available in 377 patients (83%). At follow-up, the rates of restenosis and total occlusion were 62% and 13%, respectively. Five independent predictors of restenosis were identified: the presence of organ damage, a saphenous vein graft (SVG) angioplasty, a bifurcation lesion, a Thrombolysis in Myocardial Infarction (TIMI) flow <3 preprocedure and the degree of residual stenosis. Four independent predictors of vessel occlusion were identified: treatment with insulin, a SVG angioplasty, a TIMI flow <3 preprocedure and the degree of residual stenosis after angioplasty. Late vessel occlusion at angioplasty site(s) was observed in 15% of patients, ranging from 11% for a one-site procedure to 37% for a three-site procedure. This complication was associated with a decrease in ejection fraction at follow-up (-6.2 +/- 9.9%, p = 0.0001), whereas no significant change was observed in patients without occlusion. CONCLUSIONS: This study shows that late vessel occlusion is a frequent mode of restenosis in diabetic patients and is associated with a significant decrease in ejection fraction. This could partly explain the poor long-term clinical outcome reported in such patients after traditional balloon angioplasty.

Angioplasty, Balloon, Coronary↗
PubMed1999

Growth factors and endothelial dysfunction.

Endothelial dysfunction has been implicated in the pathogenesis of many cardiovascular diseases: experimental and clinical studies have shown that endothelial dysfunction may be a key factor in various processes, including abnormal arterial vasomotion, thrombosis or neointimial proliferation. Endothelial dysfunction has been shown to be a characteristic feature of atherosclerotic vessels, sites subject to mechanical injury or collateral vessels that develop in response to severe ischaemia. Fibroblast growth factor (FGF) and vascular endothelial growth factor (VEGF) are important growth factors for endothelial cells in vitro. While VEGF is specific for endothelial cells. FGFs are also potent growth factors for other cell types such as smooth muscle cells. Recent studies have demonstrated the feasibility of using endothelial cell growth factors in vivo. Basic FGF (bFGF) and VEGF have been shown to increase the development of collateral vessels in ischaemic models and to enhance the extent of endothelial regrowth following arterial injury. The marked anatomical improvement associated with the administration of endothelial cell growth factors has promoted questions concerning a possible role for these factors in endothelial dysfunction. In vivo administration of endothelial cell growth factors is associated with significant improvement in endothelium-dependent responses. This effect is observed with bFGF and VEGF in various animal models of endothelial dysfunction such as the collateral circulation, the regenerated endothelium following arterial injury and experimental atherosclerosis. While the precise mechanisms underlying this ubiquitous beneficial effect of endothelial cell growth factors are still to be determined, these results do support the concept of using such factors as a new therapeutic strategy in patients with vascular diseases.

Animals↗
PubMed1999

Growth factors and endothelial dysfunction.

Endothelial dysfunction has been implicated in the pathogenesis of many cardiovascular diseases; experimental and clinical studies have shown that endothelial dysfunction may be a key factor in various processes, including abnormal arterial vasomotion, thrombosis or neointimal proliferation. Endothelial dysfunction has been shown to be a characteristic feature of atherosclerotic vessels, sites subject to mechanical injury or collateral vessels that develop in response to severe ischaemia. Fibroblast growth factor (FGF) and vascular endothelial growth factor (VEGF) are important growth factors for endothelial cells in vitro. While VEGF is specific for endothelial cells, FGFs are also potent growth factors for other cell types such as smooth muscle cells. Recent studies have demonstrated the feasibility of using endothelial cell growth factors in vivo. Basic FGF (bFGF) and VEGF have been shown to increase the development of collateral vessels in ischaemic models and to enhance the extent of endothelial regrowth following arterial injury. The marked anatomical improvement associated with the administration of endothelial cell growth factors has promoted questions concerning a possible role for these factors in endothelial dysfunction. In vivo administration of endothelial cell growth factors is associated with significant improvement in endothelium-dependent responses. This effect is observed with bFGF and VEGF in various animal models of endothelial dysfunction such as the collateral circulation, the regenerated endothelium following arterial injury and experimental atherosclerosis. While the precise mechanisms underlying this ubiquitous beneficial effect of endothelial cell growth factors are still to be determined, these results do support the concept of using such factors as a new therapeutic strategy in patients with vascular diseases.

Animals↗