Abciximab and percutaneous coronary intervention: new indications. Medium-term benefit

(1) Abciximab is now indicated for the prevention of ischaemic complications in patients undergoing percutaneous coronary intervention, and for the prevention of myocardial infarction in patients with unstable angina undergoing percutaneous coronary intervention. (2) The clinical file on abciximab now includes three placebo-controlled trials. (3) The EPIC trial involved patients at high risk of thrombosis, while the EPILOG trial included patients regardless of their risk of thrombosis. In neither trial did abciximab reduce overall mortality. In high-risk patients abciximab reduced the risk of a new myocardial infarction at one year, but not for longer. In patients at lower risk, the reduction in the risk of reinfarction persisted for at least six months. (4) The CAPTURE trial showed that abciximab, started 24 hours before angioplasty for unstable angina, reduced the risk of myocardial infarction at one month. (5) The bleeding risk was controlled by the use of heparin at doses adjusted to body weight, and by applying strict precautions to protect the injection site.

Aorto-coronary dissection during angioplasty in a patient with myxedema

A 67-year-old man with overt hypothyroidism and medically controlled hypertension was admitted for coronary angiography because of exertional angina. His triiodothyronine (T3) and thyroxine (T4) levels had been low for 4 years. Although signs and symptoms of hypothyroidism were apparent, his hypercholesterolemia was mild. Coronary angiography revealed an eccentric stenosis in the distal portion of the right coronary artery and it was decided to perform angioplasty because his angina had continued in spite of medication. The dissection appeared at the lesion site after the first nominal inflation, and a subsequent image disclosed a spiral dissection from the dilated site to the aortic sinus and peripheral coronary artery. Although emergency stenting could not prevent the extension near the origin of the brachiocephalic artery, the false lumen thrombosed and then diminished with conservative therapy. Aorto-coronary dissection is potentially life-threatening and has been recently reported as a complication during cardiac catheterization procedures. Chronic hypothyroid insufficiency may be one of the risk factors for this complication.

A fifteen-year experience with carotid endarterectomy after a formal operative protocol requiring highly frequent patch angioplasty

PURPOSE

The early and late outcomes of carotid endarterectomy (CEA) following a rigid protocol of patch angioplasty or occasionally interposition bypass grafting, when the arteriotomy required to obtain a complete internal carotid end point extended distal to the bulb segment, and primary closure, when it was limited to the bulb, were studied.

METHODS

From November 1983 to August 1998, 1360 consecutive primary CEAs were performed on 1133 patients (621 men, 512 women), with a mean age of 67 years. Of these patients, 3.8% (51) had primary closure, 66.4% (903) had greater saphenous vein patch angioplasty, 28.4% (386) had synthetic (359 Dacron, 27 polytetrafluoroethylene) patch angioplasty, and 1.4% (20) had vein interposition bypass grafting procedures. Indications were transient ischemic attack in 34.7% of patients (472), stroke in 16.6% of patients (226), nonlateralizing symptoms in 10.9% of patients (148), and asymptomatic stenosis 70% or greater in 37.8% of patients (514). The mean follow-up period was 4.6 years.

RESULTS

The 30-day mortality rate was 1.0% (13 patients; 11 cardiac-related deaths, 2 strokes). The 30-day stroke rate was 1.3% (18 patients; 13 ipsilateral strokes, 5 major, 8 minor). The combined 30-day stroke and death rate was 2.1%. Four of the strokes (1 death) were caused by the hyperperfusion syndrome. The 30-day ipsilateral major stroke or mortality rate was 1.2% (16 patients). The 30-day rate of ipsilateral major stroke or death from stroke was 0.4% (5 patients). There were two synthetic and one vein patch internal carotid occlusions in 30 days. Synthetic-patched CEAs were predicted by means of Cox proportional hazards analysis to have higher risk ratios than saphenous vein-patched CEAs for early and late stroke (1. 3; 95% CI, 1.7 to 1.0; P =.04), for 50% or greater restenosis (2.4; 95% CI, 3.4 to 1.6; P <.001), and for 70% or greater restenosis (2. 5; 95% CI, 3.6 to 1.7; P <.001). The cumulative mortality rate (Kaplan-Meier) was 13% at 5 years and 31% at 10 years. The cumulative stroke rate was 7% at 5 years and 14% at 10 years. The 50% or greater restenosis rate was higher in women than in men at 5 years (9% versus 5%; P =.02, Wilcoxon), but tended to equalize later. The 50% or greater restenosis rate was higher in synthetic-patched CEAs than in saphenous vein-patched CEAs (12% versus 1% at 1 year; 17% versus 3% at 4 years; and 24% versus 10% at 8 years; P <.001 by means of log-rank and Wilcoxon). Restenosis after 5 years was more frequently located in the distal common carotid artery (13 of 20 cases). Late reoperations were more frequent and occurred earlier in synthetic-patched CEAs (eight cases at a mean of 1.6 years) than vein-patched CEAs (14 cases at a mean of 6.9 years; P =.01). No strokes and one restenosis of 50% or greater occurred in the 51 primarily closed CEAs.

CONCLUSION

Patch angioplasty reconstruction of CEAs with arteriotomies that extend distal to the carotid bulb gives excellent early and long-term outcomes. Saphenous vein-patched CEAs are superior to synthetic patched CEAs for stroke and restenosis prevention. Primary closure is safe and durable when complete end points and arteriotomies are within the carotid bulb.

Platelets and cytokines in concert with endothelial activation in patients with peripheral arterial occlusive disease

We tested the hypothesis whether circulating oncostatin-M (OSM), a cytokine that in vitro promotes fibrinogen biosynthesis and smooth muscle cell proliferation, or soluble CD40 ligand (CD40L; CD154), a leukocyte and platelet surface marker that stimulates endothelial cells, were associated: (a) with fibrinogen and other soluble cell adhesion molecules, such as P-selectin, vascular cell adhesion molecule-1 (VCAM-1), intercellular cell adhesion molecule-1 and platelet-endothelial cell adhesion molecule-1; or (b) with restenosis and platelet activation in 71 patients with peripheral arterial occlusive disease undergoing peripheral angioplasty (PTA). Platelet membrane activation markers (CD62P, CD63, activated GPIIb/IIIa) were immunologically measured at 0, 1, 24 and 48 h, and 3 and 6 months after PTA. Soluble cell adhesion molecules, endothelial markers and various hemostatic variables were measured before PTA. Of the patients, 42.3% developed restenosis within 6 months, defined as a >50% reduction of the lumen at the site of balloon dilatation. Soluble CD40L was not higher in the restenosis group. Interestingly, patients with high CD40L showed significantly higher soluble VCAM-1 (P < 0.01) and thrombomodulin (P < 0.01), as well as trends for higher soluble P- and E-selectin. Platelet activation was found uniformly increased mostly at 1 and 24 h, as well as at 3 and 6 months. OSM was measurable in 53.5% (6.9 +/- 9.4 pg/ml) of the patients and undetectable in the others. No differences in the rate of restenosis was found in these two groups, which did not differ with respect to fibrinogen (3.14 +/- 1.00 versus 3.21 +/- 0.70 g/l), or the other parameters. In conclusion, soluble CD40L is associated with higher endothelial biological markers that might implicate its involvement in endothelial activation. Platelet activation, probably intermittent, might play a significant role through the expression of CD40L as a source of activation signals to the endothelial cells. Free circulating OSM does not seem to correlate directly with fibrinogen or with other acute phase reaction proteins, the synthesis of which it could influence in vitro. This might well not mean, however, that OSM lacks this activity in vivo.

Early complications and endoleaks after endovascular abdominal aortic aneurysm repair: report of a multicenter study

OBJECTIVE

The aim of this study was the identification of risk factors for adverse events and the assessment of the early success rate in 1554 patients with abdominal aortic aneurysms (AAAs) who underwent treatment with endovascular technique between January 1994 and March 1999. For this purpose, the clinical and procedural data were correlated with observed complications and endoleaks.

METHODS

The data were collected from 56 European centers and submitted to a central registry. Patient characteristics, aortoiliac anatomic features, operative technical details, types of devices used, and experience of the teams of physicians were correlated with the occurrence of complications and endoleaks. The technical success rate was assessed according to the Society for Vascular Surgery/International Society for Cardiovascular Surgery, North American Chapter, guidelines. For the assessment of correlations between risk factors and adverse events, a multivariate logistic regression analysis was used.

RESULTS

The operative complications were grouped into three categories: failure to complete the procedure (39 patients, of which 27 underwent a conversion to an open AAA repair; 2.5%); device-related or procedure-related complications (149 patients; 10%); and arterial complications (51 patients; 3%). The most important risk factors for failure to complete the procedure included an aneurysm diameter of 60 mm or more and the need for adjuvant procedures. The factors that predicted device-related and arterial complications were the experience of the team with endovascular AAA treatment and the need for adjuvant procedures. Forty patients (2.6%) died within 30 days after operation. American Society of Anesthesiologists III and IV operative risk classification results predicted higher mortality rates than did American Society of Anesthesiologists operative risk classification I and II results. The patients who underwent operation in 1994, the first year documented in this registry, and those who required adjuvant procedures also had an increased risk of perioperative death. The incidence rate of systemic complications within the first 30 days (279 patients; 18%) was higher in patients aged 75 years or more, in patients with an impaired cardiac status, and in patients considered unfit for an open procedure. An endoleak was detected at the completion of the procedure in 16% of the cases and was still present after 1 month in 9%. The risk factors for primary endoleaks were female gender and age of 75 years and older. The observed technical success rate in this patient series was 72%.

CONCLUSION

The learning curve of the doctors and the need for adjuvant procedures were independent risk factors of operative device-related and arterial complications. The importance of proper instruction during an institution's initial phase with this treatment is emphasized by these observations. Although the endovascular management of AAAs is less stressful than open surgery, systemic complications were still the most common adverse events during the first postoperative month. These complications were associated with several patient-related factors, including advanced age, impaired cardiac status, and poor general medical condition. These observations may be a guide for improved patient selection for endovascular AAA repair.

Delayed onset of ascending paralysis after thoracic aortic stent graft deployment

Delayed spinal cord ischemia after thoracic aortic aneurysm repair is an infrequent but devastating complication. The use of stent grafts to exclude aortic aneurysms is thought to decrease the incidence of the neurologic deficit because there is no period of significant aortic occlusion. We report a case of paraplegia that progressed to quadriplegia occurring 48 hours after the apparently successful deployment of a thoracic aortic stent graft.

Endovascular aneurysm repair in high-risk patients

PURPOSE

The purpose of this study was to evaluate the role of endovascular aneurysm repair in high-risk patients.

METHODS

The elective endovascular repair of infrarenal aortic aneurysm was performed in 116 high-risk patients with either custom-made or commercial stent grafts. The routine follow-up examination included contrast-enhanced computed tomography (CT) before discharge, at 3, 6, and 12 months, and annually thereafter. Patients with endoleak on the initial CT underwent re-evaluation at 2 weeks. Those patients with positive CT results at 2 weeks underwent endovascular treatment.

RESULTS

Endovascular repair was considered feasible in 67% of the patients. The mean age was 75 years, and the mean aneurysm diameter was 6.3 cm. The American Society of Anesthesiologists grade was II in 3.4%, III in 65.5%, IV in 30.1%, and V in 0.9%. There were no conversions to open repair. Custom-made aortomonoiliac stent grafts were implanted in 77.6% of the cases, custom-made aortoaotic stent grafts in 11.2%, and commercial bifurcated stent grafts in 11.2%. The 30-day rates of mortality, major morbidity, and minor morbidity were 3.4%, 20.7%, and 12%, respectively, in the first 58 patients and 0%, 3.4%, and 3.4%, respectively, in the last 58. The late complications included five cases of stent graft kinking, two cases of femorofemoral graft occlusion, and three cases of proximal stent migration, one of which led to aneurysm rupture. At 2 weeks after repair, endoleak was present in 10.3% of the cases. All the type I (direct perigraft) endoleaks underwent successful endovascular treatment, whereas only one type II (collateral) endoleak responded to treatment. The technical success rate at 2 weeks was 86.2%, and the clinical success rate was 96.6%. The continuing success rate was 87.9%. Seventeen patients died late, unrelated deaths.

CONCLUSION

Endovascular aneurysm repair is safe and effective in patients at high risk, for whom it may be the preferred method of treatment.

Aortoduodenal fistula after endovascular stent-graft of an abdominal aortic aneurysm

Despite satisfying short- and middle-term effectiveness and feasibility, endovascular stent-grafting for abdominal aortic aneurysm is still under evaluation. We report a case of an aortoduodenal fistula after the use of this technique. Enlargement of the upper aneurysmal neck was followed by caudal migration of the major portion of the stent-graft, which resulted in kinking of the device in the aneurysmal sac. Ulcerations were found on adjacent portions of both the aneurysmal sac and the adjacent duodenum. Only the textile portion of the prosthetic contralateral limb separated the aortic lumen from the corresponding duodenal lumen. Early detection of complications after stent-grafting is essential to allow successful treatment, either surgical or endoluminal.

Endovascular repair of descending thoracic aortic aneurysms: an early experience with intermediate-term follow-up

PURPOSE

The purpose of this study was to report an initial experience with the endovascular repair of descending thoracic aortic aneurysm. Complications and intermediate-term morphologic changes were identified with the intent of altering patient selection and device design.

METHODS

Endografts were placed into 25 patients at high-risk for conventional surgical repair over a 3(1/2)-year period. Devices were customized on the basis of preoperative imaging information. Follow-up computed tomography scans were obtained at 1, 3, 6, and 12 months and yearly thereafter. Additional interventions occurred in the setting of endoleaks, migration, and aneurysm growth.

RESULTS

The overall 30-day mortality rate was 20% (12.5% for elective cases; 33% for emergent cases). There were 3 conversions to open repair. Neurologic deficits developed in 3 patients; 1 insult resulted in permanent paraplegia. Neurologic deficits were associated with longer endografts (P =.019). Three endoleaks required treatment, and 1 fatal rupture of the thoracic aneurysm treated occurred 6 months after the initial repair. Migrations were detected in 4 patients. The maximal aneurysm size decreased yearly by 9.15% (P =.01) or by 13.5% (P =.0005) if patients with endoleaks (n = 3 patients) were excluded. Both the proximal and distal neck dilated slightly over the course of follow-up (P =.019 and P =.001, respectively). The length of the proximal neck was a significant predictor of the risk for endoleakage (P =.02).

CONCLUSION

The treatment of descending thoracic aortic aneurysms with an endovascular approach is feasible and may, in some patients, offer the best means of therapy. Early complications were primarily related to device design and patient selection. All aneurysms without endoleaks decreased in size after treatment. Late complications were associated with changing aneurysm morphologic features and device migration. The morphologic changes remain somewhat unpredictable; however, alterations in device design may result in improved fixation and more durable aneurysm exclusion.

[Percutaneous treatment of superior vena cava obstruction]

Endovascular therapies represent the most efficient treatment of benign or malignant obstructions of the superior vena cava. The indication of stenting in case of malignant obstruction depends on the severity of the superior vena cava syndrome, the histological type of the tumor, and the response to radiotherapy and chemotherapy. Restoration of the superior vena cava patency is obtained in more than 90% of cases, with persistent good mid and long term results. Complications are rare, especially after early treatment. Stenting of benign obstructions, especially in patients who undergo hemodialysis, allows to restore venous accesses. However, indication of treatment may be discussed because the initial and late patencies are lower than in malignant obstructions.

Inhibition of platelet-neutrophil interactions by Fucoidan reduces adhesion and vasoconstriction after acute arterial injury by angioplasty in pigs

The selectin family of cell-adhesion molecules contributes to the interactions of leukocytes and platelets at the site of vascular injury. Such interactions enhance inflammatory reactions and thrombus formation during the arterial response to injury. In this study, we investigated the effects of a selectin inhibitor (Fucoidan) on platelet and neutrophil interactions after arterial injury produced by angioplasty in pigs. [51Cr]-platelet deposition and [111In]-neutrophil adhesion were quantified on intact, mildly, and deeply injured carotid arterial segments, produced by balloon dilation in control (saline, n = 7) and Fucoidan-treated (i.v.; 1 mg/kg, n = 6; 5 mg/kg, n = 5) pigs. In the control group, platelet deposition (x10(6)/cm2) was influenced by the severity of injury and increased significantly (p < 0.05) from 0.06+/-0.06 on intact endothelium to 3.8+/-0.6 and 33.6+/-4.9 on mildly and deeply injured segments, respectively. Fucoidan, 1 mg/kg, had no significant effect, although doses of 5 mg/kg reduced platelet deposition by 73% on deeply injured segments. The level of neutrophil adhesion (x10(3)/cm2) was also influenced by the severity of injury: it increased in the control group from 8.8+/-2.5 on intact endothelium to 226.6+/-45.5 and 397.4+/-61.3 on mildly and deeply injured arterial segments, respectively (p < 0.05). Again, 1 mg/kg Fucoidan had no effect, although doses of 5 mg/kg reduced neutrophil adhesion by 92% and by 84% on mildly and deeply injured segments, respectively. The effects of Fucoidan were associated with a 51% decrease in the vasoconstrictive response at the site of arterial injury. However, Fucoidan had no significant effect on either platelet aggregation or activated clotting time (ACT). In the in vitro perfusion experiments, Fucoidan inhibited both isolated platelet, and neutrophil, adhesion to damaged arterial surfaces. This inhibition was more pronounced in experiments using mixed cell preparations, indicating that Fucoidan interferes with platelet and neutrophil interactions. These results highlight the importance of selectins in the acute physiopathologic reactions related to platelet-neutrophil interactions after arterial injury.

[Comparative study of balloon dilatation and stent placement in primary angioplasty]

OBJECTIVE

To communicate our results with primary angioplasty (PA) and stenting de novo in acute myocardial infarction.

MATERIAL AND METHODS

163 patients (pts) had clinical diagnosis of MI with an average onset time of symptoms of 2.5 hours. They were divided in two groups: 100 pts with PA using only balloon (group I) and 63 pts with primary stenting (group II) (63 pts with 85 stents). A high pressure technique (14-16 atm) was used in group II and all pts were on salicylic acid and ticlopidine. Both groups were compared.

RESULTS

Clinical characteristics, infarct location and infarct related-artery were similar, being left anterior descending the more frequently vessel involved. Clinical success rate was higher in group II (97% vs 87%) and complication rate was threefold higher in group I (9% vs 3%). A mean follow up of 57 months in group I showed a 21% clinical and/or angiographic restenosis rate, while the 12 months follow up in group II failed to show any case of restenosis at all.

CONCLUSIONS

The use of stents in PA improves the results achieved with balloon procedures. There is a greater success rate, less complications and better survival patients who had the procedure while being in cardiogenic shock.

[Cytomegalovirus and arterial disease. Current aspects]

The cytomegalovirus (CMV) is the only microbial agent implicated in three particular types of arterial disease: coronary disease of the transplanted heart, post-angioplasty restenosis and atherosclerosis. The object of this article is to analyse the recent data on the role of CMV in these pathologies with an exhaustive review of the literature. The available data is mainly epidemiological but the interpretation is difficult because of the multiplicity and imperfections of the diagnostic techniques of the infection. However, the results are quite concordant in favour of a real association. Different physiopathological mechanisms are proposed. In coronary disease of the transplanted heart, the lesions could be initiated by an inflammatory process. In post-angioplasty restenosis, the virus seems able to trigger cellular proliferation by inhibiting the mechanisms of apoptosis. Finally, in atherosclerosis, CMV infection seems to promote atherothrombotic processes and accelerate the progression of atherosclerotic plaques by activating inflammatory cells. Direct methods of detection of viral DNA show the presence of the virus within these lesions. There is, therefore, epidemiological, anatomo-pathological and physiopathological evidence in favour of a relationship between CMV infection and these three forms of arterial disease.

[Cryopreserved arterial homografts. A treatment alternative for infected vascular reconstructions]

Deep wound infection or prosthetic vascular graft infection is one of the most challenging complications in vascular surgery with a substantial early and late morbidity and mortality. Surgical treatment usually consists of complete removal of infected vessels or prosthetic vascular grafts followed by extraanatomic bypass procedures. However, this method is associated with significant mortality and amputation rates. Herein, we report two patients with deep wound and prosthetic vascular graft infection who underwent successful in situ reconstruction with cryopreserved arterial homografts. Although the long-term results are missing, this approach may offer a possible treatment alternative for this potentially life-threatening complication.

Development of a coronary artery aneurysm three months after stent implantation: a case report

Coronary artery stents have been used widely to prevent acute closure as a bailout procedure, or to decrease restenosis after balloon angioplasty. Stent use has increased substantially in recent years due to the ease and simplicity with which stents provide a predictable angiographic result. However, few data exist on the long-term safety of stents. This case report describes a 63-year-old male patient who developed intimal dissection after balloon angioplasty and who underwent coronary stent placement of a sheathed stent (half Palmaz-Schatz stent, 3.5 mm in diameter and 7 mm in length) as a bailout procedure. Postdilatation with a 3.5-mm balloon was performed at the maximum pressure of 14 atmospheres with a satisfactory angiographic result. However, an aneurysmal dilatation at the stent site was noted three months later. High-pressure stent use without immediately visible vascular dissection by angiography may not be effective for prevention of coronary aneurysm development in a case such as this. Aneurysmal dilatation may be a late complication in cases of coronary artery stent placement.

Endothelial implants inhibit intimal hyperplasia after porcine angioplasty

The perivascular implantation of tissue-engineered endothelial cells around injured arteries offers an opportunity to study fundamental vascular physiology as well as restore and improve tissue function. Cell source is an important issue because the ability to implant either xenogeneic or allogeneic cells would greatly enhance the clinical applications of tissue-engineered grafts. We investigated the biological and immunological responses to endothelial cell xenografts and allografts in pigs 4 weeks after angioplasty of the carotid arteries. Porcine or bovine aortic endothelial cells were cultured within Gelfoam matrices and implanted in the perivascular space of 42 injured arteries. Both porcine and bovine endothelial cell grafts reduced the restenosis index compared with control by 54% and 46%, respectively. Perivascular heparin release devices, formulated to release heparin at twice the rate of release of heparan sulfate proteoglycan from endothelial cell implants, produced no significant reduction in the restenosis index. Endothelial cell implants also reduced occlusive thrombosis compared with control and heparin release devices. Host immune responses to endothelial implants were investigated by immunohistochemical examination of explanted devices and by immunocytochemistry of serum samples. The bovine cell grafts displayed infiltration of leukocytes, consisting primarily of lymphocytes, and caused an increase in antibodies detected in serum samples. Reduced cellular infiltration and no humoral response were detected in animals that received allografts. Despite the difference in immune response, the biological effects of xenografts or allografts did not differ significantly.

Selectin blockade reduces neutrophil interaction with platelets at the site of deep arterial injury by angioplasty in pigs

The adhesion of neutrophils to damaged arterial surfaces is increased in the presence of platelets by a mechanism implicating platelet P-selectin. Such interactions may enhance thrombus formation and the vascular response to injury. In this study, we investigated the effects of a selectin blocker (CY-1503), an analogue of sialyl Lewisx, on platelet and neutrophil interactions after arterial injury produced by angioplasty in pigs.51Cr-platelet deposition and 111In-neutrophil adhesion were quantified on intact, mildly and deeply injured carotid arterial segments, produced by balloon dilation, in control (saline, n=8) and treated (CY-1503, 15 mg/kg IV, n=7) pigs. The hematological parameters, the aggregation of whole blood in response to adenosine diphosphate, and the activating clotting time, as well as the heart rate and mean arterial blood pressure, were similar among groups and were not influenced significantly by CY-1503. The level of platelet and neutrophil adhesion increased significantly with the severity of arterial injury but was not influenced by CY-1503 on intact and mildly injured arterial segments. However, at the site of deep arterial injury, CY-1503 treatment was associated with a 58% reduction (P<0.01) in neutrophil adhesion, from 446.7+/-72.6x10(3) neutrophils/cm2 in the control group to 186.8+/-38.7x10(3) neutrophils/cm2 in the CY-1503-treated group, whereas platelet deposition remained unchanged (43.4+/-15.6x10(6) platelets/cm2 versus 50.1+/-12.2x10(6) platelets/cm2 in the control group). In in vitro adhesion experiments, using isolated platelet and neutrophil suspensions, we found that CY-1503 interfered with the adhesion of neutrophils to damaged arterial surfaces only in the presence of platelets. In contact with thrombogenic arterial surfaces, adherent and activated platelets supports neutrophil adhesion at the site of deep injury by an adhesive interaction involving neutrophil sialyl Lewisx. The inhibitory effect of CY-1503 on neutrophil interaction with adherent platelets may be clinically relevant in patients undergoing percutaneous transluminal coronary angioplasty where platelet and neutrophil interactions may enhance the acute and chronic arterial response to injury.

[Diagnostic value of endocoronary echography]

Intracoronary ultrasound allows in vivo examination of the various layers of the wall of arteries affected by atherosclerosis. Its use in the catheterisation laboratory has therefore allowed better understanding of the mechanism of the action of the various angioplasty procedures, allowing better guidance of the indications and better control of these techniques. It also helps to guide these procedures, thereby facilitating an optimal immediate result, which determines the long-term outcome. The characteristics of intracoronary ultrasound (high resolution, proximity of the arterial wall, echogenicity of constituents of the plaque) make it the instrument of choice to study the composition and structure of the plaque, which determine the clinical presentation and active potential, especially the risk of complications (rupture). The development of image and crude acoustic signal processing techniques have improved the performance of the analysis of these documents and raise hopes of one day being able to predict and anticipate plaque rupture.

Interleukin-10 inhibits postinjury tumor necrosis factor-mediated human vascular smooth muscle proliferation

BACKGROUND

Both ischemic and direct vascular injury (angioplasty) result in the elaboration of proinflammatory substances, including tumor necrosis factor alpha (TNF), which may regulate vascular smooth muscle cell (VSMC) proliferation and promote vessel stenosis. Interleukin-10 (IL-10) is a pleiotropic cytokine with potent antiinflammatory effects in many cells lines. We hypothesized that IL-10 could be used therapeutically to influence vascular remodeling by inhibiting TNF-induced VSMC proliferation. The purposes of this study were (1) to determine whether human myocardium produces endogenous TNF in response to ischemia-reperfusion, (2) to examine the effect of TNF on human arterial smooth muscle proliferation, and (3) to explore the potential therapeutic effect of IL-10 on unstimulated and TNF-stimulated VSMC proliferation.

MATERIALS AND METHODS

Right atrial muscle was obtained from patients undergoing elective cardiac surgery. Atrial muscle was subjected to simulated ischemia and reperfusion in vitro and TNF was measured by immunoassay. Human aortic VSMCs were isolated and cultured. Proliferation assays were performed to determine the effect of TNF and IL-10 on VSMC growth.

RESULTS

Ischemia-reperfusion resulted in an increase in atrial myocellular TNF (94.5 +/- 15.8 pg/g wet tissue versus control 12.9 +/- 4.4 pg/g wet tissue, P < 0.002). Compared with control, TNF stimulated concentration-dependent VSMC proliferation (P < 0.005). IL-10 alone did not influence VSMC growth. However, following TNF stimulation, IL-10 inhibited VSMC growth at a dose as low as 0.1 pg/ml (P < 0.005).

CONCLUSIONS

Ischemia-reperfusion insult results in increased endogenous myocardial TNF accumulation. TNF stimulates VSMC growth which is abrogated by physiologically relevant levels of IL-10. This antiinflammatory cytokine may prove to be an effective therapeutic agent in regulating vessel wall remodeling following both ischemic and direct cardiovascular injury.