Clopidogrel Withdrawal Research Articles

Migraine with aura after clopidogrel withdrawal: evidence of inflammation as a migraine trigger? – Case report

This article presents the case of a PFO (patent foramen ovale) closure patient with double antiplatelet therapy in whom aspirin was discontinued before clopidogrel and that, at clopidogrel withdrawal, presented “de novo” migraine with visual aura attacks. Migraines with aura associated with atrial right-to-left shunts (PFO and other atrial septal defects) are attributed to the arrival of vasoactive substances in the brain, since not cleared by the lungs. In this case, discontinuation of clopidogrel one year after PFO closure induced “de novo” migraine with aura. Conclusion Rather than confirming the prophylactic effects of clopidogrel for migraine with aura, its triggering at clopidogrel withdrawal is more likely related to a proinflammatory effect of discontinuing clopidogrel. This proinflammatory effect has been described in cardiological research, and reinforces that patients receiving dual antiplatelet therapy (clopidogrel and aspirin) should always have clopidogrel discontinued before aspirin in order to avoid proinflammatory or pro-thrombotic events.

Safety of early surgery for geriatric hip fracture patients taking clopidogrel: a retrospective case-control study of 120 patients in China.

Background:Geriatric hip fracture patients receiving clopidogrel are a surgical challenge. In China, most of these patients undergo delayed surgical treatment after clopidogrel withdrawal for at least 5 to 7 days. However, delayed surgery is associated with increased complications and mortality in the older adults. This retrospective paralleled comparison study investigated the safety of early surgery for geriatric hip fracture patients within 5 days of clopidogrel withdrawal.Methods:Acute hip fracture patients (≥65 years) who were hospitalized in the orthogeriatric co-management ward of Beijing Jishuitan Hospital between November 2016 and April 2018 were retrospectively reviewed. Sixty patients taking clopidogrel before injury and discontinued <5 days before surgery constituted the clopidogrel group. The control group constituted 60 patients not taking antiplatelet or anticoagulant drugs and matched 1:1 with the clopidogrel group for sex, fracture type, operative procedure, and time from injury to operation (±10 h). The primary outcome was perioperative blood loss and the secondary outcomes were transfusion requirement, complications, and mortality. The Student's t test or Wilcoxon signed rank sum test was used for continuous variables and the Chi-square test was used for categorical variables.Results:Age, body mass index, American Society of Anesthesiologists score, and percentage undergoing general anesthesia were comparable between the groups (P > 0.050). The percentages of patients with coronary heart disease (61.7% vs. 18.3%; P < 0.001) and cerebrovascular disease (45.0% vs. 15.0%; P < 0.010) were significantly higher in the clopidogrel vs. control groups, respectively. The median clopidogrel discontinuation time before operation was 73.0 (range: 3.0–120.0) h. There was no significant difference in the estimated perioperative blood loss between the clopidogrel group (median: 745 mL) and control group (median: 772 mL) (P = 0.866). The intra-operative transfusion rate was higher in the clopidogrel group (22/60, 36.7%) than that in the control group (12/60, 20.0%) (P < 0.050). However, there was no significant difference in the blood transfusion rate during the entire perioperative period (26/60, 43.3% vs. 20/60, 33.3%; clopidogrel group vs. control group, respectively; P > 0.050). There was no significant difference in perioperative complications, and 30-day and 1-year mortality rates between the groups.Conclusions:Early hip fracture surgery is safe for elderly patients within 5 days of clopidogrel withdrawal, without increased perioperative blood loss, transfusion requirement, complications, and mortality compared with patients not taking antiplatelet drugs.

Intravenous glycoprotein IIbIIIa inhibitor bridging for urgent coronary artery bypass graft after acute coronary syndrome

Abstract Background Previous studies have shown the safety of intravenous glycoprotein (GP) IIbIIIa inhibitors used as a bridging after ADP receptor blocker withdrawal in patients with stable coronary artery disease and previous percutaneous coronary interventions (PCI) undergoing cardiac or non-cardiac surgeries. However, there are few data analyzing GP IIbIIIa inhibitor bridging among patients with acute coronary syndromes (ACS) scheduled for coronary artery bypass graft (CABG) during the same hospitalization. Purpose To evaluate the safety of tirofiban bridging after clopidogrel withdraw in post-ACS patients schedule for CABG during the same hospitalization. Methods Fifty-six patients who underwent CABG after tirofiban bridging post-ACS (bridge group - BG) were compared to 56 sex and age-matched controls also submitted to same-hospitalization CABG post-ACS without bridging (control group - CG). All patients received aspirin plus clopidogrel for ACS; clopidogrel was withdrawn 5 to 7 days before CABG and aspirin was maintained during the whole perioperative period. The primary endpoint was chest tube output in the first 24h after CABG (CTO24h). We hypothesized that BG would be non-inferior to CG, with a non-inferiority margin of 25% in excess of CTO24h in the BG compared to the CG, based on prior literature data. Other exploratory analyses were: blood transfusions, number of red blood cells/patient and re-thoracotomy 24h after surgery. A multivariable linear regression model was developed considering CTO24h as dependent variable and adjusted for other eight co-variates, described in the figure. Results From the 112 patients included (75% men; mean age 60.2±9.3 years), in comparison with CG, BG had higher proportion of STEMI (80.0% vs. 28.6%, p&amp;lt;0.01), fibrinolytic utilization (25% vs. 7.1%, p&amp;lt;0.05), PCI in the acute phase (92.9% vs. 0%, p&amp;lt;0.01) and LMCA stenosis (30.4% vs. 7.1% p&amp;lt;0.01). Tirofiban was utilized by clinician discretion due to PCI in the same hospitalization previously to CABG (n=52), previous PCI up to 3 months before index event (n=3) or severe LMCA stenosis (n=1). BG patients received tirofiban for a mean of 4.3±2.1 days and it was withdrawn at a mean of 6.6±4.3 hours before CABG. After adjustments, BG was non-inferior to CG regarding CTO24h (figure) There were no significant differences between BG and CG regarding need for blood transfusion (26.8% vs. 26.8%, p&amp;gt;0.99), mean number of red blood cells/patient (0.3±0.8 vs 0.5±1.2, p=0.35) or re-thoracotomy due to bleeding (5.4% vs 0%, p=0.24). Conclusion Among ACS patients submitted to urgent CABG after clopidogrel withdrawal, tirofiban bridging, compared to no bridging, was not associated with higher risk of bleeding in the first 24 hours after surgery. Our study suggests that tirofiban may be a safe therapy to patients with high risk of thrombotic complication (such as stent thrombosis or re-infarction) after clopidogrel withdraw. Figure 1 Funding Acknowledgement Type of funding source: None

Economic analysis of platelet aggregability-guided surgical revascularization compared with standard of care in ACS patients: subanalysis from PLAT-CABG randomized clinical trial

Abstract Background Dual antiplatelet therapy (DAPT) is recommended for patients with acute coronary syndromes (ACS). Up to 15% are submitted to coronary artery bypass graft (CABG) during the hospitalization for the index event. However, as current guidelines recommend withdrawal of clopidogrel at least 5 days prior to CABG, this waiting time may increase hospital length of stay, thus potentially having negative impacts on costs and clinical outcomes. As previously presented at the ESC 2019 Congress, the PLAT-CABG study showed that the strategy to shortening CABG waiting time guided by platelet function test was non-inferior to the standard of care in terms of perioperative bleeding and led to shorter length of hospital stay among ACS patients. In this subanalysis, we present results regarding the in-hospital expenses for the two strategies. Purpose To determine, from the perspective of the Brazilian Government Health System (BGHS), the hospital expenses of patients undergoing CABG guided by platelet aggregability tests in comparison to the standard of care. Methods The PLAT-CABG study was a randomized and open label clinical trial testing a strategy of platelet aggregability-guided CABG after ACS versus standard-of-care. A total of 185 ACS patients on DAPT (aspirin plus clopidogrel) scheduled for on-pump or off-pump CABG were randomized to clopidogrel withdraw 5 to 7 days prior to CABG (control group) vs. daily measurements of platelet aggregability using Multiplate ADP-test (intervention group). Hospital cost (expressed in Brazilian currency - reais) subanalysis was pre-specified in the main trial statistical analysis plan. All patients had their hospital expenses covered by the BGHS and platelet aggregability tests costs were included in the analysis. Patients randomized to intervention group were allowed to undergo CABG when platelet aggregation recovered (pre-defined as Multiplate ≥46 AUC). In per protocol analysis, only patients who underwent CABG on the day after reaching the pre-specified aggregabilty cut point were analyzed. Results The main results are depicted in Figure 1. In the intention-to-treat analysis, median hospital expenses for the intervention group were R$15,202.33 and for the control group R$16,251.37 (mean difference of R$1,049.04, or 6.4%, P=0.014). In per protocol analysis, the mean hospital expenses for the intervention group were R$14,248.41 and for the control group R$ 16,039.55 (difference of R$ 1,791.14 or 11.2%, P=0.003). For an estimated 70,000 CABG procedures/year in Brazil, we estimate that the implementation of this routine would save up to R$125,370,000.00/year. Conclusion In patients with ACS taking DAPT, a strategy of platelet function-guided timing to CABG resulted in lower hospital expenses compared to a standard of care of waiting at least 5 days after clopidogrel withdrawal. Figure 1. Hospital expenses between groups Funding Acknowledgement Type of funding source: Private company. Main funding source(s): Roche Diagnostica Brazil

Thromboelastography (TEG) and Clopidogrel Withdrawal Time in Elderly Patients With Hip Fracture

Thromboelastography (TEG) and Clopidogrel Withdrawal Time in Elderly Patients With Hip Fracture

Timing of Coronary Bypass Surgery in Patients Receiving Clopidogrel: The Role of VerifyNow

We briefly report for the first time the association between a point of care platelet recovery test and the timing of coronary artery bypass grafting after clopidogrel withdrawal. We observe an association between suggested wait days and platelet recovery unit values that might potentially allow for safe shorter wait times before coronary artery bypass grafting without increased bleeding. Our results represent an observation and should prompt further validation.

Post-operative simultaneous very late two-vessel drug eluting stent thrombosis with sparing of bare metal stent in a Jehovah's witness after clopidogrel withdrawal

Very late stent thrombosis is a feared complication after drug-eluting stent (DES) implantation. Several factors related to the patient, generation and type of the deployed stent, procedure, and premature antiplatelet withdrawal are known to contribute to this complication. Herein, we describe a case of a Jehovah's witness patient who developed simultaneous two-vessel 1st generation DES thrombosis 5.4 and 3.5 years after deployment [with sparing of the bare metal stent (BMS)] in the immediate post-operative period secondary to clopidogrel withdrawal. The case was complicated by ST-segment elevation myocardial infarction, cardiogenic shock, and a ventricular fibrillation cardiac arrest requiring urgent percutaneous coronary intervention. The acute thrombosis of DESs with sparing of the BMS exemplify how they are more prone to this complication due to delayed endothelialization of stent struts and neoinitimal coverage.<Learning objective: Extreme caution should be excercised when attempting to withdraw antiplatelets immediately before surgery in patients with drug eluting stents even if the recomended 12-month period of dual antiplatelet therapy has elapsed because of the risk of very late stent thrombosis.>

Clopidogrel cessation triggers aspirin rebound in patients with coronary stent

Premature discontinuation of clopidogrel in patients undergoing percutaneous coronary intervention is a significant risk factor for thrombotic adverse outcomes. However, recent studies indicate that even discontinuation of long-term use of clopidogrel may be associated with multiple adverse outcomes, that is, rebound phenomenon whose mechanism is not definitely clear. The aim of the study was to examine the effect of clopidogrel withdrawal in those on combined aspirin and clopidogrel therapy. This prospective, multicenter study enrolled 200 patients who underwent coronary stent implantation and were on dual antiplatelet therapy (100mg aspirin+75mg clopidogrel) 1year after the stent placement. In all patients, we measured the platelet aggregation, by multiplate electrode aggregometry, using two agonists [adenosine diphosphate with PGE1 (ADPHS) and arachidonic acid (ASPI)] two times: on the day of cessation of clopidogrel and 90days after clopidogrel was stopped. Following clopidogrel discontinuation, we registered an increase in ASPI values (P<0·001), linear correlation between changes in ASPI and ADPHS values (P=0·009) and significant difference in the values of ASPI first quartile of ADPHS compared with the other three (P<0·001, P=0·016, P<0·001, I vs. II, I vs. III and I vs. IV quartile of ADPHS, respectively). Our findings show that cessation of clopidogrel causes loss of antiplatelet synergism with aspirin, leading to a weakening of the response to aspirin, which may be one explanation for the rebound after the clopidogrel cessation.

042: Real life dual antiplatelet therapy after NSTE-ACS in a Tunisian population: is there a need for 12 months of treatment?

Even if the recommended duration for dual antiplatelet therapy (DAT) after non ST elevation acute coronary syndromes (NSTE-ACS) is 12 months, evidence concerning the benefit of clopidogrel adjunction especially beyond 3 months remains poor. The aim of the study was to assess the effective clopidogrel intake and the incidence of a composite endpoint including all causes death and non fatal myocardial infarction in a Tunisian population after NSTE-ACS. We included patients admitted for NSTE-ACS in our department between January 2010 and August 2011 for whom long term evaluation was possible. In-hospital deaths were excluded (including post operative deaths). By telephone follow up, we evaluated the effective DAT duration and the occurrence of all causes death and non-fatal myocardial infarction. One hundred thirty patients were included. Mean (SD) follow up was 261 (99) days. DAT was effectively observed during 94(103 days (extremes ranging from 0 to 360 days). Angioplasty was performed in 51.5%, coronary artery bypass graft in 8.4% and medical therapy was considered in 40.1%. In 35 (26.9%) patients, aspirin was the only antiplatelet therapy taken after discharge although DAT was prescribed; 46.9% of the patients took the DAT for more than 3 months, and 23.1% for more than 6 months. The composite endpoint occurred in 6 (4.6%) patients: 2 deaths (both of cardiac causes) and 4 myocardial infarctions. Three of them were under DAT, and the 3 others remained event free during 7, 240 and 270 days after clopidogrel withdrawal. These findings suggest that DAT does not protect against death or myocardial infarction. The rebound phenomenon after clopidogrel withdrawal isn’t patent in our population. In the Tunisian context, DAT observance is poor after NSTE-ACS. Death and non fatal myocardial infarction don’t seem to be reduced by DAT and the rebound phenomenon after clopidogrel withdrawal isn’t patent. This may be in part attributed to the small sample of population and the predominantly low risk (as assessed by TIMI risk score), but larger studies are needed to strengthen the evidence for DAT after NSTE-ACS.

Five Years on Dual-Antiplatelet Therapy

Drug-eluting stents (DES) have a moderately higher incidence of stent thrombosis compared to bare metal stents (BMS) and very late DES thrombosis has been frequently described. We report a case of a 66 year-old male who experienced very late stent thrombosis at 5 years after paclitaxel-eluting stent (PES) implantation and 3 days after clopidogrel withdrawal. Intravascular ultrasound (IVUS) performed during the index procedure showed that the previously implanted PES was undersized. Since the patient could not take clopidogrel, we treated him with only a noncompliant balloon (3.0 × 15 mm) with optimal expansion as confirmed by IVUS. This case report describes a patient who continued clopidogrel treatment for 5 years and was probably protected from a procedural failure. During the current hospitalization, the patient was found to be a responder to clopidogrel after a platelet function assessment with Multiplate (Dynabyte Informationssysteme GmbH, Munich, Germany).

Clopidogrel withdrawal

Clopidogrel withdrawal

Mortality Benefit With Prasugrel in the TRITON–TIMI 38 Coronary Artery Bypass Grafting Cohort: Risk-Adjusted Retrospective Data Analysis

The objective of this study was to characterize the bleeding, transfusion, and other outcomes of patients related to the timing of prasugrel or clopidogrel withdrawal before coronary artery bypass grafting (CABG). There is little evidence to guide clinical decision making regarding the use of prasugrel in patients who may need urgent or emergency CABG. Experience with performing CABG in the presence of clopidogrel has raised concern about perioperative bleeding complications that are unresolved. A subset of the TRITON-TIMI 38 study (Trial to Assess Improvement in Therapeutic Outcomes by Optimizing Platelet Inhibition with Prasugrel-Thrombolysis In Myocardial Infarction 38), in which patients with acute coronary syndrome were randomized to treatment with aspirin and either clopidogrel or prasugrel, underwent isolated CABG (N = 346). A supplemental case report form was designed and administered, and the data combined with the existing TRITON-TIMI 38 database. Baseline imbalances were corrected for using elements of the European System for Cardiac Operative Risk Evaluation and The Society of Thoracic Surgeons predictive algorithm. A significantly higher mean 12-h chest tube blood loss (655 ± 580 ml vs. 503 ± 378 ml; p = 0.050) was observed with prasugrel compared with clopidogrel, without significant differences in red blood cell transfusion (2.1 U vs. 1.7 U; p = 0.442) or the total donor exposure (4.4 U vs. 3.0 U; p = 0.463). All-cause mortality was significantly reduced with prasugrel (2.31%) compared with 8.67% with clopidogrel (adjusted odds ratio: 0.26; p = 0.025). Despite an increase in observed bleeding, platelet transfusion, and surgical re-exploration for bleeding, prasugrel was associated with a lower rate of death after CABG compared with clopidogrel.

Perioperative management of clopidogrel therapy: the effects on in-hospital cardiac morbidity in older patients with hip fractures

Increasing numbers of older patients prescribed clopidogrel are presenting for urgent hip fracture surgery. Best practice for the management of clopidogrel therapy is unknown, although delays to surgery are associated with increased mortality. We investigated the influence of perioperative management of clopidogrel therapy on in-hospital cardiac morbidity and transfusion in this population. Retrospective review of all patients aged >60 yr, admitted to a single centre with hip fractures between June 2005 and November 2008. Acute coronary syndrome (ACS) was defined as a raised plasma troponin concentration >0.04 µg litre(-1) associated with chest pain, new ECG changes, or both. Of 1381 patients admitted with hip fractures, 114 were receiving regular clopidogrel therapy with a median age of 83.7 (60-98) yr. Clopidogrel was withheld perioperatively in 111 (98%) of these patients. Twenty-three patients (20.2%) suffered an ACS. Risk peaked for ACS [odds ratio (OR) 6.7 (95% confidence interval, CI, 1.7-25.8)] (P=0.006) between days 4 and 8 after clopidogrel withdrawal. The OR for requiring a blood transfusion during or after surgery peaked at day 1 after clopidogrel withdrawal [OR 2.31 (95% CI, 1.02-5.21)] (P=0.044). The length of withdrawal of clopidogrel therapy perioperatively was associated with a significantly increased incidence of ACS. An association between shorter withdrawal and increased blood transfusion requirements was also seen. The study emphasizes the cardiovascular risks of routinely interrupting clopidogrel therapy in this at-risk population and that a more considered, individualized, evidenced-based approach is needed.

Management of patients with recently implanted coronary stents on dual antiplatelet therapy who need to undergo major surgery.

About 5% of patients undergoing coronary stenting need to undergo surgery within the next year. The risk of perioperative cardiac ischemic events, particularly stent thrombosis (ST), is high in these patients, because surgery has a prothrombotic effect and antiplatelet therapy is often withdrawn in order to avoid bleeding. The clinical and angiographic predictors of ST are well known, and the proximity to an acute coronary syndrome adds to the risk. The current guidelines recommend delaying non-urgent surgery for at least 6 weeks after the placement of a bare metal stent and for 6-12 months after the placement of a drug-eluting stent, when the risk of ST is reduced. However, in the absence of formal evidence, these recommendations provide little support with regard to managing urgent operations. When surgery cannot be postponed, stratifying the risk of surgical bleeding and cardiac ischemic events is crucial in order to manage perioperative antiplatelet therapy in individual cases. Dual antiplatelet therapy should not be withdrawn for minor surgery or most gastrointestinal endoscopic procedures. Aspirin can be safely continued perioperatively in the case of most major surgery, and provides coronary protection. In the case of interventions at high risk for both bleeding and ischemic events, when clopidogrel withdrawal is required in order to reduce perioperative bleeding, perioperative treatment with the short-acting intravenous glycoprotein IIb-IIIa inhibitor tirofiban is safe in terms of bleeding, and provides strong antithrombotic protection. Such surgical interventions should be performed at hospitals capable of performing an immediate percutaneous coronary intervention at any time in the case of acute myocardial ischemia.

Effect of clopidogrel withdrawal on platelet reactivity and vascular inflammatory biomarkers 1 year after drug-eluting stent implantation: results of the prospective, single-centre CESSATION study

BackgroundThe optimal duration of clopidogrel treatment, particularly following drug-eluting stent (DES) implantation, remains contentious. Previous studies have observed a clustering of adverse events following clopidogrel cessation 1 year after DES,...

20 What happens to platelet function and vascular inflammation when clopidogrel is withdrawn? Insights using short thrombelastography

Introduction A clustering of adverse events, in particular stent thrombosis (ST) has been observed following clopidogrel cessation 1-year after drug-eluting stenting (DES), the aetiology of which is poorly understood. We investigated the effect of withdrawing clopidogrel in DES patients using a simple, rapid, reproducible near-patient platelet function test known as short Thrombelastography (s-TEG) that has been developed and validated by this group. Methods 33 patients on aspirin and due to stop clopidogrel at 1 year following DES were investigated. Venesection was performed at (i) 4 weeks and 24 h pre clopidogrel cessation (ii) 24 h, 48 h, 1, 2 and 4 weeks post clopidogrel cessation. At all time-points, platelet reactivity was determined using s-TEG and thromboxane (TX) B2, IL-6, CD40 ligand and high sensitivity CRP were measured. Results Clopidogrel cessation produced (i) a predictable increase in ADP-induced platelet aggregation, and (ii) an unexpected and significant rise in AA-induced platelet aggregation. TXB2 was consistently suppressed confirming inhibition of COX by aspirin. Conclusion We have described for the first time an aspirin-independent increase in AA-induced clotting following clopidogrel withdrawal in DES patients. As well as potentially helping to explain the observed clustering of ST events early after clopidogrel withdrawal, these findings raise the question as to whether AA-induced clotting is an appropriate test of aspirin sensitivity. Our results also confirm s-TEG as a plausible candidate for near-patient platelet function testing in this field.

Clopidogrel discontinuation and platelet reactivity following coronary stenting

Antiplatelet therapy with aspirin and clopidogrel is recommended for 1 year after drug-eluting stent (DES) implantation or myocardial infarction. However, the discontinuation of antiplatelet therapy has become an important issue as recent studies have suggested a clustering of ischemic events within 90 days of clopidogrel withdrawal. The objective of this investigation was to explore the hypothesis that there is a transient 'rebound' increase in platelet reactivity within 3 months of clopidogrel discontinuation. In this prospective study, platelet function was assessed in patients taking aspirin and clopidogrel for at least 1 year following DES implantation. Platelet aggregation was measured using a modification of light transmission aggregometry in response to multiple concentrations of adenosine diphosphate (ADP), epinephrine, arachidonic acid, thrombin receptor activating peptide and collagen. Clopidogrel was stopped and platelet function was reassessed 1 week, 1 month and 3 months later. Thirty-two patients on dual antiplatelet therapy were recruited. Discontinuation of clopidogrel increased platelet aggregation to all agonists, except arachidonic acid. Platelet aggregation in response to ADP (2.5, 5, 10, and 20 μm) and epinephrine (5 and 20 μm) was significantly increased at 1 month compared with 3 months following clopidogrel withdrawal. Thus, a transient period of increased platelet reactivity to both ADP and epinephrine was observed 1 month after clopidogrel discontinuation. This study demonstrates a transient increase in platelet reactivity 1 month after clopidogrel withdrawal. This phenomenon may, in part, explain the known clustering of thrombotic events observed after clopidogrel discontinuation. This observation requires confirmation in larger populations.

Clopidogrel withdrawal: Is there a “rebound” phenomenon?

Dual antiplatelet therapy with aspirin and clopidogrel is routinely indicated in patients with acute coronary syndromes and following percutaneous coronary intervention to reduce the risk of cardiovascular mortality and ischaemic events. Although clinical guidelines recommend aspirin lifelong and clopidogrel for between one and 12 months, depending upon the indication, the optimal duration of clopidogrel therapy actually remains contentious. Premature cessation of clopidogrel in patients receiving drug-eluting stents is a clear risk factor for stent thrombosis, but recent clinical studies have also demonstrated a link between "appropriate" cessation of clopidogrel and clustering of adverse clinical events. It has been suggested that this may be due to a "rebound" prothrombotic and/ or proinflammatory response associated with clopidogrel withdrawal. This review will examine the definition and concept of a "rebound" phenomenon associated with clopidogrel cessation as well as the likely mechanisms behind this effect. Within the context of clinical event clustering after clopidogrel cessation, we will also discuss (i) the clinical importance of clopidogrel and the increasing uncertainty surrounding optimal duration of therapy, (ii) the antiplatelet and anti-inflammatory properties of clopidogrel and, in particular, its influence on arachidonic acid pathways traditionally thought to be mediated predominantly by aspirin and (iii) the role of newer, more potent antiplatelet agents and potential changes to antiplatelet therapy prescribing guidelines in the future.

020 Coronary stent thrombosis of drug eluting stent in daily clinical practice: analysis of a tertiary single center registry

The large reduction in restenosis rates with drug-eluting stents (DES), compared with bare-metal stents (BMS), has already been demonstrated. In those studies this gain was not associated with safety concerns such as excess early and late stent thrombosis (ST). We tried to determine predictive factors of drug eluting instent thrombosis in a tertiary center. Our study is retrospective enrolling 619 patients who underwent drug eluting stenting. Thrombosis definition was based on the Academic Research Consortium (ACR 2008), We compared 2 groups T+ (thrombosis) et T-(no thrombosis). The rate of thrombosis was 3,7% (23 patients among 619). This complication occurred at a mean follow-up of 21,43 days. There were one case of acute thrombosis, 21 cases of subacute Thrombosis, one case of late thrombosis. No very late thrombosis was noted. Patients who had thrombosis were older (T+ = 67years old; T− = 63,16 years old), more diabetic (T+ = 65%; T− = 61,5%) but without significant difference. The occurring of stent thrombosis didn’t depend on the site nor on the technic of implantation. There was no correlation between this complication and stent sizes despite that it seems to be more frequent in the case of longer stents (T+ = 24,32; T− = 22,13; p = 0,47) and in the case of small diameter (T+ = 2,82; T− = 2,94; p = 0,36). Predictive factors of stent thrombosis were clopidogrel withdrawal for surgery (T+ = 43,47%; T− = 27,51%; p = 0,09), the early withdrawal of clopidogrel (T+ = 13,99 mois; T− = 9,08 mois; p = 0,02). Stent thrombosis was associated to the increase of major cardiovascular events (T+ = 39,13%; T = 9,7%; p < 0,001) especially myocardial infarction (T+ = 21,7%; T− = 1,67; p < 0,001), the rate of revascularisation (T+ = 13,04; T− = 3,35%; p = 0,01) but there was no significant effect on the mortality (T+ = 8,6%; T− = 3,02%; p = 0,13). Instent thrombosis is a lifethreatening complication occurring in 0 to 3,5% based on randomized studies. It is more frequent in case of drug eluting stenting.

Effect of clopidogrel premedication on clinical outcomes and bleeding complications in patients undergoing coronary artery bypass graft surgery

Objective To evaluate the effect of clopidogrel premedication on in-hospital major adverse cardiovascular and cerebral events (MACCE) and bleeding outcomes before coronary artery bypass graft surgery (CABG). Method A total of 2021 patients who underwent CABG from July 2003 to September 2005 were divided into either clopidogrel ( n = 479) or no clopidogrel (1542) group before CABG. Patients with clopidogrel administration ( n = 479) were subdivided into 7d(n = 142) group according to timing of clopidogrel withdrawal before surgery. In-hospital MACCE and perioperative bleeding outcomes were analyzed among groups. Results Patients who took clopidogrel before surgery had nonsignificantly rates of bleeding and in-hospital MACCE compared with those patients not administered clopidogrel. No differences were found about the incidence of total bleeding,minor bleeding,transfusions of red blood cells,fresh frozen plasma,whole blood and in-hosptial MACCE among three subgroups.The 7 d group [47.8% vs. 20.3%,P 7 d group ( P > 0.05). Conclusions Gopidogrel administration before CABG does not increase the incidence of in-hospital MACCE events. However,the perioperative risk of bleeding will rise if the patients withhold clopidogrel less than five days before surgery. Key words: Coronary artery bypass graft surgery; Clopidogrel; Oral antiplatelet therapy; Complication; Bleeding complications; Transfusions; Major adverse cardiovascular and cerebral events; Adverse drug reaction