High-pressure Stent Deployment Research Articles

Intraprocedural endothelial cell seeding of arterial stents via biotin/avidin targeting mitigates in-stent restenosis

Impaired endothelialization of endovascular stents has been established as a major cause of in-stent restenosis and late stent thrombosis. Attempts to enhance endothelialization of inner stent surfaces by pre-seeding the stents with endothelial cells in vitro prior to implantation are compromised by cell destruction during high-pressure stent deployment. Herein, we report on the novel stent endothelialization strategy of post-deployment seeding of biotin-modified endothelial cells to avidin-functionalized stents. Acquisition of an avidin monolayer on the stent surface was achieved by consecutive treatments of bare metal stents (BMS) with polyallylamine bisphosphonate, an amine-reactive biotinylation reagent and avidin. Biotin-modified endothelial cells retain growth characteristics of normal endothelium and can express reporter transgenes. Under physiological shear conditions, a 50-fold higher number of recirculating biotinylated cells attached to the avidin-modified metal surfaces compared to bare metal counterparts. Delivery of biotinylated endothelial cells to the carotid arterial segment containing the implanted avidin-modified stent in rats results in immediate cell binding to the stent struts and is associated with a 30% reduction of in-stent restenosis in comparison with BMS.

Impact of very high pressure stent deployment on angiographic and long-term clinical outcomes in true coronary bifurcation lesions treated by the mini-crush stent technique: A single center experience

BackgroundPercutaneous coronary intervention (PCI) for bifurcation lesions (BL) using 2 stents technique is known to be associated with high rates of procedural failure especially on the side branch (SB) mainly due to stent incomplete apposition. Stent deployment at very high pressure (SDHP) may lead to better stent expansion and apposition. However, SDHP may also be at the origin of deeper wall injury resulting into major cardiac adverse events. No data are available on evaluation of SDHP in BL treated by a mini-crush stent technique. MethodsOne hundred and thirteen consecutive patients underwent PCI for BL (Medina 1, 1, 1) using a mini-crush stent technique with SDHP defined as ≥20atm. An angiographic follow-up was performed at 6 month and clinical follow-up was obtained at a median of 3 years. ResultsStent deployment mean pressures were 20±1.4atm (range 20–25) in the main vessel (MV) and 20±1.5atm (range 20–25) in SB. Simultaneous final kissing balloon was used in 92% of cases. PCI was successful in 100%. Angiographic follow-up was obtained in 83% of patients. Restenosis rate was 13% (12% restenosis in the SB) with only one case (0.8%) of SB probable thrombosis. Another case of late stent thrombosis occurred at a 3 years clinical follow-up. ConclusionCompared with previously published studies in which stents were deployed at lower pressure, SDHP does not increase the restenosis rate in BL using mini-crush stent technique but seems to reduce the rate of stent thrombosis.

Combined drug-eluting stent and supplementary paclitaxel-eluting balloon application at side branch ostium for in-stent restenotic true bifurcation lesion

In-stent restenotic bifurcation lesion (ISRB) is defined as an in-stent restenosis (ISR) with a sizeable side branch (SB) arises from within the disease segment (Fig. 1). Owing to a large volume of proliferating neointimal tissue and extracellularmatrix deposition [1,2], any intervention would readily predispose to SB occlusion, particularly if the SB ostium is diseased (true bifurcation lesions), which is very difficult to manage as the SB ostium is already covered with a layer of stent strut. Drugeluting stent (DES) implantation over the old stent (stent sandwich) is among one of the definitive treatments for ISR [3]. In this special lesion subgroup, however, stent implantation would bring more troubles by causingmore plaque extrusion in both radial and longitudinal direction after high-pressure stent deployment, and covering the SB ostiumwith 1more layer of stent strut. On the other hand, paclitaxel-eluting balloon (PEB) offers another platform of drug delivery without adding a new metal layer; its role has also been proven in ISR [4,5]. The advent of PEB, together with the current DES, provides many other alternatives to the treatment of this special bifurcation subgroup. A 67-year-oldmanwho got smoking, diabetesmellitus and hypertension as cardiovascular risk factors had known coronary artery disease with percutaneous coronary intervention to left anterior descending artery (LAD) bifurcation about 9 years ago. At that time, a sirolimuseluting stent (Cypher 2.5 × 18 mm) was deployed in mid LAD with kissing balloon inflation to LAD/diagonal bifurcation using 2.0 mm and

EFFICACY OF A STANDARDIZED PROLONGED HIGH–PRESSURE STENT DEPLOYMENT PROTOCOL COMPARED WITH A HIGH–PRESSURE RAPID INFLATION/DEFLATION SEQUENCE AS EVALUATED BY OPTICAL COHERENCE TOMOGRAPHY

Previous studies have demonstrated that high–pressure stent deployment reduces the incidence of stent thrombosis (ST) and probably decreases in–stent restenosis. However, there is no consensus as to the protocol for high–pressure inflation. In patients undergoing routine PCI and in an attempt

"Real World" Adhoc Percutaneous Coronary Interventions With Use of Sirolimus Eluting Stents: A Single Operator Experience and Long-term Follow-up

BACKGROUND: Drug eluting stents (DES) have ushered in a new era in percutaneous coronary intervention (PCI), curtailing significantly the restenosis rates compared with bare metal stents (BMS). However, their use has been plagued with the late stent thrombosis phenomenon. OBJECTIVE : During a 5-year period, sirolimus-eluting stents (SES) were employed in 260 patients among 675 consecutive patients submitted to PCI by a single-operator with a uniform technique. The objective of this study was to assess the clinical and angiographic results and to report the incidence of stent thrombosis and the long-term outcome in these patients. METHODS & PATIENTS : A consistent single-operator approach with 0.5 mm stent oversizing and high pressure ( > 12-18 bar) stent deployment was adopted, routinely combined with long-term dual antiplatelet therapy for at least a two-year period post-implantation. The study included 213 men and 47 women, aged 64 + 12 years, who presented with stable angina and/or positive exercise test (n=54), unstable coronary syndrome (n=125), or acute myocardial infarction (MI) (n=81). The dilated vessel was the left main stem (n=4), left anterior descending and/or its diagonal branch (n=178), the right coronary (n=103), the circumflex and/or its obtuse marginal branch (n=89), the ramus branch (n=10), a saphenous vein (n=11) or arterial (n=2) graft. Three groups were compared: 104 (40%) patients receiving SES alone (Group A), 122 patients receiving SES plus other DES (Group B), and 34 patients receiving SES plus BMS (Group C). RESULTS : The majority (93.8%) of PCI procedures were performed adhoc during the same session of coronary angiography. All 3 groups had similar demographics, mean age (62-66 years), initial stenosis (88-89%) and mean ejection fraction (45-55%). Procedural success (99-100%) and residual stenosis ( 24 months. Over 16.3 + 14.7 months of follow-up, survival free of events (death, MI, stroke, repeat revascularization and restenosis) was excellent at 98%, 96%, and 97% at 12 months and 95%, 90% and 97% at 24 months for groups A, B and C respectively; long-rank (Mantel-Cox) test p value= 0.27. Clinical restenosis rates were low in all 3 groups (0% vs 1.6% vs 5.9%) (p=NS). Possible very late stent thrombosis could be suspected in 1 patient (group B) who had sudden cardiac death at 32 months after the procedure. CONCLUSION: In a consecutive series of 260 patients receiving SES and/or other stents, a uniform single-operator approach with 0.5 mm stent oversizing and high-pressure ( > 12-18 bar) deployment routinely combined with long-term dual antiplatelet therapy resulted in high procedural success ( > 99%), very low rate of subacute (0.4%) and late stent thrombosis (0.4%), very low clinical restenosis rates (0-5.9%) and overall excellent survival free of cardiovascular events at 1 and 2 years.

AS-96: Feasibility of High-Pressure Stent Deployment in ST-Segment Elevation Acute Myocardial Infarction

In the acute myocardial infarction (AMI), aggressive high-pressure stent deployment (HPSD) may dislodge more atherosclerotic plaque and thrombus distally but possibly reduce the risk of stent underexpansion and in-stent restenosis (ISR). We retrospectively analyzed the feasibility of HPSD in the AMI population.

Simultaneous multivessel acute drug-eluting stent thrombosis

Stent thrombosis (ST) in the era of bare metal stents (BMS) using high-pressure stent deployment and combined anti-platelet therapy is an uncommon but feared complication. There is concern for an elevated risk of stent thrombosis (ST) with drug-eluting stents (DES). We describe a case of simultaneous multivessel drug-eluting stent thrombosis 8 h after deployment of paclitaxel-eluting stents in the right coronary (RCA) and left anterior descending (LAD) arteries.

Nonocclusive subacute stent thrombosis as a source of distal macroembolism

With high pressure stent deployment and combined of the long subtotal occlusion, a 3.0/12 mm S670x (Medantiplatelet therapy the incidence of subacute stent thrombosis is currently 1–2%. Increased risk for stent thrombosis includes lower stent diameter, longer or more implanted stents and acute conditions with intracoronary thrombus formation. Failure of adequate stent expansion to the vessel wall also inclines to thrombus formation in the treated coronary segment [1,2]. The importance of the potential of distal embolisation during intervention on a coronary lesion is increasingly recognised as an advent result for the distal coronary perfusion. This risk is the most prominent during recanalisation of a totally and acutely occluded artery in the case of acute myocardial infarction, but other scenarios (chronically occluded artery, unstable coronary plaque with thrombus apposition or degenerated venous grafts) are also prone to distal embolisation [3,4]. After the coronary intervention, the possibility of distal embolisation in the case of a newly generated thrombus is clear, but according to our knowledge spontaneous distal macroembolisation had not been reported after coronary stent implantation. We report a patient with inferior acute myocardial infarction treated by rescue percutaneous coronary intervention with stent implantation whose symptoms recurred on the third day caused by the occlusion of a distal branch that had been intact before. Angiographic signs revealed thrombus formation inside the stent as the source of distal macroembolisation. Recanalisation of the distal occlusion with balloon dilatation and redilatation of the stent was performed successfully and the further course of the patient was uneventful. A 68-year-old male patient in acute inferior myocardial infarction treated by streptokinase was transferred for rescue PCI because of ongoing ischaemic signs. After predilatation

Reduced incidence of clinical restenosis with newer generation stents, stent oversizing, and high-pressure deployment: single-operator experience.

Over the last 4 years, several newer generation stents have become available, promising to change the scenery of coronary angioplasty (PTCA) with its attendant restenosis rate. The aim of this study was to review prospectively the results of a single operator adopting a uniform approach with approximately 0.5 mm stent oversizing and high-pressure (> or = 12-16 bar) deployment and compare them with conventional PTCA in a series of 244 consecutive patients. The study included 203 men and 41 women, aged 59 +/- 11 years, who presented with stable angina and/or positive exercise testing (n = 75), unstable angina (n = 161), or acute myocardial infarction (n = 8). Dilated vessels included the left anterior descending artery (n = 139), the right coronary artery (n = 86), the left circumflex artery (n = 47), the ramus branch (n = 4), or venous grafts (n = 2). Stents were implanted for dissection, suboptimal PTCA result, and electively. Two groups were compared: 83 patients who underwent balloon PTCA alone and 161 patients who also received stent(s). The two groups had similar demographics, age (58 +/- 10 vs. 59 +/- 11 years), initial vessel stenosis (92 +/- 7 vs. 93 +/- 6%), and left ventricular ejection fraction (51 +/- 9 vs. 51 +/- 8%). Procedural success was also similar (97.6 vs. 99.4%), but as expected the residual stenosis was much lower in the stent group (< or = 0 vs. 17%). The following stents were employed: J & J (n = 1), NIR (n = 117), ACS (n = 59), AVE (n = 9), Inflow GoldFlex (n = 9), Crossflex (n = 5), Wictor (n = 1), Jostent (n = 16), R stent (n = 9), Seaquence (n = 2) and Wallstent (n = 1). Single stents were used in 118 patients, two stents in 31 patients, three in 6 patients, and four in 6 patients. There was one in-hospital death at 3 days unrelated to the procedure. There were no events of subacute stent thrombosis; all patients in the stent group received combined therapy with aspirin and ticlopidine, the latter for 1 month. During 18 +/- 14 months, the clinical restenosis rate was significantly lower in the stent group (6.9%) than in the PTCA group (28.4%) (p = 0.001). In a series of 244 consecutive patients, newer generation stents and a consistent approach of stent oversizing and high-pressure stent deployment by a single operator resulted in high procedural success (99%), lack of stent thrombosis (0%), and a very low clinical restenosis rate (7%).

Intravascular ultrasonography in the evaluation of results of coronary angioplasty and stenting

The main advantage of intravascular ultrasonography (IVUS) over angiography in assessing the effect of coronary interventions is the ability of IVUS to directly visualize the vessel wall. IVUS often reveals a high residual plaque burden after angiographically successful angioplasty, and this can motivate the operator to use additional, more aggressive measures in an attempt to increase lumen dimensions. Studies using IVUS imaging before and after balloon angioplasty have shown that luminal gain after percutaneous transluminal coronary angioplasty (PTCA) results from a combination of plaque reduction and vessel wall stretch. Minimal luminal area and residual area stenosis after PTCA and stent deployment, as measured by IVUS, have been shown to be predictors of restenosis. IVUS studies have pointed to vessel shrinkage, not intimal hyperplasia, as the main mechanism of restenosis after PTCA. IVUS guidance of stent deployment has often revealed inadequate stent expansion despite optimal results on angiography, leading to high-pressure stent deployment with significant additional luminal gain. Restenosis rates may be lower with IVUS-guided stent deployment.

In vivo tomographic assessment of the heart and blood vessels with intravascular ultrasound

Intravascular ultrasound (IVUS) has emerged from being a research tool to becoming an intrinsic part of modern invasive cardiology mainly due to imaging micro anatomy in vivo. For the first time, it is possible to base therapeutic decisions not only on lumenograms but also on vessel wall assessment. IVUS has both diagnostic and intervention associated potential. The diagnostic strength of IVUS is its ability to describe compensatory coronary artery enlargement as a response to arteriosclerosis, to assess intermediate lesions, and to reveal occult left main stem disease and angiographically "silent" arteriosclerosis. The intervention associated potential of IVUS is the optimal device selection, i.e., rotablators in calcified lesions or atherectomy devices in large plaque burden. The effects of PTCA on vessel wall morphology can be studied in great detail and the effect on luminal gain can be assessed. Several groups have shown that the residual plaque area ("plaque burden") even after angiographically successful PTCA still lies in the range of 60%. A significant reduction in this number may influence long-term outcome after PTCA. Minimal luminal area and residual plaque area after PTCA seem to be indicators of restenosis, while the presence or absence of dissections seems to be less predictive. The main mechanism of restenosis after PTCA is vessel shrinkage, not intimal hyperplasia. Intravascular monitoring of stent expansion led to high-pressure stent deployment with a significant increase in post-procedural luminal diameters and the ability to withhold anticoagulation in patients with optimal stent deployment. In pulmonary and aortic diseases, IVUS contributed significantly to the understanding of aortic dissection and pulmonary hypertension. Additionally, with intracardiac ultrasound left and right ventricular function can be assessed. Intracardiac ultrasound has gained clinical usefulness for guiding transcatheter ablation in patients with conduction system abnormalities. In the future, integrated devices, such as balloons on IVUS catheters, steerable catheters, integrated flow and pressure transducers, tissue characterization, and 0.018" IVUS guide wire will further enhance the usefulness of IVUS.

Intravascular ultrasound--the new gold standard?

Intravascular ultrasound (IVUS) has evolved to a research tool to an intrinsic part of modern invasive cardiology. The main reason is the capability to obtain "in-vivo" micro anatomy by means of miniaturized echo-transducers with an outer diameter of 2.9-3.5 French. For the first time it is possible to base decisions not only on lumenograms but also on vessel wall assessment. The capabilities of IVUS can be divided in its diagnostic and intervention associated potentials. The diagnostic strength of IVUS is the ability to monitor compensatory coronary artery enlargement as a response to arteriosclerosis, to assess intermediate lesions, to reveal occult left main stem disease, and angiographically "silent" arteriosclerosis. In conjunction with the estimation of intracoronary flow reserve, patients with the diagnosis of coronary "syndrome X" can be better classified into those with or without early signs of arteriosclerosis. Additionally, IVUS is at present the only method allowing the classification of coronary artery lesions according to the AHA/ACC Stary classification. The intervention associated potentials of IVUS are the ability to allow optimal device selection, i.e. rotablators in calcified lesions or atherectomy devices in large plaque burden. The effects of PTCA on vessel wall morphology can be studied in great detail and the effect on luminal gain can be assessed almost on-line. The correlation between IVUS and angiography for estimation of luminal dimensions is inferior, because angiography is not able to describe complex luminal geometries. Several groups showed that the residual plaque area even after angiographically successful PTCA lies still in the range of 60%. A significant reduction of this number may influence long-term outcome after PTCA. Minimal luminal areas and residual plaque area after PTCA seem to be an indicator of restenosis, while the presence or absence of dissections seem to be less predictive. Additionally, the main mechanism of restenosis after PTCA is vessel shrinkage, not intimal hyperplasia. Intravascular monitoring of stent expansion led to high-pressure stent deployment with significant increase in post-procedural luminal diameters and finally the ability to withhold anticoagulation in patients with optimal stent deployment and to lower subacute stent thrombosis rates. First results for IVUS guided PTCA show a superior gain in post procedural free lumen without an increased complication rate. In the future, integrated devices, like balloons on IVUS catheters, steerable catheters, integrated flow and pressure transducers, tissue characterisation, and 0.018 inch IVUS guidewires will further enhance the usefulness of IVUS.

Role of intravascular ultrasound in the evaluation of mechanisms of coronary interventions and restenosis

Intravascular ultrasound (IVUS) has emerged from being a research tool to becoming an intrinsic part of modern invasive cardiology. The main reason is its ability to obtain “in vivo” microanatomy. For the first time it is possible to base decisions not only on lumenograms but also on vessel wall assessment. The intervention-associated potential of IVUS includes the ability to allow optimal device selection, i.e., rotablators in calcified lesions or atherectomy devices in large plaque burden. The effects of percutaneous transluminal coronary angioplasty (PTCA) on vessel-wall morphology can be studied in great detail and the effect on luminal gain can be assessed almost on-line. Several groups have showed that the residual plaque area, even after angiographically successful PTCA, still lies in the range of 60%. A significant reduction of this percentage may influence long-term outcome after PTCA. Minimal luminal areas and residual plaque area after PTCA seem to be an indicator of restenosis, whereas the presence or absence of dissections seem to be less predictive. The main mechanism of restenosis after PTCA is vessel shrinkage, not intimal hyperplasia. Intravascular monitoring of stent expansion led to high-pressure stent deployment with a significant increase in postprocedural luminal diameters and finally the ability to withhold anticoagulation in patients with optimal stent deployment.

Early and intermediate term clinical outcome after multiple coronary stenting.

To examine the immediate and intermediate term clinical outcome of multiple coronary stenting. Consecutive patients were prospectively entered on a dedicated database. Follow up information was obtained from outpatient and telephone interviews with patients and family physicians. A tertiary referral centre. 140 consecutive patients underwent multiple coronary stenting between April 1994 and November 1996. Most patients had unstable coronary syndromes. Death, cerebrovascular accidents, myocardial infarction (MI), coronary artery bypass surgery (CABG), and repeat angioplasty (PTCA). The angiographic success rate was 100% and the clinical procedural success rate 93%. The mean (SD) follow up was 11.9 (7.2) months (range 2-32). The mean (SD) number of stents per patient was 2.4 (0.7). The mean (SD) number of lesions treated per patient was 1.4 (0.6). There were four in-hospital deaths (2.9%) and five patients (3.6%) had an MI before hospital discharge. All in-hospital deaths occurred in patients presenting with an acute MI and cardiogenic shock. Three patients (2.2%) had a late MI. One patient with stent thrombosis underwent emergency CABG. Three patients (2.2%) underwent late CABG. Eight patients (5.7%) had a repeat PTCA. Eighty three patients (61.5%) were asymptomatic at follow up and 121 (86.4%) were free from major clinical events. In an era of increased operator experience, high pressure stent deployment, and reduced anticoagulation with antiplatelet treatment alone, multiple coronary stenting may be performed with a high procedural success rate and good intermediate term outcome.

Initial Results after Implantation of Coronary Artery Stents with Antiplatelet Agents

Backgound：The placement of stents in coronary arteries has been shown to reduce acute closure and restenosis in comparison to balloon angioplasty. However, clinical use of intracoronary stents is impeded by the subacute stent thrombosis and hemorrhagic complications associated with the anticoagulant regimen. It’ s known that the complete stent deployment with high pressure inflation and new antiplatelet agents are effective in reduction of subacute thrombosis and hemorrhage. So we evaluated initial results (success and complication rate after high pressure-stent deployment with new anticoagulation protocol. Methods：One hundred and ninety one patients with 201 lesions were treated with 231 stents of various types. The high pressure balloon inflation and antiplatelets agents were used in all cases. Final high pressure balloon inflation guided by IVUS were performed in 23 consecutive cases with incomplete stent deployment according to angiographic findings. Results：1 The indications of stenting (n＝210 were De novo in 124 (59%, bailout procedure in 57 (27%, suboptimal result after PTCA in 19 (8%, and restenosis after PTCA in 14 (6%. The location of lesions were LAD in 101, RCA in 67, circumflex in 28, ramus intermedius in 3, and LMT artery in 2 lesions. Angiographic morphologic characteristics were type A in 2, type B in 158 (B1：57, B2：101, and type C in 22 lesions. 2 The angiographic and clinical success rate was 96% (192/201 and 92% (186/201 respectively. 3 In angiographic analysis, the baseline average reference vessel dirmeter was 3.33±0.35 mm. Baseline minimum lumen diameter(MLD was 0.58±0.29 mm, with baseline percent diameter stenosis of 82.86±8.64%. The final stent diameter was 3.37±0.29 mm, with mean final percent stenosis of 0.63±8.25. The mean MLD after stenting was significantly increased (p 12atm (p<0.001. The length of lesions in GR Ⅰ (cook, GR Ⅱ, and Micro Ⅱ stents were significantly longer than ones in PS, Cordis, Wiktor, Nir (p<0.001. 4 In intravascular ultrasound analysis, the mean lumen CSA at the tightest point within stent increased 11%, from 8.4±2.4 mm 2 at the intial intravascular ultrasound to 9.4±2.1 mm 2 at the final intravascular ultrasound (p<0.001. 5 The procedural andpostprocedural complications were 2 acute closures associated with AMI and emergent CABG, 1 subacute closure which was revascularized by bail out stenting, 5 major hemorrhage requiring transfusion associated with 1 CVA and 2 metabolic acidosis induced by acute renal failure, and 5

Multiple stent implantation in single coronary arteries: acute results and six-month angiographic follow-up.

A total of 147 stents were implanted (in overlapping manner in 76% of vessels) in a single coronary artery in 59 patients (60 vessels, 97 lesions, 2.45 stents/vessel) over a period of 18 mo using high pressure stent deployment without ultrasound guidance. The indications for stenting were suboptimal percutaneous transluminal coronary angioplasty (PTCA) result (45%), primary prevention of restenosis (44%), acute closure (10%), and restenosis after plain balloon angioplasty (1%). One patient required emergency coronary artery bypass grafting (CABG) (extensive dissection), and one required early intervention with plain balloon angioplasty and intracoronary urokinase for stent thrombosis. There were no deaths. Thirteen patients had recurrence of angina within 6 mo and angiograms were performed in all. These showed intrastent restenosis in nine (all had successful repeat plain balloon angioplasty), development of new disease in other vessels along with restenosis close to the stent in the target vessel in one (underwent elective CABG) and normal angiograms with widely patent stents in three. Forty-five patients (77%) remained free of recurrent angina and 25 of these had follow-up angiograms (56%) at a mean of 172 days, two showing restenosis. Thus, the restenosis rate per patient in the symptomatic group (angiographic follow-up in 100%) was 77% and in the asymptomatic group (angiographic follow-up in 56%) was 8%. The restenosis rate in the subgroup with bailout stenting (n = 6) was 20% (angiographic follow-up in 83%). The overall restenosis rate per patient was 32% (overall angiographic follow-up in 66%). During the 6-mo follow-up period, one patient underwent elective CABG (1.7%), one sustained a non-Q myocardial infarction (1.7%), nine had repeat PTCA to the target vessel (15.5%), and there were no deaths. The event-free survival rate was 77%. Multiple stent implantation aided by high pressure stent deployment without ultrasound guidance and with adjunctive optimal antiplatelet therapy without oral anticoagulation seems to be a useful and effective revascularisation strategy to deal with long lesions and acute dissections with a high procedural success rate. The restenosis rate is acceptable and is not appreciably high as reported in previous studies from the "warfarin era."

Safety and Efficacy of Angiographic Guided Elective Palmaz‐Schatz Stent Implantation Without Coumadin: Comparison of Stent Implantation and Angioplasty

This study was designed to evaluate the safety and efficacy of routine high‐pressure Palmaz‐Schatz coronary stenting in patients with symptomatic coronary heart disease with only angiographic guidance without coumadin for poststenting treatment. Intracoronary stenting reduces restenosis rate after coronary angioplasty. High pressure stent deployment with intravascular ultrasound guidance reduces the incidence of stent thrombosis, despite reduction of anticoagulation. However, the feasibility of routine stent implantation with only angiographic guidance and without coumadin for poststenting treatment has not yet been determined. Patients undergoing coronary angioplasty for symptomatic coronary heart disease received stent implantation for abrupt or threatening vessel occlusion, vessel dissection without compromised antegrade blood flow (but at high risk for subacute occlusion and early restenosis), unsatisfactory angioplasty result with &gt; 30% residual stenosis, and elective stent implantation in de novo lesions, restenotic lesions, and lesions in bypass grafts. Quantitative coronary analysis was performed before the procedure, immediately after, and at follow‐up 6 ± 1 (SD) months later. This patient group was matched for clinical and angiographic characteristics with those patients who underwent balloon angioplasty during the same period. Patients who underwent coronary stenting had larger net gain (1.95 ± 1.0 vs 1.42 ± 0.9; P &lt; 0.001) resulting in a larger minimal luminal diameter (2.48 ± 1.19 vs 1.78 ± 1.01; P &lt; 0.001) at follow‐up as compared with balloon angioplasty. Restenosis, defined as &gt; 50% diameter stenosis at follow‐up, occurred in 35.0% in the PTCA group and in 16.1% in the stent group (P &lt; 0.001). Subacute stent thrombosis occured in one patient (0.8%) due to angiographically evident suboptimal stent expansion. Routine coronary high pressure Palmaz‐Schatz stenting with angiographie guidance without coumadin for poststenting treatment represents a safe and effective option in patients with symptomatic coronary heart disease without increasing the incidence of (sub)acute stent thrombosis.

Vessel tearing at the edge of intracoronary stents detected with intravascular ultrasound imaging

Stent deployment strategies have changed significantly in the past 2 yr, with “high-pressure” balloon inflations postdilatation being performed in the large majority of cases. There is currently little information about the effects of high pressure on the geometry of stent expansion and on the adjacent areas of the vessel wall. Intravascular ultrasound (IVUS) imaging is well-suited to investigate these issues, since it provides information not only about stent expansion and apposition but also about adjacent vessel-wall morphology at transition points such as the articulation site of the stent and the stent borders. We report on the results of a cohort of 30 consecutive stent cases which were systematically examined by IVUS following high-pressure inflation. All deployments were deemed successful by angiographic inspection. However, in 6 cases, intimal disruptions or “edge tears” were noted at the stent borders by IVUS. In 5 cases, edge tears were seen to occur at the distal border, whereas in one case edge tears were seen at both the proximal and distal edges of the stent. No angiographic and sonographic parameters were different except percent plaque area at the stent margins, which was significantly higher (53 ± 11%) in the lesions with edge tears, compared to 40 ± 10% plaque area in the group without evidence of pocket flaps (P = 0.007). This experience suggests that intimal disruptions or “edge tears” are a relatively common occurrence following high-pressure stent deployment, and may be related to the extent of marginal dissections. Cathet. Cardiovasc. Diagn. 40:152–155, 1997. © 1997 Wiley-Liss, Inc.

Vessel tearing at the edge of intracoronary stents detected with intravascular ultrasound imaging

Stent deployment strategies have changed significantly in the past 2 yr, with "high-pressure" balloon inflations postdilatation being performed in the large majority of cases. There is currently little information about the effects of high pressure on the geometry of stent expansion and on the adjacent areas of the vessel wall. Intravascular ultrasound (IVUS) imaging is well-suited to investigate these issues, since it provides information not only about stent expansion and apposition but also about adjacent vessel-wall morphology at transition points such as the articulation site of the stent and the the stent borders. We report on the results of a cohort of 30 consecutive stent cases which were systematically examined by IVUS following high-pressure inflation. All deployments were deemed successful by angiographic inspection. However, in 6 cases, intimal disruptions or "edge tears" were noted at the stent borders by IVUS. In 5 cases, edge tears were seen to occur at the distal border, whereas in one case edge tears were seen at both the proximal and distal edges of the stent. No angiographic and sonographic parameters were different except percent plaque area at the stent margins, which was significantly higher (53 +/- 11%) in the lesions with edge tears, compared to 40 +/- 10% plaque area in the group without evidence of pocket flaps (P = 0.007). This experience suggests that intimal disruptions or "edge tears" are a relatively common occurrence following high-pressure stent deployment, and may be related to the extent of marginal dissections.

Subacute Stent Thrombosis in the Era of Intravascular Ultrasound-Guided Coronary Stenting Without Anticoagulation: Frequency, Predictors and Clinical Outcome

Objectives. This study was performed to determine predictors of subacute stent thrombosis (SST) in the era of intravascular ultrasound (IVUS)-guided coronary stenting without anticoagulation.Background. The incidence of stent thrombosis has declined with the application of high pressure stent deployment with only antiplatelet therapy. However, no data are available on predictors of stent thrombosis in this era.Methods. Between March 30, 1993 and July 31, 1995, 1,042 consecutive patients underwent coronary stenting without anticoagulation. For this analysis, we excluded patients who underwent coronary artery bypass surgery, died or had acute stent thrombosis within the 1st 24 h after stenting (41 patients). A total of 1,001 patients (1,334 lesions) were included: 982 patients (1,315 lesions) without SST and 19 patients (19 lesions) with SST.Results. The rate of SST was 1.9% (per patient). There was no difference between the SST and No SST groups in rescue stenting (12% vs. 13.5%, p = 1.0) or mean ± SD reference diameter (3.11 ± 0.58 vs. 3.19 ± 0.53 mm, p = 0.54). A preexisting thrombus was present in 12% of the SST group and in 4.5% of the No SST group (p = 0.19). Predictors of SST by univariate analysis were low ejection fraction (p = 0.004), more stents per lesion (p = 0.049), use of combination of different stents (p = 0.012), smaller balloon size (p = 0.012) and suboptimal result in terms of smaller lumen dimensions by angiography (p = 0.016) and IVUS (p = 0.004), residual dissections (p = 0.027) and slow flow (p = 0.0001). In stepwise logistic regression analysis, ejection fraction (p = 0.019), use of a combination of different stents (p = 0.013) and postprocedure dissections (p = 0.014) and slow flow (p = 0.0001) were predictive of SST.Conclusions. In the present era of stent implantation, factors that may predispose to SST are low ejection fraction, intraprocedural complications leading to utilization of more stents, particularly with different stent designs, and suboptimal final result in terms of smaller lumen dimensions and persistent slow flow and dissections.(J Am Coll Cardiol 1997;29:6–12)>