Angiographic Evidence Of Thrombus Research Articles

PERIPHERAL ARTERY STENT THROMBOSIS: REPORT FROM THE EXCELLENCE IN PERIPHERAL ARTERY DISEASE (XLPAD) REGISTRY

There are limited data on infrainguinal peripheral artery stent thrombosis (ST). We analyzed procedures performed between May 2005-March 2014 enrolled in the XLPAD registry. Occurrence of ST was determined by acute onset of lower limb pain and angiographic evidence of thrombus. ST occurred in 27

Aspiration Thrombectomy During Primary Percutaneous Coronary Intervention as Adjunctive Therapy to Early (in‐ambulance) Abciximab Administration in Patients with Acute ST Elevation Myocardial Infarction: An Analysis from Leiden MISSION! Acute Myocardial Infarction Treatment Optimization Program

The benefits of early abciximab administration and thrombus aspiration in ST elevation myocardial infarction (STEMI) patients undergoing primary percutaneous coronary intervention (PPCI) have previously been elaborated. However, whether there is an adjunctive effect of thrombus aspiration among STEMI patients, with angiographic evidence of thrombus, receiving early prehospital abciximab remains unclear. In the context of a fixed protocol for PPCI, 158 consecutive patients with STEMI were enrolled, in whom abciximab was started early before hospital arrival (in-ambulance); 79 patients who had PPCI with thrombus aspiration (thrombectomy-facilitated PCI group), were compared to 79 who had PPCI without thrombus aspiration (conventional PCI group) in a prospective nonrandomized study. The primary end-point was complete ST-segment resolution within 90 minutes. Secondary end points included distal embolization, enzymatic infarct size as well as left ventricular ejection fraction (LVEF) assessed by gated single-photon emission computed tomography. Major adverse cardiac events (MACEs) were evaluated up to 12 months. Both groups were comparable for baseline characteristics. ST-segment resolution was significantly higher in the thrombectomy-facilitated group (P = 0.002), and multivariate analysis identified thrombectomy as an independent predictor of ST-segment resolution (OR = 9.4, 95% CI = 2.6-33.5, P = 0.001). Distal embolization was higher in the conventional PCI group among patients with higher thrombus grades. No difference was observed between both groups in infarct size assessed by peak creatine kinase (p = 0.689) and peak Tn-T levels (P = 0.435). Also, the LVEF at 3 months was similar (P = 0.957). At 12 month clinical follow-up, thrombus aspiration was, however, associated with reduced all-cause mortality (log-rank p = 0.032). Among STEMI patients treated with PPCI and in-ambulance abciximab, it appears that a selective strategy of thrombus aspiration still has additive benefit.

Tools & Techniques: Percutaneous intervention of saphenous vein graft lesions

© Europa Digital & Publishing 2013. All rights reserved. Background The percutaneous treatment of patients with obstructive atherosclerotic disease in coronary saphenous vein bypass grafts (SVG) remains a challenge in interventional cardiology. Patients undergoing SVG intervention are often older, and suffer significant comorbidities. Moreover, SVGs usually present a degenerated pattern of atherosclerosis, with complex, friable, thrombotic-prone lesions. SVG interventions carry a higher risk of acute complications, mainly distal embolisation, and poorer long-term outcomes, mainly restenosis, than do native coronary vessel interventions1,2. The predictors of one-month major cardiac events after SVG intervention have been explored recently3. The degree of SVG degeneration assessed by the SVG degeneration score, the estimated plaque volume, angiographic evidence of thrombus, and increasing patient age are the correlates associated with the 30-day composite outcome of death, myocardial infarction (MI) and target lesion revascularisation (TLR). Thus, an important reason for poorer outcomes of percutaneous coronary interventions (PCI) in SVGs is the embolisation of atherothrombotic debris into the native coronary circulation, often resulting in periprocedural MI or reduced antegrade flow (“no-reflow”). Strategies for addressing this distal embolisation problem include both proximal and distal protection devices, as well as adjunctive pharmacology and stenting approaches. Embolic protection devices have demonstrated value in decreasing the risk of embolisation and post-procedural myocardial enzyme elevation after SVG intervention. While stenting has definitely been proved to be superior to balloon-only angioplasty for the treatment of SVG lesions, the choice of the type of stent (bare metal stent versus drugeluting stent) is still a matter of debate. Drug-eluting stents appear promising for the successful sealing of SVG disease; however, available long-term safety and effectiveness data are conflicting and give reason for caution.

Aspiration coronary thrombectomy for acute myocardial infarction increases myocardial salvage

The aim of the study was to assess if aspiration thrombectomy in high risk patients with STEMI and angiographic evidence of thrombus may improve myocardial salvage. It is unclear if thrombus aspiration before percutaneous intervention (PCI) improves myocardial salvage. The trial was a prospective randomized study. The inclusion criteria were: first STEMI within 12 hr from symptoms onset, culprit lesion in left anterior descending or right coronary artery, culprit artery TIMI flow ≤ 2 and angiographic evidence of thrombus. The primary endpoint was myocardial salvage index (MSI) as assessed by (99m) Tc-sestamibi SPECT imaging. We randomized 137 patients (98 male, mean age 64.1 ± 12.5 years) either to aspiration thrombectomy followed by standard PCI with stent implantation (n = 67) or to standard primary PCI (n = 70). Index perfusion defect was similar in both study groups: 34.2% ± 13.1% in thrombectomy group versus 37.1% ± 12.0% in primary PCI group (P = 0.2). MSI was larger in aspiration thrombectomy group than in control patients [25.4% (IQR 13.5-44) vs. 18.5% (IQR 7.7-30.3) respectively, P = 0.02]. The final infarct size was smaller in patients treated with aspiration thrombectomy (23.1% ± 13.3% vs. 28.9% ± 10.2% in the control group, P = 0.002). Aspiration thrombectomy improves myocardial salvage in high risk STEMI patients with angiographic evidence of thrombus.

Thrombus aspiration in a series of patients with stable or unstable angina pectoris and lesion-site thrombus formation.

Background. In acute myocardial infarction, thrombus aspiration prior to percutaneous coronary interventions (PCI) is often beneficial, but this approach has never been studied in patients without acute myocardial infarction. The aim of this retrospective study is to shed light on that topic based on our initial experience with manual thrombus aspiration in patients with stable or unstable angina pectoris and angiographic evidence of lesion-site thrombus. Methods. We assessed the feasibility (thrombus aspiration without predilatation) of this approach; in addition, we determined angiographic coronary flow and myocardial blush grade. Results. During 33 months in which a total of 4725 PCI were performed in our centre, manual thrombus aspiration was attempted in 14 patients with stable or unstable angina pectoris with angiographic evidence of thrombus. In nine of these 14 patients, the aspiration catheter could be advanced into the lesion without predilatation; in eight patients visible thrombus was obtained. The corrected TIMI frame count improved during the entire interventional procedure (21.1±11.2 vs. 12.8±5.9 frames; p=0.015). Myocardial blush grade, which overall improved during PCI (p<0.001), tended to show greater improvement in patients in whom thrombus aspiration could be achieved (1.6±0.9 vs. 0.7±0.5; p=0.06). Conclusions. Preliminary evidence suggests that manual thrombus aspiration may occasionally be considered in selected patients without acute myocardial infarction but with angiographic evidence of lesion-site thrombus. Nevertheless, prospective studies are required to clearly define the role of this approach in clinical practice. (Neth Heart J 2010;18:423-9.).

Effect of High-Dose Intracoronary Adenosine Administration During Primary Percutaneous Coronary Intervention in Acute Myocardial Infarction: A Randomized Controlled Trial

Effect of High-Dose Intracoronary Adenosine Administration During Primary Percutaneous Coronary Intervention in Acute Myocardial Infarction: A Randomized Controlled Trial

Angiographic results of a Tacrolimus-eluting stent in acute coronary syndrome lesions

The Janus stent releases Tacrolimus from reservoirs located at the abluminal stent surface without any polymer. In stable coronary lesions the stent did not show relevant antiproliferative effects. Since Tacrolimus provides antiproliferative and antiinflammatory properties, we sought to investigate the efficacy of the Tacrolimus eluting Janus stent in acute coronary syndrome lesions with a more pronounced inflammatory cell reaction compared to stable coronary artery lesions. Patients with acute coronary syndrome (STEMI or NSTEMI) undergoing cardiac catheterization and stent implantation were enrolled in this prospective registry. Primary outcome measure was in-stent late lumen loss at 6 months. There were two pre-specified subgroups based on presence or absence of high-pressure post-dilation (HPPD) with a balloon >or= 0.25 mm larger than the delivery balloon. Sixty patients were enrolled. In 34 patients HPPD was performed. Reference diameter was 2.85+/-0.57 mm. Stented length was 30.8+/-23.8 mm in HPPD and 19.7+/-7.3 mm in non-HPPD group. For the total population in-stent late loss was 0.92+/-0.80 mm and binary restenosis rate 32.6%. Late loss (1.09+/-0.74 mm Vs. 0.64+/-0.83 mm) and binary restenosis rate (37.0% Vs. 25.0%) were higher in the HPPD subgroup compared to lesions in non-HPPD. The angiographic evidence of thrombus was associated with a higher late loss. Restenotic pattern was occlusive in 40%, diffuse in 33% and focal in 27%. The use of the Tacrolimus eluting Janus stent in acute coronary syndrome lesions was associated with a high late lumen loss, a high angiographic restenosis rate and a mainly occlusive or diffuse pattern of restenosis.

Stent thrombosis after sirolimus‐ and paclitaxel‐eluting stent implantation in daily clinical practice: Analysis of a single center registry

To evaluate stent thrombosis (ST) rate after sirolimus-eluting stent (SES) and paclitaxel-eluting stent (PES) implantation in daily clinical practice. The safety profile of drug-eluting stents (DES) was predominantly determined in randomized clinical trials with narrow inclusion criteria. Concerns about ST have been raised in unselected patients treated with DES. We prospectively evaluated 867 patients undergoing DES implantation, 618 patients with SES, and 249 with PES, in a single academic center. Multivessel disease was present in 72% of patients, multivessel stenting was performed in 17%, long (>18 mm) lesions were treated in 30%, and multiple stents per lesion were needed in 31%. On average, 1.7 +/- 0.8 stents per patient were implanted (stented segment length: 32 +/- 25 mm/vessel). IIb/IIIa inhibitors were used in 7.5%. Intravascular ultrasound (IVUS) guidance was employed in 65% of SES and 50% of PES implantations, and the procedural success rate was 100% in SES and 99% in PES cases. Six-month follow-up was performed in all patients, whereas one-year follow-up was completed in 87% patients of the SES group and in 95% of the PES group. We considered that ST occurred when angiographic evidence of thrombus was available, or when patients experienced sudden cardiac death or either ST-elevation or non-ST-elevation myocardial infarction (MI) through the 12-month follow-up period. The overall incidence of ST was 0.9% (0.4% in SES and 2% in PES, P = 0.03). Of the eight ST, two (25%) were acute, four (50%) subacute, one (12.5%) was a late event, and one (12.5%) a very late event. Seven ST were confirmed by angiography. No IVUS guidance was used in 4/8 (50%) ST patients, while antiplatelet therapy was prematurely discontinued in 3/8 (37.5%). Among ST patients, mortality and nonfatal MI rates were 25% and 37.5%, respectively. No ST was diagnosed between 6 and 12 months, while one very late thrombosis occurred at 15 months. The incidence of ST after DES use in daily clinical practice is low and similar to that observed in randomized clinical trials.

Primary angioplasty and routine utilization of thrombus aspiration devices: feasibility and results in a consecutive series of 486 patients

Primary percutaneous transluminal coronary angioplasty (PTCA) is the treatment of choice for acute ST-segment elevation myocardial infarction (STEMI) in high-volume centres with experienced operators, but is often limited by a suboptimal microvascular perfusion due to distal embolization and impaired myocardial perfusion. The present study investigates whether routine use of thrombus aspiration (TA) devices is feasible in daily practice, along with its safety and effectiveness. This study is based on a series of 486 consecutive STEMI patients treated at our single institution by the same three operators (from 2001 to 2005). They underwent primary PTCA with or without TA according to these angiographic features: infarct related artery (IRA) diameter>or=3 mm; thrombotic occlusion or angiographic evidence of thrombus; absence of severe proximal tortuosity or calcification. We evaluate the efficacy of TA in terms of procedural success, coronary thrombolysis in myocardial infarction (TIMI) flow, myocardial blush grade (MBG), resolution>or=50% of ST segment elevation, and clinical events during hospital stay and at 6-month follow-up. A total of 486 primary PTCAs were performed, 217 (44.6%) with TA as a first device using RESCUE (n=65), EXPORT (n=140) and DIVER-CE (n=12) catheters. In 141 (65%) cases, macroscopic material was aspirated. The patients submitted to TA were more often males (84.7% versus 71.7%, P<0.05) and younger (age: 61.02+/-11.91 versus 64.47+/-10.59 years, P<0.01) than patients treated with traditional PTCA and the IRA was more frequently occluded at angiography (basal TIMI 0: 70.5% versus 47.9%). Application of the TA did not increase the complexity of the procedure (door-to-balloon times, minutes of fluoroscopy and amount of dye). TA alone was effective to restore TIMI 3 flow in 187 cases (86.2%) as a first device and in three other cases (1.4%) after predilatation with balloon. Direct stenting without predilatation was possible in 144 cases (66.4%) after TA. TA was not effective in 27 cases (12.4%) and this subgroup had both angiographic and clinical unfavourable results in comparison with the effective TA group (final TIMI 1 in 11.1% versus 0.5%, P<0.015; final MBG 1 in 55.5% versus 9.5%, P<0.001; lack of ST segment resolution>or=50% in 44.4% versus 7.9%, P<0.001; in-hospital mortality 14.8% versus 2.6%, P<0.05 and mortality at 6 months 18.5% versus 3.1%, P<0.05). In the whole TA population, final TIMI 3 flow was achieved in 203 cases (93.5%), final MBG 3 in 145 cases (66.8%) and ST segment resolution>or=50% in 185 cases (85.2%), in-hospital mortality was 4.1% and cumulative mortality at 6-month follow-up was 5.5%. In our case series, 486 consecutive unselected patients with STEMI were treated in a primary PTCA high-volume centre using TA devices. Our study demonstrates that, in STEMI patients treated with primary PTCA, a routine strategy with TA before angioplasty guided by angiographic selection criteria is feasible in almost 50% of cases, is safe and effective, does not increase procedural time and offers good results in terms of tissue perfusion, both epicardial (TIMI flow) and myocardial (MBG, ST regression). When successfully performed, TA identifies a population with favourable in-hospital and 6-month outcome.

Thrombus Aspiration with Export Catheter in ST Elevation Myocardial Infarction

Many thrombectomy devices have failed to confirm initial promising results during primary angioplasty. This may be due to device complexity and operator experience. The objective of this study was to assess the safety and efficacy of the EXPORT catheter for thrombus aspiration in patients with ST elevation myocardial infarction (STEMI). EXPORT catheter was used in patients with STEMI and angiographic evidence of thrombus in vessels with a reference diameter > or =1.5 mm. Direct stenting and glycoprotein IIb/IIIa inhibitors were liberally employed to optimize angiographic and clinical results. Epicardial and myocardial angiographic parameters, in-hospital major adverse cardiac events (MACE, i.e., cardiac death, myocardial infarction, target vessel revascularization) were assessed. EXPORT catheter was used in 129 patients without any device-related complications. Angiographic analysis following thrombus aspiration revealed a significant improvement in TIMI frame count (P = 0.0001), myocardial perfusion (P = 0.0001), TIMI thrombus grade (P = 0.0001), and TIMI flow (P = 0.0001). Stent implantation did not significantly improve myocardial perfusion, TIMI thrombus grade, or TIMI flow, but improved TIMI frame count, minimal lumen, and reference vessel diameter. When compared to a historical STEMI control group not undergoing thrombus aspiration, our EXPORT population showed significant improvements in reperfusion parameters. In-hospital MACE were uncommon (4.5%) despite high-risk patient characteristics. Our study demonstrates that routine use of EXPORT catheter in patients with STEMI and coronary thrombosis is feasible, safe, and associated with significant improvements in flow-related angiographic parameters. The relative simplicity of this approach makes it an attractive option in this challenging situation.

Preliminary experiences using X‐sizer catheter for mechanical thrombectomy of thrombus‐containing lesions during acute coronary syndromes

Thrombus-containing lesions are frequently observed in patients with acute coronary syndromes. These lesions are prone to increased procedural risks, including distal embolization and abrupt closure of the vessel. This preliminary report evaluates if thrombus removal using a new X-Sizer catheter could reduce thrombotic burden and optimize angioplasty results. Thrombectomy was attempted with the X-Sizer catheter in 11 patients (age, 59 +/- 10 years) undergoing coronary angioplasty with angiographic evidence of intracoronary thrombus. The device uses a helix cutter contained in a 4.5 or 5.5 Fr catheter tip connected to a closed vacuum aspiration system. Procedural outcomes using detailed angiographic analysis and clinical data were obtained from all treated patients. Seven patients (64%) had acute or recent myocardial infarction and four patients (36%) presented with unstable angina. The culprit lesion was located in right coronary, left anterior, vein graft, and circumflex-marginal in five, three, two, and one patient, respectively. The mean proximal reference diameter was 3.37 +/- 0.39 mm and % diameter stenosis was 90% +/- 15% prior to thrombectomy and decreased to 72% +/- 16% afterward and was 9% +/- 10% at the end of the procedure. The TIMI flow increased from 0.8 +/- 1.0 to 2.1 +/- 0.9 following thrombectomy and the final TIMI grade was 2.9 +/- 0.3. Stents were used in 9 of 11 patients. Procedural success was achieved in 10 of 11 patients (91%). No evidence of stent thrombosis was noted among treated patients in hospital and at 30-day follow-up. In this preliminary series of patients with angiographic evidence of thrombus, the use of X-Sizer thrombectomy seems to be feasible and relatively safe, permitting thrombus removal and improved intracoronary flow.

Influence of coronary thrombus on outcome of percutaneous coronary angioplasty in the current era (the Mayo Clinic experience)

Earlier studies documented an increased risk of percutaneous coronary intervention (PCI) in patients with angiographic evidence of thrombus. With newer antiplatelet agents and stents, it is not known whether thrombus is a risk factor after PCI. This study examines whether outcome of PCI in patients with thrombus has improved, and whether thrombus is associated with adverse outcome after PCI in the current era. This single-institution retrospective analysis of PCI in 7,184 patients was divided into 2 periods: group I, 1990 to 1995 (n = 3,640), and group II, 1996 to 1999 (n = 3,544). The groups were subdivided according to the presence or absence of angiographic thrombus before PCI. We compared the outcome of PCI for patients with and without thrombus in group II. A comparison was made in the 2 groups in patients with angiographic thrombus. Procedural success improved in group II compared with group I patients with thrombus (93% vs 88%, p <0.001). There was significant reduction in abrupt closure in the recent era in patients with thrombus (4% vs 7%, p = 0.01). In group II, procedural success remained lower in patients with (93% vs 96%) than without thrombus (p <0.001). After adjusting for the significant univariate characteristics of group II patients, thrombus remained an independent predictor of Q-wave infarction (odds ratio 3.78; 95% confidence interval [CI], 1.8 to 8.0; p <0.0013) and the composite end point of death, Q-wave infarction, and emergency bypass surgery (odds ratio 2.37; 95% CI 1.4 to 4.1; p = 0.002). There was a trend toward increased in-hospital death among patients with thrombus (odds ratio 2.06; 95% CI 0.9 to 4.8; p = 0.09). The 1-year outcome after successful PCI was similar for those with and without thrombus. Despite improvement in the outcome of patients with thrombus undergoing PCI in recent years, thrombus is still an independent predictor of adverse in-hospital outcomes after PCI.

Predictors and prognosis of suboptimal coronary blood flow after primary coronary angioplasty in patients with acute myocardial infarction

We hypothesized that certain clinical and angiographic characteristics on presentation predict suboptimal infarct artery flow after percutaneous intervention during acute myocardial infarction (AMI). The goal of angioplasty (percutaneous transluminal coronary angioplasty [PTCA]) during AMI is the prompt restoration of normal flow to achieve myocardial reperfusion. However, inadequate epicardial coronary flow is observed in 10% to 20% of patients. From 2 large randomized trials—Global Use of Strategies To open Occluded arteries in Acute Coronary Syndromes-IIb, and Randomized Placebo-Controlled Trial of Platelet glycoprotein IIb/IIIa Blockade With Primary Angioplasty for Acute Myocardial Infarction—patients undergoing primary PTCA during AMI were included in the analysis. A multivariate logistic model was used to identify factors associated with final Thrombolysis In Myocardial Infarction (TIMI) flow grade ≤2. The 891 patients were aged (mean ± SD) 61 ± 12 years, 75% were men, and 39% had an anterior wall AMI. Patients underwent PTCA within 4.8 ± 3.2 hours from the onset of chest pain. The incidence of final TIMI 3 flow was 81%. TIMI flow grade ≤2 was independently associated with increasing age (odds ratio [OR] 1.39 for every 10 years, 95% confidence interval [CI] 1.19 to 1.62), increasing heart rate (OR 1.16 for every 10 beats, 95% CI 1.05 to 1.28), and presence of visible thrombus on baseline angiogram (OR 1.89, 95% CI 1.18 to 3.05). Conversely, baseline TIMI 2 or 3 flow grade (OR 0.46, 95% CI 0.28 to 0.75) and left circumflex intervention (OR 0.42, 95% CI 0.23 to 0.79) correlated with normal postprocedural coronary flow. Mortality was significantly higher in patients with TIMI ≤2 than TIMI 3 flow grade (10.2% vs 1.5%, p <0.001, respectively). Thus, angiographic evidence of thrombus and 2 pivotal clinical characteristics, advanced age and elevated heart rate, predict lack of adequate coronary reperfusion. Conversely, the presence of normal or near-normal coronary flow before intervention correlates with a good angiographic result. Mortality risk is increased in patients with postprocedural suboptimal angiographic coronary flow.

Late Thrombosis After Radiation

Five years after Condado et al1 first treated human coronary arteries with brachytherapy, there is ongoing clinical investigation into its safety and efficacy in preventing restenosis. As with any novel technique, unexpected complications may dampen early high expectations and result in pessimism and skepticism. However, time, experience, and complete data analysis will determine the reality. Costa and coworkers2 may be reacting prematurely by reporting a new phenomenon in interventional cardiology entitled “late, sudden thrombosis after PTCA plus radiotherapy.” They report 6 (6.6%) of 91 patients who presented with late total occlusion/thrombosis at angiographic follow-up; these patients were enrolled into different radiation protocols using different β-emitters at different prescribed doses. Late total occlusion or late thrombosis is a valid concern, especially when associated with acute myocardial infarction (MI). However, can we really draw any conclusion from 6 heterogeneous case reports taken from a small cohort of patients in the absence of a control group? Is this announcement based on too few data, and is it premature? An editorial based on a Brief Rapid Communication mandates the editorialist to gather additional information, disclose his own insights, and provide the readers (the jury in this case) with as much information as possible. Acute thrombosis occurs during or early after intervention, and subacute thrombosis occurs within the subsequent 30 days. Both usually present with unstable symptoms and angiographic evidence of thrombus. However, the definition of late thrombosis may be problematic. It may not present with symptoms. It may be detected only when follow-up angiography shows a late total occlusion, which could also be the result of progressive intimal hyperplasia. Late total occlusion/thrombosis should be defined as any angiographically documented total occlusion >30 days after the procedure. For patients who have a patent treatment site at 6 months and subsequently develop a total …

Holmium laser-assisted coronary angioplasty in acute ischemic syndromes.

Initial studies have shown holmium laser to be effective in ablation of coronary atheroma, and small studies that it may be helpful in ablation of thrombotic stenoses. Therefore, holmium laser-assisted coronary angioplasty was studied in 85 consecutive patients with acute ischemia syndromes. Indications for therapy were acute myocardial infarction (MI) in 7 patients (8%), post-MI ischemic in 32 patients (38%), and crescendo angina pectoris in 46 patients (54%). Coronary morphology characteristics by multivessel angioplasty prognosis group criteria were Type A in 9 (10%), Type B1 in 15 (18%), Type B2 in 44 (52%), Type C in 17 patients (20%). Angiographic evidence of thrombus was seen in 37 (44%) of patients. The laser successfully crossed the total length of the coronary narrowing in 76 patients (89%). Procedure/clinical success was 92% for the total study population, 100% for patients with acute MI, 94% for post-MI ischemia patients, and 89% for patients with crescendo angina. Lesions with and without thrombus had identical procedure success rates. Major complication rate was 3.5%, (deaths 0%, Q-wave MI 0%, and emergent bypass surgery 3.5%). Six-month angiographic restenosis rate (> 50% stenosis) was 45%. Holmium laser-assisted balloon angioplasty appears promising in the treatment of acute ischemic syndromes and thrombotic coronary lesions.

Safety and efficacy of extended urokinase infusion plus stent deployment for treatment of obstructed, older saphenous vein grafts

This study was designed to determine the safety and efficacy of extended, continuous infusion of urokinase plus stent deployment to treat older saphenous vein bypass grafts obstructed by both thrombus and atheromatous material. Thirty patients with angiographic evidence of thrombus and atheromatous material obstructing older vein grafts (mean age 8.3 years) underwent the combined interventions of urokinase infusion and stent deployment. The continuous infusion of urokinase was administered directly into each obstructed vein graft over a mean of 20.5 ± 8.1 hours (median dose 2.2 ± 0.7 million units). Stents were deployed at the sites of atheromatous obstruction either before (5 patients) or after (25 patients) infusion of urokinase. Twenty-eight of the 30 patients were successfully treated with the combined interventions (success rate 93.3%). In these 28 patients, percent diameter stenosis at the site of obstruction decreased from 86.0% to −0.2% and Thrombolysis in Myocardial Infarction trial flow increased from 1.0 to 2.5. Two patients (6.7%) developed stent thrombosis followed by myocardial infarction (1 with Q-wave infarction, 3.3%) and congestive heart failure. Minor complications included non-Q-wave myocardial infarction (5 patients, 16.7%) and access-site hemorrhage (5 patients, 16.7%). At 2-week follow-up, anginal symptoms were decreased in all 28 successfully treated patients. At 7.2 ± 3.7-month follow-up, 5 of the 28 successfully treated patients (17.9%) had reacceleration of angina and angiographically documented restenosis at the site of stent deployment. Thus, the combined interventions are highly efficacious in treating older vein grafts obstructed by both thrombus and atheromatous material, but are also associated with significant procedural complications including stent thrombosis, myocardial infarction, and access-site hemorrhage.

730-6 Histopathologic Findings in Ostial Coronary Lesions Treated with Directional Atherectomy

Conventional balloon angioplasty has had limited success in treating patients with ostial coronary stenoses. Directional coronary atherectomy (DCA) has been used in this setting with improved results. We hypothesized that this difference in device outcome is the result of differences in ostial lesion histopathology. Accordingly, we compared quantitative histopathology on tissue obtained from DCA in pts with ostial (n = 21) and non-ostial (n = 160) coronary stenoses. The % area occupied by adventitia, media, fibrocellular, sclerotic, and atheromatous tissue and new or old thrombus was calculated using computerized planimetry of appropriately stained specimens. Pts with ostial lesions were less likely to be hypertensive (29% vs 56%, p &lt; 0.05) and tended more often to be female (43% vs 26%, p = 0.09). In addition, pts with ostial lesions were less likely to have angiographic evidence of thrombus (0% vs 20%, p &lt; 0.05) or plaque ulceration (5% vs 29%, p &lt; 0.05). Reference segment diameter was similar in both groups. All pts with ostial lesions had successful DCA procedures. The histopathology (% total specimen area) is shown:Empty CellOstialNon-OstialP ValueAdventitia1.7 ± 2.80.3 ± 1.2&lt;0.001Media8.0 ± 15.62.3 ± 5.5&lt;0.01Fibrocellular50± 3334 ± 25&lt;0.01Sclerotic49 ± 3462 ± 25&lt;0.05Atheromatous15 ± 2429 ± 25&lt;0.05New thrombus8 ± 1613 ± 19NSOld thrombus11 ± 199 ± 18NS Thus, DCA of ostial lesions more commonly yields deep tissue elements compared to non-ostial lesions. In addition, ostial lesions are more cellular with a reduced content of sclerotic and atheromatous plaque. Given the high success rate of DCA in this group, it is possible that ostial plaque composition is ideally suited to DCA. These findings suggest that ostial lesions have a different histopathology which may be relevant to device selection.

The Clinical Utility of Angioscopy During Intracoronary Stent Implantation

Angiographic evidence of thrombus may have important implications during coronary stent deployment procedures. The periprocedural presence of thrombus has been shown to increase the risk of subsequent stent thrombosis. Coronary angioscopy is a new technology that may prove more accurate for the detection of coronary thrombus. Angiographic filling defects suspicious for thrombus were observed in 15 (22%) of 64 patients undergoing coronary angioscopy during stent implantation procedures. Angioscopy confirmed the presence of thrombus in 9 (60%) of these 15 patients. Protruding thrombus was found in four cases and only mural thrombus in five. In six cases (40%) thrombus was not visualized and angioscopy provided an alternative explanation for the angiographic filling defect. Bulky atherosclerotic plaque was seen protruding into the lumen in two cases, disection with protruding fronds of tissue was found in three cases and a ruptured venus valve was found in one final case. Thrombolytic therapy was administered in all four cases containing protruding thrombus, in only two of the five cases containing mural thrombus, and in none of the cases where thrombus was not visualized. Angioscopy was more accurate than angiography for the diagnosis of thrombus and allowed more precise tailoring of the intervention to the underlying anatomical substraight. This resulted in an excellent clinical outcome, with no episodes of stent thrombosis and limitation of the risks associated with thrombolytic therapy to only those patients at increased risk of a thrombotic complication.

Risk of thrombosis during coronary angioplasty with low osmolality contrast media

Studies in vitro have suggested that nonionic low osmolar contrast agents produce an increase in thrombogenicity. To determine the incidence of thrombi related to the use of nonionic low osmolar contrast media during coronary angioplasty, a double-blind randomized study was performed in 100 patients. Medication before angioplasty included oral aspirin (250 mg/day) in all cases. At the beginning of the procedure, aspirin (250 mg) and heparin (10,000 U) were intravenously administered. During the procedure patients were randomly assigned to receive either an ionic low osmolar contrast agent ioxaglate (n = 50), or a nonionic low osmolar contrast media iohexol (n = 50). The presence of thrombus was evaluated on the angiogram and on the guidewire immediately after its retrieval from the patients. Clinical, angiographic and procedural variables were similar in the 2 randomized groups. Angiographic evidence of thrombus was observed in 1 patient (2%) assigned to ioxaglate and in 11 patients (22%) assigned to iohexol (p < 0.005). One patient (2%) from the ioxaglate group and 6 patients (12%) from the iohexol group showed thrombotic residues on the guidewire (p = not significant). Three patients had acute myocardial infarction, 1 patient (2%) receiving ioxaglate and 2 patients (4%) iohexol (p = not significant). There were no deaths. Thus, compared with an ionic low osmolar contrast media ioxaglate, the nonionic low osmolar contrast agent iohexol increases the incidence of thrombus during coronary angioplasty.

Angiographic observations and clinical relevance of coronary thrombus in unstable angina pectoris

To assess the mechanisms of unstable angina, the coronary angiographic studies in 69 patients with severe unstable angina (prolonged pain or pain at rest) and in 20 patients with stable angina were blindly reviewed to assess the coronary morphologic changes in these syndromes. Coronary angiography was performed an average of 1.7 days from admission and an average of 24 hours from last symptoms of chest pain in patients with unstable angina. Angiographic studies were analyzed for evidence of coronary thrombus (intraluminal filling defects) at significant stenoses in patent vessels or thrombus at sites of total occlusion) and for coronary lesion morphology suggesting a complex or acute lesion (irregular or ill-defined margins, inhomogeneity, haziness or ulceration). Angiographic evidence of coronary thrombus was present in 40 of 69 patients (58%) with unstable angina: 31 (45%) had intraluminal filling defects and 9 (13%) had thrombotic total occlusion with well-developed collaterals present. Only 1 of 20 patients (5%) with stable angina had evidence of thrombus (p < 0.001). Complex lesions were present in 18 other unstable patients (26%) and in 2 other patients (10%) with stable angina who did not have angiographic evidence of thrombus. Overall, 58 of 69 patients (84%) with unstable angina had morphologic findings suggesting an acute process (thrombus or complex lesion) compared with 3 of 20 patients (15%) with stable angina, p < 0.0001. Thus, unstable angina is associated with a high prevalence of angiographic coronary thrombus and complex lesions suggesting an acute process, in contrast to stable angina. These findings provide additional support for the use of antithrombotic therapy in the treatment of unstable angina and provide further support for the increasing evidence suggesting a common mechanism for unstable angina and myocardial infarction.