Platelet glycoprotein IIb/IIIa inhibition with coronary stenting for acute myocardial infarction

BACKGROUND

When administered in conjunction with primary coronary stenting for the treatment of acute myocardial infarction, a platelet glycoprotein IIb/IIIa inhibitor may provide additional clinical benefit, but data on this combination therapy are limited.

METHODS

We randomly assigned 300 patients with acute myocardial infarction in a double-blind fashion either to abciximab plus stenting (149 patients) or placebo plus stenting (151 patients) before they underwent coronary angiography. Clinical outcomes were evaluated 30 days and 6 months after the procedure. The angiographic patency of the infarct-related vessel and the left ventricular ejection fraction were evaluated at 24 hours and 6 months.

RESULTS

At 30 days, the primary end point--a composite of death, reinfarction, or urgent revascularization of the target vessel--had occurred in 6.0 percent of the patients in the abciximab group, as compared with 14.6 percent of those in the placebo group (P=0.01); at 6 months, the corresponding figures were 7.4 percent and 15.9 percent (P=0.02). The better clinical outcomes in the abciximab group were related to the greater frequency of grade 3 coronary flow (according to the classification of the Thrombolysis in Myocardial Infarction trial) in this group than in the placebo group before the procedure (16.8 percent vs. 5.4 percent, P=0.01), immediately afterward (95.1 percent vs. 86.7 percent, P=0.04), and six months afterward (94.3 percent vs. 82.8 percent, P=0.04). One major bleeding event occurred in the abciximab group (0.7 percent); none occurred in the placebo group.

CONCLUSIONS

As compared with placebo, early administration of abciximab in patients with acute myocardial infarction improves coronary patency before stenting, the success rate of the stenting procedure, the rate of coronary patency at six months, left ventricular function, and clinical outcomes.

Evidence for the rapid onset of apoptosis in medial smooth muscle cells after balloon injury

BACKGROUND

Vascular myocyte apoptotic cell death has been reported in human atherectomy and endarterectomy specimens and for neointimal smooth muscle cells (SMCs) in balloon-injured rat carotid arteries between 7 and 30 days after injury. However, the immediate effect of balloon injury on medial SMC viability has not been examined.

METHODS AND RESULTS

Rat carotid arteries were harvested at the time of balloon injury (T = 0) and at 0.5, 1, 2, and 4 hours after injury. Uninjured vessels or vessels harvested at the time of injury (T = 0) did not display evidence of apoptosis. However, as early as 30 minutes after injury, 70% of medial SMCs appeared apoptotic by TdT-mediated dUTP nick end labeling (TUNEL) analysis and by the appearance of condensed chromatin. High frequencies of TUNEL-positive cells were also observed at 1 and 2 hours after injury but not at 4 hours. Transmission electron microscopy revealed many cells with morphological characteristics of apoptosis in the injured sections. A marked decrease in bcl-X expression was detected in the most luminal layers of the media. To corroborate these findings in a second animal model, rabbit external iliac arteries were analyzed after balloon angioplasty. Apoptotic cell death was evident in rabbit arteries at 30 minutes and at 4 hours after injury.

CONCLUSIONS

As early as 30 minutes after balloon injury, myocytes appear to undergo apoptotic cell death at a high frequency as shown by TUNEL staining, chromatin condensation, and the appearance of morphological features in electron micrographs. The induction of apoptosis coincides with a marked downregulation of bcl-X expression.

Passivation of metallic stents after arterial gene transfer of phVEGF165 inhibits thrombus formation and intimal thickening

OBJECTIVES

This study sought to test the hypothesis that direct gene transfer of an endothelial cell mitogen could passivate metallic stents by accelerating endothelialization of the prosthesis.

BACKGROUND

Thrombosis and restenosis comprise the principal clinical manifestations of compromised biocompatibility of endovascular stents. Previous studies have demonstrated that endothelial recovery at sites of balloon injury is a critical determinant of consequent intimal thickening and mural thrombus. We therefore investigated the potential for an endothelial cell mitogen delivered as plasmid DNA to optimize stent biocompatibility.

METHODS

Naked plasmid DNA encoding vascular endothelial growth factor (VEGF)/vascular permeability factor (VPF) (phVEGF165) was delivered locally using a hydrogel-coated balloon angioplasty catheter to 16 rabbit iliac arteries in which metallic stents had been placed at the site of balloon injury; the contralateral iliac artery of each rabbit was balloon injured and stented but not transfected.

RESULTS

Stent endothelialization was accelerated by phVEGF165 gene transfer (87.38 +/- 5.06% vs. 33.13 +/- 9.73% [mean +/- SEM] of the planimetered stent surface in the treated vs. contralateral limb, p = 0.005). This was associated with a significant reduction in mural thrombus (3.7 +/- 2.4% vs. 32.7 +/- 9.7%, p = 0.01) at day 7 and intimal thickening (maximal intimal area 0.61 +/- 0.09 vs. 1.44 +/- 0.12 mm2, p < 0.0001) at day 28. No benefit was observed from pCMV-luciferase in 14 similarly instrumented control rabbits.

CONCLUSIONS

These findings indicate that arterial gene transfer of naked plasmid DNA encoding for an endothelial cell mitogen may successfully passivate endovascular stents by accelerating stent endothelialization, thereby reducing in-stent thrombus and obstruction due to intimal thickening.

Stent endothelialization. Time course, impact of local catheter delivery, feasibility of recombinant protein administration, and response to cytokine expedition

BACKGROUND

Because prior studies have established the critical role of the endothelium in preventing vascular thrombosis and intimal thickening, we designed a series of experiments to determine the feasibility of percutaneous local catheter delivery of recombinant protein to accelerate development of an intact endothelial monolayer after stent implantation.

METHODS AND RESULTS

Balloon injury followed by percutaneous delivery of a 15-mm-long, balloon-expandable metallic stent was performed in 64 rabbit external iliac arteries (baseline diameter, 2.67 +/- 0.07 mm). Planimetric time-course analysis disclosed < 20% stent endothelialization at 4 days, < 40% at 7 days, and near-complete endothelialization at 28 days. The reporter protein horseradish peroxidase and the endothelial cell-specific recombinant protein vascular endothelial growth factor (VEGF) were each effectively delivered from a local delivery catheter (channel balloon catheter, ChB) after stent implantation. Although local catheter delivery (of vehicle control) itself mildly retarded the extent of stent endothelialization (10.6 +/- 2.9%) versus no local delivery (25.5 +/- 6.6%, P = .045), local ChB delivery of 100 micrograms VEGF overcame this catheter effect: By day 7, stent endothelialization was nearly complete (91.8 +/- 3.8%) (P < .0001 versus no local delivery). Consequently, stent thrombus was reduced in the VEGF-treated group (mural thrombus, 5.3 +/- 3.7%) versus no local delivery (29.3 +/- 6.8%, P = .006). Occlusive thrombus was seen only in the absence of local VEGF administration.

CONCLUSIONS

(1) Local delivery of recombinant protein to the arterial wall is feasible after stent implantation, and (2) local delivery of the endothelial cell mitogen VEGF accelerates stent endothelialization, reducing stent thrombosis. These results thus establish a novel means by which the safety and/or bioactivity of endovascular stents may be further enhanced.

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.

Relationship between post-treatment platelet reactivity and ischemic and bleeding events at 1-year follow-up in patients receiving prasugrel

BACKGROUND

Post-treatment platelet reactivity (PR) is associated with ischemic and bleeding events in patients receiving P2Y12 receptor antagonists.

OBJECTIVES

We aimed to study the relationship between post-treatment PR after a 60-mg loading dose (LD) of prasugrel and 1-year thrombotic and bleeding events.

METHOD

Patients were prospectively included in this multicenter study if they had a successful percutaneous coronary intervention (PCI) for acute coronary syndrome (ACS) and received prasugrel. The platelet reactivity index (PRI) was measured using the Vasodilator-Stimulated Phosphoprotein index (VASP) after a prasugrel LD. Endpoints included the rate of thrombotic events and bleeding events at 1 year.

RESULTS

Among the 301 patients enrolled, 9 (3%) were lost to follow-up at 1 year. The rates of thrombotic and bleeding events at 1 year were of 7.5% and 6.8%, respectively. Receiver-operating curve (ROC) analysis demonstrated an optimal cut-off value of 53.5% of PRI to predict thrombotic events at 1 year. Using this cut-off value we observed that patients exhibiting high on-treatment platelet reactivity (HTPR) had a higher rate of thrombotic events (22.4% vs. 2.9%; P < 0.001). In parallel the optimal cut-off value of PRI to predict bleeding was 16%. Patients with a PRI ≤ 16% had a higher rate of bleeding events compared with those with a PRI > 16% (15.6% vs. 3.3%; P < 0.001). In multivariate analysis, the PRI predicted both thrombotic and bleeding events (OR: 1.44, 95% confidence interval [CI]: 1.2-1.72; P < 0.001 and OR: 0.75, 95% CI: 0.59-0.96; P = 0.024 [respectively, per 10% increase]).

CONCLUSION

Platelet reactivity measurement after a prasugrel LD predicts both ischemic and bleeding events at 1 year follow-up for ACS patients undergoing PCI.

Focal electrical intracerebral stimulation of a face-sensitive area causes transient prosopagnosia

Face perception is subtended by a large set of areas in the human ventral occipito-temporal cortex. However, the role of these areas and their importance for face recognition remain largely unclear. Here we report a case of transient selective impairment in face recognition (prosopagnosia) induced by focal electrical intracerebral stimulation of the right inferior occipital gyrus. This area presents with typical face-sensitivity as evidenced by functional neuroimaging right occipital face area (OFA). A face-sensitive intracerebral N170 was also recorded in this area, supporting its contribution as a source of the well-known N170 component typically recorded on the scalp. Altogether, these observations indicate that face recognition can be selectively impaired by local disruption of a single face-sensitive area of the network subtending this function, the right OFA.

Stent placement compared with balloon angioplasty for small coronary arteries: in-hospital and 6-month clinical and angiographic results

BACKGROUND

Stenting has been demonstrated to be superior to balloon angioplasty in de novo focal lesions located in large native vessels. However, in small vessels, the benefit of stenting remains questionable.

METHODS AND RESULTS

A total of 381 symptomatic patients with de novo focal lesion located on a small coronary segment vessel (<3 mm) were randomly assigned to either stent implantation (192 patients; 197 lesions) or standard balloon angioplasty (189 patients; 198 lesions). The primary end point was the angiographic restenosis rate at 6 months, as determined by quantitative coronary angiography. On intention-to-treat analysis, angiographic success rate and major adverse cardiac events were comparable: 97.9% and 4.6% versus 93.9% and 5.8% in the stent group and the balloon group, respectively. After the procedure, a larger acute gain was achieved with stent placement (1.35+/-0.45 versus 0.94+/-0.47 mm, P=0.0001), resulting in a larger minimal lumen diameter (2.06+/-0.42 versus 1.70+/-0.46 mm, P=0.0001). At follow-up (obtained in 91% of patients), angiographic restenosis rate was 21% in the stent group versus 47% in the balloon group (P=0.0001), a risk reduction of 55%. Repeat target lesion revascularization was less frequent in the stent group (13% versus 25%, P=0.0006).

CONCLUSIONS

Elective stent placement in small coronary arteries with focal de novo lesions is safe and associated with a marked reduction in restenosis rate and subsequent target lesion revascularization rate at 6 months.

Anticoagulant (fluindione)-aspirin combination in patients with high-risk atrial fibrillation. A randomized trial (Fluindione, Fibrillation Auriculaire, Aspirin et Contraste Spontané; FFAACS)

BACKGROUND

A combination of low-dose aspirin with anticoagulants may provide better protection against thromboembolic events compared to anticoagulants alone in high-risk patients with atrial fibrillation.

OBJECTIVE

Evaluation of the preventive efficacy against nonfatal thromboembolic events and vascular deaths of the combination of the oral anticoagulant fluindione and aspirin (100 mg) in patients with high-risk atrial fibrillation.

METHODS

A multicenter, placebo-controlled, double-blind, randomized trial was conducted at 49 investigating centers in France. Atrial fibrillation patients with a previous thromboembolic event or older than 65 years and with either a history of hypertension, a recent episode of heart failure or decreased left ventricular function were included in the study. Patients were treated with fluindione plus placebo (i.e. anticoagulant alone) or fluindione plus aspirin (i.e. combination therapy), with an international normalized ratio target of between 2 and 2.6. The combined primary endpoint was stroke (ischemic or hemorrhagic), myocardial infarction, systemic arterial emboli or vascular death. The secondary endpoint was the incidence of hemorrhagic complications.

RESULTS

The 157 participants (average age 74 years; 52% women; 42% with paroxysmal atrial fibrillation) were followed for an average of 0.84 years. Three nonfatal thromboembolic events were observed (1 in the anticoagulation group, 2 in the combination group) and 6 patients died (3 in the anticoagulation group, 3 in the combination group), none of them from a thromboembolic complication. However, 3 deaths were secondary to severe hemorrhagic complications (1 in the anticoagulation group, 2 in the combination group). Nonfatal hemorrhagic complications occurred more often in the combination group (n = 10, 13.1%) compared to the anticoagulation group (n = 1, 1.2%) (p = 0.003).

CONCLUSION

The combination of aspirin with anticoagulant is associated with increased bleeding in elderly atrial fibrillation patients. The effect on thromboembolism and the overall balance of benefit to risk could not be accurately assessed in this study due to the limited number of ischemic events.

Accelerated endothelialization by local delivery of recombinant human vascular endothelial growth factor reduces in-stent intimal formation

Endothelium plays an important role in vascular smooth muscle cell proliferation and thrombus deposition. We thus hypothesized that local delivery of recombinant human vascular endothelial growth factor (rhVEGF) might reduce in-stent intimal formation. Balloon injury followed by Palmaz-Schatz stent implantation was performed in the external iliac artery of 30 New Zealand rabbits. Animals were then randomized to: 1) no local delivery (Control group, n=10); 2) local delivery via a channel balloon catheter of 100 microg rhVEGF165 (VEGF group, n=10); or 3) local delivery of the vehicle solution (Vehicle group, n=10). Animals were sacrificed 28 days later and morphometric analysis was performed. Maximal intimal area was reduced from 1.47+/-0.12 mm2 and 1.44+/-0.10 mm2 in the Control and Vehicle groups, respectively, to 0.87+/-0.06 mm2 in the VEGF group (p<.001). Accelerated endothelialization by local delivery of an endothelial-specific growth factor, rhVEGF, significantly reduces in-stent intimal formation and could constitute an attractive alternative to direct antiproliferative strategies.

Bilateral subthalamic nucleus stimulation improves balance control in Parkinson's disease

BACKGROUND

Parkinson's disease (PD), the most common basal ganglia degenerative disease, affects balance control, especially when patients change balance strategy during postural tasks. Bilateral chronic stimulation of the subthalamic nucleus (STN) is therapeutically useful in advanced PD, and reduces the motor signs of patients. Nevertheless, the effects of STN stimulation on postural control are still debatable.

AIMS

To assess the impact of bilateral STN stimulation on balance control in PD and to determine how basal ganglia related sensorimotor modifications act on neurosensorial organisation of balance and motor postural programming.

METHODS

Twelve subjects aged 45-70 years underwent unified Parkinson's disease rating scale motor (part III) clinical tests, static and dynamic posturography, including sensory organisation and adaptation tests, shortly before and six months after bilateral implantation of electrodes into the STN.

RESULTS

The postoperative static test showed an improvement in postural control precision both in eyes open and eyes closed conditions. The dynamic test highlighted the decreased number of falls and the ability of the patients to develop more appropriate sensorimotor strategies when stimulated. The sensory organisation test showed an improvement of equilibrium score and, thus, a better resolution of sensorial conflicts.

CONCLUSIONS

STN stimulation allowed a reduction in rigidity and therefore an improvement in the ability to use muscular proprioception as reliable information, resulting in vestibulo-proprioceptive conflict suppression. STN stimulation has a synergistic effect with levodopa for postural control. Accordingly, non-dopaminergic pathways could be involved in postural regulation and STN stimulation may influence the functioning of these pathways.

Mapping the basal ganglia: fMRI evidence for somatotopic representation of face, hand, and foot

OBJECTIVE

To noninvasively investigate the somatotopy of the basal ganglia in humans.

METHODS

Functional MRI, 1.5-T, was performed on six normal right-handed volunteers during simple acoustically paced motor tasks involving the right hand, foot, and face.

RESULTS

In a single-subject analysis, statistical parametric maps showed overlapping activation extending along the anteroposterior extent of the left lentiform nucleus (LLN) for the hand, foot, and face representations. Within the LLN, the centers of gravity of each body part, reflecting both the extent and gradient of activation, were all located in the retrocommissural portion of the putamen. Their spatial relationship followed a similar pattern across subjects-face was medial to toes and fingers, toes were dorsal and rostral to fingers.

CONCLUSIONS

The somatotopic organization of hand, face, and foot representation in the human lentiform nucleus suggests a triangular pattern, rather than the linear pattern seen in primate studies. The overlap observed between the distinct body parts differs from the cortical sensorimotor representation, indicating a different organizational concept of the basal ganglia.

Spatial localization of EEG electrodes

AIM OF THE STUDY

An important goal for EEG-based functional brain studies is to estimate the location of brain sources that produce the scalp-recorded signals. Such source localization requires locating precisely the position of the EEG sensors. This review describes and compares different methods that are used for localizing EEG sensors.

RESULTS

Five different methods have been described in literature. Manual methods consist in manual measurements to calculate the 3D coordinates of the sensors. Electromagnetic and ultrasound digitization permit localization by using trade devices. The photogrammetry system consists in taking pictures of the patient's head with the sensors. The last method consists in directly localizing the EEG sensors in the MRI volume.

DISCUSSION AND CONCLUSIONS

The spatial localization of EEG sensors is an important step in performing source localization. This method should be accurate, fast, reproducible, and cheap. Currently, electromagnetic digitization is the most currently used method but MRI localization could be an interesting way because no additional method or device needs to be used to locate the EEG sensors.

Percutaneous delivery of the gax gene inhibits vessel stenosis in a rabbit model of balloon angioplasty

OBJECTIVES

The expression of gax, an anti-proliferative homeobox gene, is rapidly downregulated in vascular smooth muscle cells (VSMCs) following arterial injury. Here we performed percutaneous adenovirus-mediated gene transfer into the iliac arteries of normal rabbits using a channel balloon catheter to assess the effects of gax overexpression on neointima formation, lumen diameter, reendothelialization and functional vasomotion.

METHODS

A channel balloon catheter was used to perform both the arterial injury and local gene delivery. In each animal both iliac arteries were randomly assigned to receive either an adenovirus expressing the gax gene (Ad-Gax) or the beta-galactosidase gene (Ad-beta gal). In a second group of animals arteries were randomly assigned to receive either Ad-beta gal or saline.

RESULTS

At one month, angiography revealed 36% less luminal narrowing in the Ad-Gax-treated arteries relative to the Ad-beta gal-treated control arteries. Histological analysis revealed that the intimal/medial ratio (I/M) was reduced by 56% in the Ad-Gax group. Endothelium-dependent vasomotion was not affected by the gax gene transfer. In the second group, no statistically significant differences were found between the saline and the Ad-beta gal-treated vessels for any of these parameters.

CONCLUSIONS

Percutaneous adenovirus delivery of the gax gene to rabbit iliac arteries following endothelial denudation and vessel wall injury reduces neointimal hyperplasia and luminal stenosis, but does not affect endothelium-dependent vasomotion. This study demonstrates that a VSMC transcription factor can potentially be utilized for the development of a molecular therapy for vascular disorders.

Psychogenic nonepileptic seizures: characterization of two distinct patient profiles on the basis of trauma history

This prospective study investigated and compared psychiatric features of 25 consecutive patients with psychogenic nonepileptic seizures (PNES) on the basis of presence of reported trauma. The "trauma" group comprised 19 patients (76%) and the "no-trauma" group comprised 6 patients (34%). We compared history of PNES, psychiatric comorbidity, alexithymia, and symptoms of dissociation. The study clearly characterized two distinct profiles of patients with PNES on the basis of trauma history. Patients with trauma had at least one psychiatric comorbidity or antecedent (vs 0% in the no-trauma group NT, P<0.001) and a higher median score of dissociation (P<0.001). Patients without trauma had more frequent "frustration situations" as a factor triggering PNES and subsequent sick leaves as perpetuating factors (P=0.001). Trauma antecedents correlated with a high rate of psychiatric comorbidity and a strong dissociative mechanism. Patients without trauma had no psychiatric comorbidity and a weaker dissociative mechanism.

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.

Randomised comparison of coronary stenting with and without balloon predilatation in selected patients

BACKGROUND

The SWIBAP (stent without balloon predilatation) prospective randomised trial was designed to compare direct coronary stenting with stenting preceded by lesion predilatation with an angioplasty balloon.

OBJECTIVE

To determine the feasibility and safety of direct stenting in non-complex coronary lesions in a prospective study.

PATIENTS AND DESIGN

All patients < 76 years of age scheduled to undergo angioplasty of a non-complex, non-calcified lesion in a coronary artery of > 3.0 mm, who granted their informed consent, were randomised into the trial. In group I, the stent was placed without balloon predilatation, while in group II stent implantation was preceded by balloon predilatation. The primary end point was the angiographic result according to procedure assigned by randomisation. An intravascular ultrasound substudy was performed in 60 patients.

RESULTS

Stent implantation was successful without predilatation in 192 of the 197 group I patients (97.5%), and with predilatation in 197 of the 199 group II patients (99%) (NS). No in-hospital stent thrombosis or death occurred. Overall procedural times, fluoroscopy times, and volumes of contrast agent given (mean (SD)) in group I v group II were 23.50 (13.54) min v 27.96 (15.23) min (p = 0.002), 6.04 (4.13) min v 6.67 (3.65) min (NS), and 135 (65) ml v 157 (62) ml (p < 0.001), respectively. No major adverse cardiovascular events had occurred by 30 days.

CONCLUSIONS

The feasibility and safety of direct stenting of selected and non-complex coronary lesions is confirmed. This technique was as successful as the conventional approach and was associated with a minor reduction in fluoroscopic exposure and procedure time and the administration of less contrast agent.

Early versus late coronary stenting following acute myocardial infarction: results of the STENTIM I Study (French Registry of Stenting in Acute Myocardial Infarction)

This study was undertaken to determine the feasibility and safety of coronary stenting in acute myocardial infarction (AMI). In AMI, primary percutaneous transluminal coronary angioplasty (PTCA) is accepted as the preferred method of reperfusion for patients presenting at highly experienced centres. Until recently, however, stenting has been avoided during AMI because of a potential high risk of thrombosis. This prospective observational study carried out in 20 centres and included 648 consecutive patients who underwent PTCA with stent implantation for AMI. Of these 648 patients, 269 (41.5%, Group 1) were dilated early (< 24 hr) after the onset of the symptoms (75% treated by direct PTCA) and 379 (58.5%, Group 2) were dilated between 24 hr and 14 days after AMI. Combined therapy with ticlopidin and aspirin was used after the procedure. Bailout stenting occurred more often in Group 1 than in Group 2 (17% vs. 9.5%)(P < 0.05). Angiographic successful stenting was similar in both groups of patients (96% vs. 97%). During the hospital follow-up period, stent thrombosis occurred in eight patients (3%) in Group 1 and in six patients (1.6%) in Group 2 (NS). There was 14 deaths (5.2%) in Group 1 and 11 deaths (3.9%) in Group 2 (NS). After multivariate analysis bailout stenting was identified as the sole predictor of stent thrombosis (P < 0.0001). Vascular access-site complications occurred in six patients (1%) with no difference between the two groups. This study indicates that patients who receive a coronary stent in AMI can be managed safely with antiplatelet therapy. Randomized studies are needed to determine the precise indication for coronary stenting as an adjunct to primary PTCA.

Effects of poloxamer 407 on transfection time and percutaneous adenovirus-mediated gene transfer in native and stented vessels

Reduction in transfection time and the ability to perform gene transfer in conjunction with endovascular stent implantation constitute two important challenges for percutaneous adenovirus-mediated gene transfer to vessel walls. Studies have suggested that the use of biocompatible polyol poloxamer 407 could be useful. We first evaluated the use of poloxamer 407 for percutaneous gene transfer in nonstented rabbit iliac arteries. A 200-microl mixture of Ad-RSVbetagal or Ad-CMVLuc in either phosphate-buffered saline (PBS) or 20% poloxamer was delivered. After 3 days, gene transfection was evaluated by X-Gal staining or measurement of luciferase activity. Poloxamer use resulted in a 3- to 15-fold increase in the percentage of transfected cells (X-Gal, p = 0.001) and a 16-fold increase in protein product (luciferase activity, p = 0.03), and allowed a decrease in transfection time from 30 to 5 min with minimal reduction in transfection efficiency. We then evaluated the feasibility of percutaneous gene transfer, using Ad-RSVbetagal diluted in pure PBS or 20% poloxamer, in conjunction with stent implantation. Gene delivery was performed either immediately before (pre-) or after (post-) stent implantation. When adenoviruses were diluted in PBS, gene transfer had a low efficiency (prestent, 0.3%; poststent, 0.2%; NS). With poloxamer, the efficacy was much higher (p = 0.0001) and similar "pre" (2.2%) or "post" (1.7%) stent delivery (NS).

CONCLUSIONS

(1) The use of poloxamer, rather than PBS, as a vehicle increases the efficacy of percutaneous adenovirus-mediated gene transfer and reduces transfection time; (2) gene transfer performed during stent implantation with poloxamer is feasible and achieves a significant level of gene expression. Thus percutaneous gene delivery is applicable to conventional stents and could present an attractive method by which to achieve local biological effects in a stent environment.

Early cell loss after angioplasty results in a disproportionate decrease in percutaneous gene transfer to the vessel wall

Acute cell loss has been documented following angioplasty of normal rat and rabbit arteries. Here we analyzed the effects of balloon injury intensity on early cellular loss in single- and double-injury models and how it influences the efficiency of percutaneous gene delivery to the vessel wall. Rabbits underwent bilateral iliac angioplasties (n = 52) with 2.5-mm (balloon-to-artery [B/A] ratio, 1.08 to 1.13) and 3.0-mm (B/A ratio, 1.29 to 1.34) balloons. In the single-injury model, the 3.0-mm balloon induced a 61% reduction in medial cellularity at 3 days postinjury (p < 0.001) while the 2.5-mm balloon did not produce significant cell loss. In the double-injury model, the effects were more pronounced, with 35% (p < 0.01) and 91% (p < 0.001) reductions in medial cellularity at 3 days with the 2.5- and 3.0-mm balloons, respectively, but neointimal cellularity was decreased only with the 3.0-mm balloon (37% reduction, p = 0.025). Adenovirus-mediated beta-galactosidase gene delivery with a channel balloon (n = 24) revealed that larger balloon-to-artery ratios decreased both absolute levels and relative frequencies of transgene expression in the vessel wall. In the single-injury model, gene transfer efficiency was 4.2+/-1.1 and 1.3+/-0.25% (p < 0.05) for the small and large balloons, respectively. In the double-injury model, gene transfer efficiency was 6.6+/-1.6 and 2.3+/-0.8% (p < 0.05) in the neointima and 4.1+/-1.2 and 2.6+/-1.2% (p = NS) in the media for the small and large balloon, respectively. We conclude that early cell loss is dependent on the intensity of the injury in both single- and double-injury models of balloon angioplasty, with greater frequencies of cell loss occurring in the media than in the neointima. In both models, larger balloon-to-artery ratios result in disproportionate reductions in percutaneous adenovirus-mediated gene delivery.