Distal Embolization Of Thrombus Research Articles

Mitigating the risk of flow deterioration by deferring stent optimization in STEMI patients with large thrombus burden: Insights from a prospective cohort study

ObjectivesIt is uncertain, if omitting post-dilatation and stent oversizing (stent optimization) is safe and may decrease the risk for distal thrombus embolization (DTE) in STEMI patients with large thrombus burden (LTB).BackgroundIn patients with ST-segment elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (pPCI) with stenting, (DTE) and flow deterioration are common and increase infarct size leading to worse outcomes.MethodsFrom a prospective registry, 74 consecutive STEMI patients with LTB undergoing pPCI with stenting and intentionally deferred stent optimization were analyzed. Imaging data and outcomes up to 2 years follow-up were analyzed.ResultsOverall, 74 patients (18% females) underwent deferred stent optimization. Direct stenting was performed in 13 (18%) patients. No major complications occurred during pPCI. Staged stent optimization was performed after a median of 4 (interquartile range (IQR) 3; 7) days. On optical coherence tomography, under-expansion and residual thrombus were present in 59 (80%) and 27 (36%) cases, respectively. During deferred stent optimization, we encountered no case of flow deterioration (slow or no-reflow) or side branch occlusion. Minimal lumen area (mm2) and stent expansion (%) were corrected from 4.87±1.86mm to 6.82±2.36mm (p<0.05) and from 69±18% to 91±12% (p<0.001), respectively. During follow-up, 1 patient (1.4%) required target lesion revascularization and 1 (1.4%) patient succumbed from cardiovascular death.ConclusionsAmong STEMI patients with LTB, deferring stent optimization in the setting of pPCI appears safe and potentially mitigates the risk of DTE. The impact of this approach on infarct size and clinical outcomes warrants further investigation in a dedicated trial.

“Floating” Stent in a Coronary Aneurysm Presenting as ST-Elevation Myocardial Infarction

Coronary artery aneurysm (CAA) presenting as an ST-elevation myocardial infarction (STEMI) represents a clinical challenge due to the technical difficulties in the percutaneous management of this specific situation. Appropriate treatment for CAA depends on the precise clinical situation and consists of medical management, surgical resection, or/and stent placement. The high rate of complications during percutaneous intervention (distal thrombus embolization, no-reflow phenomenon, stent malposition, or dissection) makes emergent surgery a frequent situation in these cases. We present the case of a 50-year-old man with a STEMI due to thrombotic occlusion of CAA. Specific angiographic techniques and intracoronary imaging help with the percutaneous management of acute thrombotic occlusions in CAA, providing a less invasive approach than emergent surgery.

Treatment and Outcome of Patients With Coronary Artery Ectasia: Current Evidence and Novel Opportunities for an Old Dilemma.

Coronary artery ectasia (CAE) is defined as a diffuse or focal dilation of an epicardial coronary artery, which diameter exceeds by at least 1. 5 times the normal adjacent segment. The term ectasia refers to a diffuse dilation, involving more than 50% of the length of the vessel, while the term aneurysm defines a focal vessel dilation. CAE is a relatively uncommon angiographic finding and its prevalence ranges between 0.3 and 5% of patients undergoing coronary angiography. Although its pathophysiology is still unclear, atherosclerosis seems to be the underlying mechanism in most cases. The prognostic role of CAE is also controversial, but previous studies reported a high risk of cardiovascular events and mortality in these patients after percutaneous coronary intervention. Despite the availability of different options for the interventional management of patients with CAE, including covered stent implantation and stent-assisted coil embolization, there is no one standard approach, as therapy is tailored to the individual patient. The abnormal coronary dilation, often associated with high thrombus burden in the setting of acute coronary syndromes, makes the interventional treatment of CAE patients challenging and often complicated by distal thrombus embolization and stent malapposition. Moreover, the optimal antithrombotic therapy is debated and includes dual antiplatelet therapy, anticoagulation, or a combination of them. In this review we aimed to provide an overview of the pathophysiology, classification, clinical presentation, natural history, and management of patients with CAE, with a focus on the challenges for both clinical and interventional cardiologists in daily clinical practice.

Safety and Efficacy of Tirofiban During Mechanical Thrombectomy for Stroke Patients with Preceding Intravenous Thrombolysis.

PurposeWhether tirofiban is safe and effective for acute ischemic stroke (AIS) patients undergoing mechanical thrombectomy (MT) with preceding intravenous thrombolysis (IVT) remains unclear. We aim to evaluate the safety and efficacy of tirofiban during MT for patients with preceding IVT.Patients and MethodsPatients who underwent MT and preceding IVT were derived from the ANGEL registry and were dichotomized into tirofiban and non-tirofiban group according to whether rescue tirofiban was performed. The safety endpoints were sICH, total ICH and distal embolization. The efficacy endpoints were arterial recanalization, three-month functional independence (modified Rankin Scale [mRS]: 0–2) and mortality.ResultsWe included 207 MT patients with preceding IVT from the entire registry. Among them, there were 55 in tirofiban group and 152 in non-tirofiban group, and 17 (8.2%) patients suffered sICH and 36 (17.4%) suffered ICH within 24 hours post-MT; 11 (5.3%) distal embolization of thrombus; 111 (53.6%) achieved functional independence and 34 (16.4%) died after three-month follow-up. No significant differences in safety outcomes on sICH, ICH and distal embolization of thrombus and efficacy outcomes on recanalization and long-term functional independence were found between tirofiban and non-tirofiban group for the entire cohort (p>0.05 for all groups). Tirofiban was correlated with long-term mortality reduction for patients underwent MT and preceding IVT (adjusted hazard ratio 0.28 [0.08–0.94], adjusted p=0.03).ConclusionIn AIS patients who underwent MT and preceding IVT, rescue tirofiban was not correlated with increased risk of safety endpoints on sICH, ICH or distal embolization of thrombus, and might be associated with a lower risk of long-term mortality. Further study is needed to confirm the effect of early antiplatelet therapy with tirofiban for patients underwent MT and preceding IVT.

Thrombus aspiration in acute myocardial infarction: concepts, clinical trials, and current guidelines.

The pathogenesis that underlies acute myocardial infarction is complex and multifactorial. One of the most important components, however, is the role of thrombus formation following atherosclerotic plaque rupture, leading to sudden coronary occlusion and subsequent ischemia and infarction. Thrombus aspiration provides the opportunity of intracoronary clot extraction with the aim to improve coronary and myocardial perfusion, by reducing the risk of no-reflow secondary to distal embolization of thrombus. The utility of thrombus aspiration during primary percutaneous coronary intervention has been assessed in an increasing number of observational and randomized studies. This article reviews the contemporary data and provides insights into the validity of thrombus aspiration in the setting of acute myocardial infarction.

Thrombus aspiration in acute myocardial infarction.

The success of primary percutaneous coronary intervention (PCI) in patients with ST-segment elevation myocardial infarction (STEMI) is often hampered by incomplete microvascular myocardial reperfusion owing to distal embolization of thrombus resulting in microvascular obstruction. To address this problem, thrombus aspiration devices have been developed that can be used to evacuate coronary thrombus either manually or mechanically. Thrombus aspiration has the potential to reduce the local thrombus load, minimize the need for balloon predilatation, facilitate direct stenting, prevent distal embolization, and ultimately improve myocardial reperfusion. Furthermore, thrombus aspiration has enabled us to study coronary thrombus in vivo, and has facilitated recognition of distinct mechanisms of coronary thrombosis. Clinical trials focusing on manual thrombus aspiration in primary PCI have generally shown improved myocardial reperfusion. However, in two large trials powered for clinical end points, no reduction in 1-year mortality or other adverse clinical events was observed with the use of this strategy. Moreover, one of these trials showed a marginally increased risk of stroke. Consequently, current guidelines do not recommend routine use of thrombus aspiration. Future studies should focus on the identification of subgroups of patients with STEMI who might derive benefit from manual thrombus aspiration, and establish the effect of operator performance on the efficacy and safety of the procedure.

Real world comparison of the MGuard Stent versus the bare metal stent for ST Elevation myocardial infarction (The REWARD‐MI study)

The MGuard Stent (MGS) was designed to prevent distal embolization of thrombus and has been shown to improve microcirculation in ST-elevation myocardial infarction (STEMI). However, there are no real world data comparing it with the bare metal stent (BMS). The aim of this study is to determine the efficacy and safety of the MGS in STEMI in the real world compared to the BMS. In total, 262 patients were included from a single centre, of which 35.9% had an MGS implanted. Two groups of 79 patients were established after propensity score matching, and they were similar in terms of baseline and periprocedural variables. The mean follow-up was 321 ± 12.94 days. There was no difference in mortality (7.6% in both groups), major adverse cardiac events (20.3% vs. 12.7%, P = 0.198), non-cardiac mortality, or non-fatal myocardial infarction (6.3% in both groups). Target lesion revascularization (TLR) was significantly higher in the MGS group (11.4% (9) vs. 1.3% (1) P < 0.01; RR 10.02 [1.23-81.16]). Our study is the first to compare the MGS with the BMS in STEMI in the real world, and it also appears to confirm that although the MGS is a safe device in STEMI that is not associated with increased mortality, it is associated with a higher long-term TLR rate. © 2014 Wiley Periodicals, Inc.

TCTAP A-015 Required Multiple Aspiration Is the Sign of High Risk of Distal Embolization in Acute Myocardial Infarction

Slow-flow/no re-flow phenomenon is mainly induced by distal embolization of thrombus and necrotic core during PCI of AMI, and is associated with unfavorable long-term clinical outcomes. Firstly, we perform aspiration thrombectomy for AMI patients, but we will sometimes experience slow flow or no re-

Otvaranje koronarne arterije u primarnim PCI ne znači uvek i optimalni protok i najpovoljniji ishod za bolesnika - tretman 'no reflow' fenomena

Microvascular obstruction (MVO) commonly occurs following percutaneous coronary interventions (PCI), may lead to myocardial injury, and is an independent predictor of adverse outcome. Severe MVO may manifest angiographically as reduced flow in the patent upstream epicardial arteries, a situation that is termed 'no-reflow.' The no-reflow phenomenon was originally observed in experimental models of acute myocardial infarction (MI) and was described as a failure to restore normal myocardial blood flow despite removal of the coronary obstruction. Defined angiographically, no-reflow manifests as an acute reduction in coronary flow (TIMI grade 0-1) in the absence of dissection, thrombus, spasm, or high-grade residual stenosis at the original target lesion. Lesser degrees of flow impairment (TIMI grade 2) are generally referred to as 'slow-flow'. However, studies of acute MI patients have reported that scintigraphic evidence for no-reflow may occur in the absence of angiographic slow-flow, suggesting that microvascular injury may be angiographically inapparent in some patients. The mechanisms and mediators responsible for noreflow remain speculative, but the end result appears to be severe microvascular dysfunction. Potential mechanisms of microvascular dysfunction include vasospasm, distal embolization of thrombus or other debris, oxygen free radical mediated endothelial injury, capillary plugging by erythrocytes and neutrophils, and intracellular/interstitial edema with intramural hemorrhage. Microvascular obstruction can be broadly categorized according to the duration of myocardial ischemia preceding PCI. In 'interventional MVO' (e.g., elective PCI), obstruction typically involves myocardium that was not exposed to acute ischemia before PCI. Conversely 'reperfusion MVO' (e.g., primary PCI for acute myocardial infarction) occurs within a myocardial territory that was ischemic before the coronary intervention. Interventional and reperfusion MVO have distinct pathophysiological mechanisms and may require individualized therapeutic approaches. Interventional MVO is triggered predominantly by downstream embolization of atherosclerotic material from the epicardial vessel wall into the distal microvasculature. Reperfusion MVO results from both distal embolization and ischemia-reperfusion injury within the subtended ischemic tissue. Randomized clinical trials have studied strategies for prevention of MVO and no-reflow; however, the efficacy of measures for reversing MVO once no-reflow has been demonstrated angiographically is unclear. New approaches for prevention and treatment of MVO will require a better understanding of intracellular cardioprotective pathways such as the blockade of the mitochondrial permeability transition pore.

Abstract 213: Retrieval of Plaque Debris by Aspiration Thrombectomy is the Sign of High Risk for Distal Embolization in Acute Coronary Syndrome Patients

Background: Slow flow or no re-flow phenomenon during coronary intervention is mainly caused by distal embolization of thrombus and plaque debris, and is associated with unfavorable long-term clinical outcomes. However, its high-risk patients are not well understood. Aspiration thrombectomy in the patients with acute coronary syndrome (ACS) often retrieves thrombus but sometimes plaque debris. Therefore, we examined if the ACS patients in whom plaque debris was retrieved by aspiration thrombectomy were high-risk of distal embolization. Methods: Consecutive patients with ACS (n=151) who received aspiration thrombectomy and coronary intervention with filter-type distal protection device (Filtrap) were prospectively enrolled. We classified them into two groups according to whether (Group A, n=29) or not (Group B, n=122) the plaque debris was retrieved by aspiration thrombectomy. We compared between the groups the frequency of filter slow flow/ no-reflow phenomenon and the frequency of distal embolization captured by filter device. Results: Distal embolization of plaque debris was detected more frequently in Group A than in Group B (90% vs. 30%, P&lt;0.0001). Filter slow flow/ no-reflow phenomenon occurred more frequently in Group A than in Group B (93% vs. 29%, P&lt;0.0001). Conclusion: Retrieval of plaque debris by aspiration thrombectomy is the sign of high risk for distal embolization in ACS patients. Distal protection may potentially be useful for those high-risk patients.

Treating thrombus in the coronary arteries

Primary percutaneous coronary intervention (PCI) has greatly improved outcomes in patients with ST-elevation myocardial infarction (STEMI) and has, therefore, become the preferred reperfusion strategy for this patient group. The goal of primary PCI is to achieve a thrombolysis in myocardial infarction (TIMI) 3 flow and also to restore adequate perfusion at the myocardial level. Distal thrombus embolization during primary PCI occurs frequently and is also associated with compromised long-term outcomes. In this article, we provide an overview of the treatment of thrombus and the role of thrombectomy in PCI for STEMI.

Closed versus open cell stent for high-risk percutaneous coronary interventions in ST-elevation acute myocardial infarction: The Closed versus Open Cells stent for High risk percutaneous coronary Interventions in ST-Elevation acute myocardial infarction (COCHISE) pilot study

Stent deployment may be associated with distal embolization and slow flow in coronary thrombotic lesions. There are no data on the risk of distal thrombus embolization according to the stent design. The aim was to evaluate coronary flow after percutaneous coronary interventions (PCI) in acute myocardial infarction according to the employed stent (closed versus open cell design). From March 2010 to December 2011, 223 consecutive patients with acute ST-elevation myocardial infarction were randomized to primary PCI either with an open cell (112 patients, 88 men) or with a closed cell stent design (111 patients, 92 men). The primary endpoint was the corrected TIMI frame count (cTFC) after the procedure. There were no significant differences in procedural success nor in-stent deployment in the 2 groups. At baseline, there were no significant differences in cTFC between the 2 groups (70 ± 37 and 67 ± 39, P = .65, respectively). After the procedure, the open cell group showed significantly higher cTFC compared to the closed cell group (18 ± 11 and 15 ± 5, P = .003 respectively). This difference was associated with a significant lower rate of TIMI 3 flow (87% and 95%, P = .037) and myocardial blush grade 3 (65% and 87%, P = .001) in the open compared to the closed cell group. There were 2 cases of death in the open cell and 1 case in the closed cell group. The use of a closed cell stent design rather than an open cell during PCI for acute ST-elevation myocardial infarction is associated with better coronary angiographic flow after PCI.

Simple aspiration in acute myocardial infarction: too simple to be true?

This editorial refers to ‘Impact of thrombus aspiration during primary percutaneous coronary intervention on mortality in ST-segment elevation myocardial infarction’†, by A. Noman et al. , on page 3054 Primary percutaneous coronary intervention (PCI) in ST-segment elevation myocardial infarction (STEMI) has contributed to dramatic declines in cardiovascular mortality over the last three decades.1 Nonetheless, normal myocardial perfusion is not restored in approximately one-third of patients after primary PCI, prompting investigation of novel drugs, technologies, and approaches to improve reperfusion success further. While numerous mechanisms may contribute to reperfusion failure, distal embolization of thrombus and friable atheromatous debris is believed to be ubiquitous during primary PCI, and results in microvascular obstruction.2 Preventing embolization is therefore intuitive, and theoretically should result in improved reperfusion success as measured angiographically (better epicardial and myocardial blood flow), electrocardiographically [increased ST-segment resolution (STR)], functionally (greater myocardial salvage with reduced infarct size), and clinically (enhanced survival free from heart failure events). Four types of devices have been developed to prevent embolization during PCI: distal embolic protection catheters; ‘active’ vacuum-type thrombectomy systems; manual aspiration; and micronet mesh-covered stents (the latter of which is currently undergoing investigation). Despite their innate appeal, in randomized trials distal embolic protection devices and active thrombectomy systems have surprisingly not been shown to be beneficial.3 In contrast, outcomes with ‘simple’ aspiration systems in which intracoronary thrombus is extracted through a hollow catheter prior to stent implantation have been more favourable, although not uniformly so. In TAPAS, the largest such randomized trial to date, aspiration resulted in modestly better rates of myocardial blush [without improving TIMI (Thrombolysis in Myocardial Infarction) flow or preventing macroscopic coronary thrombo-emboli] and STR, with a trend toward improved 30-day survival which became significant by 1 year.4,5 However, other trials have reported conflicting or negative results, …

Thrombus Extraction Catheters vs. Angiojet Rheolytic Thrombectomy in Thrombotic Lesions/SV Grafts

Primary percutaneous coronary intervention, (pPCI), of native coronaries and saphenous vein grafts (SVGs), is the recommended reperfusion strategy for STEMI, and an early invasive approach is recommended for high risk patients with UA/NSTEMI. Although PCI effectively restores flow in the infarct related artery/culprit vessel in both situations, myocardial perfusion often remains suboptimal due to microvascular obstruction, partly attributed to distal embolization of thrombus. Hence, thrombectomy (manual or mechanical), prior to stenting may further reduce hard clinical end points in patients with ACS. This article discusses accumulated evidence regarding the safety and effectiveness of thrombectomy in culprit native coronaries and SVGs in such patients, as well as possible strategies for maximizing its benefits relative to the size of the thrombotic burden.

Aspiration of embolized thrombus during primary percutaneous coronary intervention

During percutaneous coronary intervention for acute myocardial infarction, distal embolization of thrombus and plaque material often occurs, despite the use of thrombectomy and aspiration catheters. Large embolized thrombi can cause occlusion of distal coronary vessels for which angioplasty most often leads to no more than poor results. We describe the successful use of an aspiration catheter to treat distally embolized thrombus, to optimize coronary reperfusion therapy, and to improve salvage of myocardial tissue. We discuss the manifestation and incidence of distal embolization and show its clinical relevance.

Does Thrombus Aspiration Improve Outcomes of Primary Percutaneous Coronary Intervention

Microvascular obstruction due to distal thrombus embolization during primary percutaneous coronary intervention impairs myocardial perfusion and is

Rheolytic Thrombectomy With Percutaneous Coronary Intervention for Infarct Size Reduction in Acute Myocardial Infarction: 30-Day Results From a Multicenter Randomized Study

The goal of this work was to determine whether rheolytic thrombectomy (RT) as an adjunct to primary percutaneous coronary intervention (PCI) reduces infarction size and improves myocardial perfusion during treatment of ST-segment elevation myocardial infarction (STEMI). Primary PCI for STEMI achieves brisk epicardial flow in most patients, but myocardial perfusion often remains suboptimal. Distal embolization of thrombus during treatment may be a contributing factor. This prospective, multicenter trial enrolled 480 patients presenting within 12 h of symptom onset and randomized to treatment with RT as an adjunct to PCI (n = 240) or to PCI alone (n = 240). Visible thrombus was not required. The primary end point was infarct size measured by sestamibi imaging at 14 to 28 days. Secondary end points included final Thrombolysis In Myocardial Infarction (TIMI) flow grade, tissue myocardial perfusion (TMP) blush, ST-segment resolution, and major adverse cardiac events (MACE), defined as the occurrence of death, new Q-wave myocardial infarction, emergent coronary artery bypass grafting, target lesion revascularization, stroke, or stent thrombosis at 30 days. Final infarct size was higher in the adjunct RT group compared with PCI alone (9.8 +/- 10.9% vs. 12.5 +/- 12.13%; p = 0.03). Final TIMI flow grade 3 was lower in the adjunct RT group (91.8% vs. 97.0% in the PCI alone group; p < 0.02), although fewer patients had baseline TIMI flow grade 3 in the adjunct RT group (44% vs. 63% in the PCI alone group; p < 0.05). There were no significant differences in TMP blush scores or ST-segment resolution. Thirty-day MACE was higher in the adjunct RT group (6.7% vs. 1.7% in the PCI alone group; p = 0.01), a difference primarily driven by very low mortality rate in patients treated with PCI alone (0.8% vs. 4.6% in patients treated with adjunct RT; p = 0.02). Despite effective thrombus removal, RT with primary PCI did not reduce infarct size or improve TIMI flow grade, TMP blush, ST-segment resolution, or 30-day MACE.

Inflammatory and vasoactive factors in the aspirate from the culprit coronary artery of patients with acute myocardial infarction

Background Besides distal embolization of thrombus and plaque debris, locally increased inflammatory markers at the site of ruptured plaque in acute myocardial infarction (AMI) are thought to have an adverse impact on myocardial reperfusion during primary percutaneous coronary intervention (PCI). However, there is lack of data on such factors. Therefore, we investigated the presence of locally increased inflammatory and vasoactive factors in culprit coronary artery. Methods We performed primary PCI with PercuSurge GuideWire system in 18 AMI patients. We collected blood samples from the femoral artery before PCI and from culprit coronary artery after first predilation while inflating the distal protection balloon and after completing PCI. We determined concentrations of C-reactive protein, soluble CD40 ligand, Interleukin (IL-6), serotonin, tissue factor, and factor VIIa. Results While the concentrations of soluble CD40 ligand (2.84 ± 3.74 vs 0.98 ± 0.63 ng/mL, p = 0.004), IL-6 (33.67 ± 32.63 vs 17.08 ± 21.41 pg/mL, p < 0.001), serotonin (2.05 ± 0.76 vs 0.92 ± 0.60 ng/mL, p < 0.001), tissue factor (257.17 ± 84.34 vs 154.60 ± 87.99 pg/mL, p < 0.001) and factor VIIa (34.30 ± 27.30 vs 24.19 ± 28.00 ng/mL, p = 0.016) were significantly higher in the culprit coronary artery than in the femoral artery, CRP levels did not differ. The locally elevated concentrations of various factors were successfully reduced after multiple aspirations of blood using the PercuSurge GuideWire system. Conclusions We found increased levels of soluble CD40 ligand, IL-6, serotonin, tissue factor and factor VII in the culprit coronary artery compared to those in peripheral blood. The clinical impact of such locally increased soluble factors in the culprit coronary artery needs to be investigated in further studies.

Usefulness of the rescue PT catheter to remove fresh thrombus from coronary arteries and bypass grafts in acute myocardial infarction

I the setting of an acute myocardial infarction (AMI), thrombolytic therapy has proved to reduce mortality and improve left ventricular function.1–3 A good or even better alternative is primary angioplasty.4–6 Several devices have been developed to remove thrombus material. The disadvantages of most of these devices are that they are complicated, and difficult to handle in the acute setting for interventionalists who are not experienced with these devices. We describe the clinical experience with a simple thrombectomy system using a catheter that can be handled like a balloon. This study evaluates the safety and efficacy of the Rescue percutaneous thrombectomy (PT) system (Boston Scientific, Maple Grove, Minnesota) in the setting of AMI or unstable angina pectoris. • • • The thrombectomy system consists of a very flexible, 4.5Fr polyethylene catheter that can be advanced over a standard 0.014-in guidewire through a 7Fr guiding catheter using a monorail system. The catheter has an oblique tip to facilitate passage through the lesion and a marker to improve visibility during fluoroscopy (Figure 1). The proximal end has an extension tube connected to a vacuum pump (0.8 bar) with a collection bottle. The removed thrombus material is collected on a filter in the collection bottle. While the catheter is advanced and pulled back through the thrombus, continuous suction is applied. When necessary, several runs can be performed. In case of distal embolization, the catheter can be advanced distally over the guidewire to remove the embolized material. Thrombectomy using the Rescue PT system was considered when a coronary angiogram recorded in the setting of an AMI raised the suspicion of a considerable amount of thrombus in a venous coronary artery bypass graft or native coronary artery. At the beginning of the procedure 10,000 IU of heparin was administered to the patients not pretreated with a thrombolytic agent. A coronary angiogram was performed before and after guidewire placement, after every passage of the Rescue PT catheter, and when applicable after additional coronary intervention. Coronary flow was classified according to the Thrombolysis In Myocardial Infarction (TIMI) trial.7 Angiographic analysis was performed to evaluate presence and removal of the thrombus and distal embolization. The removal of thrombus was also determined by the material on the filter in the collection bottle. The use of additional medication and coronary intervention, including stent placement, were at the discretion of the operator. Fifty-one lesions were treated in 50 patients (8 women and 42 men). One patient had a thrombus in the left anterior descending (LAD) artery and first diagonal branch because of distal embolization of thrombus from the proximal LAD artery after treatment with a thrombolytic agent. In 30 patients (60%) thrombectomy was performed after failed thrombolysis. In 43 patients (86%) the estimated age of the thrombus was ,6 hours, in 7 patients, thrombus age was 6 to 10 hours, and in 2 patients, it was .10 hours. In 45 patients thrombectomy was performed in a native coronary artery and in the remaining 5 patients in a venous coronary artery bypass graft (graft age range 13 to 18 years). The lesion could be reached in all vessels and thrombus material was removed from 48 of the 51 From the Department of Cardiology, University Hospital Maastricht, Maastricht; and Department of Cardiology, Catharina Ziekenhuis, Eindhoven, The Netherlands. Dr. van Ommen’s address is: Department of Cardiology, University Hospital Maastricht, PO Box 5800, 6202 Maastricht, The Netherlands. E-mail: vvo@scar.azm.nl. Manuscript received October 20, 2000; revised manuscript received and accepted February 27, 2001. FIGURE 1. Photograph of the tip of the Rescue PT system showing the oblique tip and the marker band.

Covered Stents for Vein-Graft Lesions

Stents frequently are used for the percutaneous treatment of lesions in saphenous vein grafts (SVGs). However, such use is associated with a high risk for distal thrombus embolization (resulting in MI) and with a lower benefit in reducing restenosis than that typically obtained with stent placement in native coronary arteries. In this …