Coronary artery stenting.
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Angioplasty, Balloon, Coronary↗
Biomedical subjects
Martin B Leon
Publications and source records attributed to Martin B Leon.
Results of the Jostent coronary stent graft implantation in various clinical settings: procedural and follow-up results.
The Jostent coronary stent graft (CSG) is composed of a PTFE layer sandwiched between two stainless steel stents, initially introduced for the treatment of coronary perforations and aneurysms with excellent results. By providing a mechanical barrier, this stent design also may be beneficial in the treatment of complex ulcerated lesions and in-stent restenosis by preventing debris protrusion and neointimal proliferation through the stent struts. To evaluate the safety and efficacy of this stent graft, we implanted 78 CSGs in 70 patients for a broad range of indications, including coronary perforations, aneurysms, degenerated saphenous vein grafts, complex lesions, and in-stent restenosis. The primary angiographic success rate (95.9%) was high, and using intravascular ultrasound (IVUS) guidance during stent implantation and high inflation pressures (19.3 +/- 3.2 atm), stent expansion with optimal symmetry was achieved in 94.7%. One limitation of the Jostent CSG was the side-branch occlusion rate (18.6%) and the resulting non-Q-wave infarction rate in seven cases (mean CK elevation, 238 U/l), acute Q-wave MI in two cases, and transient ventricular fibrillation in one patient after occlusion of the proximal RCA side branch without further complications. Subacute stent thrombosis occurred in four cases (5.7%) 7 to 70 days after stent implantation, despite using combined antiplatelet therapy with aspirin (ASA), ticlopidine, and/or clopidogrel for 30 days. Angiographic follow-up was available in 56 patients (80.0%) after a mean of 159 +/- 49 days, and follow-up IVUS was available in 38 cases. The overall restenosis rate (> 50% diameter stenosis) was 31.6% manifest primarily as edge restenosis (29.8% stent edge vs. 8.8% stent center; P < 0.001). IVUS examinations showed a minimal late lumen loss of 0.4 +/- 2.2 mm(2) within the center of the stent graft vs. 3.2 +/- 2.3 mm(2) at the stent edges (P < 0.001). The restenosis rate in the prespecified subgroups was 33.3% for saphenous vein grafts (2/6 lesions), 30.0% in complex lesions (6/20 lesions), and 38.5% (10/26 lesions) for the treatment of in-stent restenosis. Implantation of the Jostent CSG is feasible and safe, even in complex lesion subsets, and is associated with high primary success rates provided major side branches are avoided. The use of this stent may require an extended time course of antiplatelet therapy. Frequent focal stent edge renarrowing influences the overall restenosis rate. However, in treatment of complex in-stent restenosis and vein graft lesions, stent grafts may offer benefit over conventional therapies. Covered stents such as the JoMed coronary stent graft may become essential for bailout treatment of coronary perforations.
Adult↗
Estrogen-eluting, phosphorylcholine-coated stent implantation is associated with reduced neointimal formation but no delay in vascular repair in a porcine coronary model.
Estrogen can inhibit intimal proliferation and accelerate endothelial regeneration after angioplasty. This suggests that estrogen may prevent in-stent restenosis. Unlike other therapies to prevent restenosis, estrogen may also not delay endothelial regrowth, thereby avoiding the risk of late stent thrombosis. The purpose of this work was to determine the effect of a 17beta-estradiol-eluting stent on neointimal formation in a porcine model. Each artery of six pigs was randomized to either a control, low-dose, or high-dose 17beta-estradiol-eluting stent. All animals were sacrificed at 30 days for histopathological analysis. There was a 40% reduction in intimal area in the high-dose stents compared with control stents (2.54 +/- 1.0 vs. 4.13 +/- 1.1 mm(2), for high dose vs. control, respectively; P < 0.05). There was complete endothelial regeneration at 30 days and similar inflammatory response to stenting on histopathology in all the stent groups. This is the first study to show that 17beta-estradiol-eluting stents are associated with reduced neointimal formation without affecting endothelial regeneration in the pig model of in-stent restenosis. Estrogen-coated stents may have a potential benefit in the prevention and treatment of in-stent restenosis.
Animals↗
Coronary intervention in the diabetic patient: improved outcome following stent implantation compared with balloon angioplasty.
BACKGROUND: Diabetic patients undergoing coronary interventional procedures are at increased risk of restenosis and adverse clinical events. The relative impact of stents compared with balloon angioplasty on the outcome of percutaneous intervention in diabetics remains controversial. HYPOTHESIS: The goal of this study was to determine whether stent placement was superior to balloon angioplasty in reducing restenosis of diabetic patients undergoing coronary intervention. METHODS: The STRESS Trial was a prospective randomized comparison of stent placement and balloon angioplasty in the treatment of new native coronary lesions. Of 594 randomized patients. 92 (16%) were diabetic. In this substudy analysis of the STRESS Trial, the outcomes after stenting and balloon angioplasty in diabetic patients were compared. The primary endpoint was restenosis as determined by angiography at 6 months. Clinical outcomes at 1 year were assessed. RESULTS: Procedural success was achieved in 82% of diabetic patients assigned to angioplasty and in 100% assigned to stenting (p < 0.01). Compared with angioplasty, stenting resulted in a larger postprocedural lumen diameter (2.34 +/- 0.44 vs. 1.87 +/- 0.52 mm, p < 0.001) and greater acute luminal gain (1.61 +/- 0.47 vs. 1.06 +/- 0.46 mm, p < 0.001). At 6 months, stenting conferred a larger lumen (1.69 +/- 0.57 vs. 1.38 +/- 0.60 mm, p = 0.03) and greater net luminal gain (0.97 +/- 0.55 vs. 0.52 +/- 0.52 mm, p < 0.001). Restenosis occurred in 60% of the angioplasty group and in 24% of the stent group (p < 0.01). This was accompanied by a lower need for repeat target vessel revascularization after stenting (31 vs. 13%, p < 0.03). CONCLUSIONS: Compared with balloon angioplasty, stent placement in diabetic patients with focal de novo lesions resulted in superior procedural results, reduced restenosis, and improved clinical outcome with fewer repeat revascularization procedures.
Angioplasty, Balloon↗
New-device angioplasty in women: clinical outcome and predictors in a 7,372-patient registry.
BACKGROUND: Female gender has been identified as an independent predictor of early complications and mortality after conventional balloon angioplasty. To gain insight into the outcome of women after new-device angioplasty, we reviewed the early and late clinical outcome of 7,372 patients undergoing new-device angioplasty between 1991 and 1996 at the Washington Hospital Center. METHODS: Patients (2,077 women and 5,295 men) with native coronary artery (82.5%) or saphenous vein graft lesions undergoing new-device angioplasty were included in the study. In-hospital and 1-year major adverse cardiac events (MACE), including death, myocardial infarction, and target lesion revascularization (TLR), were recorded and compared on the basis of gender. Multivariable logistic regression analysis was performed to identify predictors of in-hospital and late mortality, follow-up MACE, and TLR. RESULTS: Women had more baseline comorbid risk factors and smaller reference vessel size compared with men. Women had a higher in-hospital cardiac mortality (1.39% vs 0.66%, P = 0.002), TLR (2.78% vs 1.81%, P = 0.008), and congestive heart failure (4.18% vs 2.29%, P < 0.001) compared with men. Overall in-hospital MACE tended to be higher among women (4.2% vs 3.3%, P = 0.074). Women had a higher 1-year mortality rate (4.39% vs 3.26%, P = 0.018), but a lower follow-up TLR (15.0% vs 18.1%, P = 0.001) and a lower overall MACE rate (29.2% vs 32.7%, P = 0.007) compared with men. Female gender was an independent predictor of in-hospital mortality (odds ratio 2.28, P = 0.02), but not late mortality. CONCLUSIONS: Although female gender appears to carry an inherent risk of in-hospital mortality after new-device angioplasty, the procedural success and mortality rates are favorable compared with those associated with balloon angioplasty series. The long-term clinical outcome of women after new-device angioplasty is excellent. The use of new devices is a safe and effective alternative strategy for the treatment of women with ischemic coronary artery disease. Device-specific outcomes, including stents, will require further evaluation.
Angioplasty↗
Predictors of clinical outcome following NIR stent implantation for coronary artery disease: analysis of the results of the First International New Intravascular Rigid-Flex Endovascular Stent Study (FINESS trial).
BACKGROUND: Patient and procedural characteristics associated with major adverse cardiac events following balloon angioplasty have been identified. Factors predictive of angiographic restenosis following coronary stent implantation have been reported, although patient variables associated with adverse clinical outcome are not well defined. HYPOTHESIS AND METHODS: To identify predictors of adverse clinical outcome following NIR stent implantation, clinical and angiographic characteristics of patients enrolled in the FINESS Trial were subjected to stepwise logistic regression analysis. From December 1995 through March 1996, NIR stent implantation was attempted in 255 patients (341 lesions) enrolled prospectively in a multicenter registry with broad entry criteria. RESULTS: On stepwise logistic regression analysis, the presence of multivessel disease, diabetes, and the total length of the stented segment were predictive of major adverse cardiac events during 6-month follow-up. For every 1 mm increase in stent length, the risk for the combined end point of death or myocardial infarction increased by 3%. Lesion length was not predictive of clinical events on multivariate analysis. CONCLUSIONS: Our data raise the possibility that an attempt to use shorter stents to cover significant stenoses, but not adjacent areas of visible narrowing, may improve outcome.
Coronary Artery Disease↗
Perspectives of drug-eluting stents: the next revolution.
Coronary stent implantation has become a well established therapy in the management of coronary artery disease (CAD). Although the Stent Restenosis Study (STRESS) and Belgium-Netherlands Stent (BENESTENT) trials demonstrated convincingly that stenting is superior to percutaneous transluminal coronary angioplasty with respect to restenosis in de novo lesions, there is, however, still a high incidence (10 to 50%) of restenosis following stent implantation. Improvements in stent design and implantation techniques resulted in an increase in the use of coronary stents and today, in most centers in the US and Europe, stenting has become the predominant form of nonsurgical revascularization accounting for about 80% of all percutaneous coronary intervention procedures. Coronary stents provide luminal scaffolding that virtually eliminates elastic recoil and remodelling. Stents, however, do not decrease neointimal hyperplasia and in fact lead to an increase in the proliferative comportment of restenosis. Agents that inhibit cell-cycle progression indirectly have also been tested as inhibitors of vascular proliferation. When coated onto stents, sirolimus, a macrolide antibiotic with immunosuppressive properties, and paclitaxel and dactinomycin, both chemotherapeutic agents, induced cell-cycle arrest in smooth muscle cells (SMC) and inhibited neointimal formation in animal models. Preliminary clinical studies with drug-eluting stents produced dramatic results eliminating restenosis in large and mid-size arteries. Quantitative coronary angiography and intravascular ultrasound demonstrated virtually complete inhibition of tissue growth at 6 and 12 months after sirolimus-eluting stent implantation. Results are also very encouraging with paclitaxel-coated stents. However, it needs to be proven that current drug-eluting stents will produce similar results in 'real life' interventional practice (long lesions, lesions in small vessels, in vein grafts, chronic total occlusions, and bifurcated and ostial lesions). The ongoing randomized, double-blind sirolimus-coated Bx Velocity trade mark balloon expandable stent in the treatment of patients with de novo coronary artery lesions (SIRIUS) trial may answer some of these concerns. With further improvements, including the expansion of drug-loading capacity, double coatings and coatings with programmable pharmacokinetic capacity using advances in nanotechnology (which may allow for more precise and controlled release of less toxic and improved molecules), we think that in the next few years the practice of interventional cardiology may undergo major changes. A new era of dramatic improvements in the treatment of CAD may have dawned. The prospect of approval of this technology should herald a host of clinical trials to revisit basic assumptions about the place of coronary stenting in the contemporary care of obstructive (and nonobstructive) CAD.
Angioplasty, Balloon, Coronary↗
Acute angiographic and clinical results of the NIR w/SOX stent.
Acute angiographic and clinical results of the NIR w/SOX stent (Boston Scientific/Scimed, Inc., Maple Grove, Minnesota) were evaluated. Between March 2000 and May 2000, a total of 102 lesions in 88 patients underwent stenting with the NIR w/SOX stent. The reference vessel diameter and lesion length were 2.97 +/- 0.50 mm and 16.2 +/- 6.5 mm, respectively. The minimal lumen diameter increased from 0.68 +/- 0.45 to 3.07 +/- 0.50 mm. Stent delivery failure was observed in 4 lesions (3.9%). On the other hand, the NIR w/SOX stent was successfully delivered in 7 of 9 lesions that had unsuccessful delivery of other kinds of stents. Angiographic success was observed in all except 1 lesion where the NIR w/SOX stents could not be delivered. There were no procedural myocardial infarctions or deaths. In one case, procedural coronary bypass surgery was performed. There was no acute closure or subacute stent thrombosis. Despite unfavorable lesion characteristics, the NIR w/SOX stent achieves high procedural success and acceptable stent delivery. Furthermore, it may have a high probability to be delivered in lesions where other kinds of stent result in unsuccessful delivery.
Aged↗
Anti-angiogenesis: A new potential strategy to inhibit restenosis.
Microvessels are an integral component of the neointima developing in response to the acute vascular injury resulting from angioplasty. These vessels originate from the vasa vasorum of the adventitia, and as such appear similar to the microvessels present in atherosclerotic plaques. Several angiogenic factors have been found in atherosclerotic plaques and have been associated with increased microvascularity. In addition, most of these agents - either directly or indirectly - also induce smooth muscle cell (SMC) proliferation, an essential component of the developing neointima. We therefore propose: (1) these newly formed blood vessels are necessary for the development, maintenance, and expansion of the neointimal lesions present in restenosis; (2) the initiation, regulation and maintenance of these vessels is, at least in part, due to the coordinate sequential expression of hypoxia-inducible factor 1 (HIF-1), vascular endothelial growth factor (VEGF), angiopoietin-1 (Ang-1), and/or other angiogenic factors such as the fibroblast growth factor (FGF) family of proteins; (3) targeted disruption of the signal transduction pathways modulated by these molecules may reduce vasa vasorum expansion and SMC proliferation. These effects, in turn, may inhibit neointimal expansion and thus the development of restenosis, especially following stenting.
Journal Article↗
Intravascular-ultrasound-guided percutaneous transluminal coronary angioplasty/provisional stent implantation strategy: impact on long-term clinical follow-up.
Two hundred and eighty-four consecutive patients with 438 native coronary artery stenoses were enrolled prospectively in a study of intravascular ultrasound (IVUS)-guided percutaneous transluminal coronary angioplasty (PTCA) with provisional stenting: (1) aggressive lesion-site media-to-media balloon-sizing; (2) IVUS-assessment of residual lumen dimensions to identify optimal PTCA results (minimum lumen area = 65% of the average of the proximal and distal reference lumen areas or = 6.0 mm(2) and no major dissection); and (3) liberal stent crossover. Overall, 206 stenoses in 134 patients (47%) were treated with PTCA alone. Reasons for crossover were flow-limiting or lumen-compromising dissections in 28% of patients and suboptimal IVUS minimum lumen area in 72% of patients. At one year, 8% of stenoses in the PTCA group and 16% in the stent crossover group required revascularization. In approximately half of the patients treated using an IVUS-guided aggressive PTCA strategy, stent implantation could be avoided without sacrificing an increase in acute complications or worse clinical outcome.
Journal Article↗
Intravascular ultrasound observations of atherosclerotic lesion formation and restenosis in patients with diabetes mellitus.
Coronary artery disease is more aggressive in diabetic patients than in nondiabetics; they have more diffuse disease, higher mortality rates and worse clinical outcomes after coronary interventions. Intravascular ultrasound (IVUS) produces transmural tomographic images of the coronary arteries in vivo. Recent IVUS studies have provided new insights into the mechanisms of stenosis formation and restenosis in both nondiabetic and diabetic patients. Arterial remodeling is defined as a change in arterial area. During atherogenesis, an increase in arterial area usually accompanies plaque accumulation to delay lumen compromise. Stenosis formation is related to: (a) the rate of plaque accumulation versus the rate of positive remodeling; and (b) the limits and ultimate failure of positive remodeling. However, there is a marked variability in remodeling. IVUS studies have suggested that remodeling may be impaired in some diabetic patients during atherogenesis. Following non-stent catheter-based interventions, serial (post-intervention and follow-up) IVUS studies have shown that the change in lumen area correlates better with the change in arterial area (remodeling) than with the change in plaque area (neointimal hyperplasia). In some patients, a positive remodeling response mitigates against the increase in plaque area to limit late lumen loss and restenosis. Neointimal hyperplasia is exaggerated in diabetic patients. Despite this, there is a reduced frequency of positive remodeling, potentially similar to the impaired positive remodeling in some diabetic patients during atherogenesis. Failed or inadequate arterial remodeling may contribute to the pathogenesis and natural history of atherosclerotic coronary artery disease in diabetic patients.
Journal Article↗