Temporal trends and patterns of early clopidogrel use across the spectrum of acute coronary syndromes

Is Preoperative Clopidogrel Resistance a Predictor of Bleeding and Risks in Patients Undergoing Emergency CABG Surgery?

Objective

The aims of this study were to determine whether the detection of preoperative clopidogrel resistance in patients undergoing cardiac surgery while using clopidogrel could play a guiding role in the prediction of postoperative excessive bleeding, transfusion requirements, and risks and to provide clinically significant data.

Methods

Two hundred and twenty-two patients [median age: 59.4 (38-83) years; 38 females] undergoing emergency and elective coronary artery bypass graft (CABG) surgeries in our clinic were evaluated prospectively. Patients with multiple systemic diseases, other than diabetes mellitus (DM) and hypertension (HT), were excluded. Patients receiving clopidogrel were also evaluated for clopidogrel resistance and grouped according to the results of this test. Assessments of platelet functions were performed by multiplate impedance aggregometry method and adenosine diphosphate test.

Results

The use of postoperative fresh blood replacement and platelet transfusion was higher in patients receiving clopidogrel than in those not receiving it (P=0.001, P=0.018). DM, HT, myocardial infarction, and the number of presentation to the emergency room were significantly higher in patients receiving clopidogrel than in those not receiving it (P<0.05). No significant difference was determined between patients with and without clopidogrel resistance regarding the amount of bleeding during and after surgery, erythrocyte suspension and fresh-frozen plasma transfusion rates, preoperative troponin values, ejection fraction values, and length of hospital stays (P>0.05).

Conclusion

We think that resistance studies in patients receiving clopidogrel before cardiac surgery are not efficient to predict bleeding and bleeding-related complications in patients undergoing emergency and elective CABG surgeries.

Impact of dual antiplatelet therapy after coronary artery bypass surgery on 1-year outcomes in the Arterial Revascularization Trial

OBJECTIVES

There is still little evidence to boldport routine dual antiplatelet therapy (DAPT) with P2Y12 antagonists following coronary artery bypass grafting (CABG). The Arterial Revascularization Trial (ART) was designed to compare 10-year survival after bilateral versus single internal thoracic artery grafting. We aimed to get insights into the effect of DAPT (with clopidogrel) following CABG on 1-year outcomes by performing a post hoc ART analysis.

METHODS

Among patients enrolled in the ART (n = 3102), 609 (21%) and 2308 (79%) were discharged on DAPT or aspirin alone, respectively. The primary end-point was the incidence of major adverse cerebrovascular and cardiac events (MACCE) at 1 year including cardiac death, myocardial infarction, cerebrovascular accident and reintervention; safety end-point was bleeding requiring hospitalization. Propensity score (PS) matching was used to create comparable groups.

RESULTS

Among 609 PS-matched pairs, MACCE occurred in 34 (5.6%) and 34 (5.6%) in the DAPT and aspirin alone groups, respectively, with no significant difference between the 2 groups [hazard ratio (HR) 0.97, 95% confidence interval (CI) 0.59-1.59; P = 0.90]. Only 188 (31%) subjects completed 1 year of DAPT, and in this subgroup, MACCE rate was 5.8% (HR 1.11, 95% CI 0.53-2.30; P = 0.78). In the overall sample, bleeding rate was higher in DAPT group (2.3% vs 1.1%; P = 0.02), although this difference was no longer significant after matching (2.3% vs 1.8%; P = 0.54).

CONCLUSIONS

Based on these findings, when compared with aspirin alone, DAPT with clopidogrel prescribed at discharge was not associated with a significant reduction of adverse cardiac and cerebrovascular events at 1 year following CABG.

Single and dual antiplatelet therapy in elderly patients of medically managed myocardial infarction

Backgrounds

To examine the comparative effectiveness between dual and single antiplatelet therapies in real-world, medically managed elderly patients with acute myocardial infarction (AMI).

Methods

This retrospective study identified very elderly (> 85 years) patients, who were medically managed, with their first AMI from the Taiwan National Health Insurance claims database from 2007 to 2010. Patients were classified as dual antiplatelet therapy (DAPT) group, aspirin only group and clopidogrel only group. Study outcomes included all-cause death, cardiovascular death and gastrointestinal bleeding. Treating DAPT group as the reference, we employed a multivariable Cox regression model to compare the relative risks of outcomes between 3 groups using pairwise comparison approach.

Results

Among 1469 patients with incident ST-elevation myocardial infarction (STEMI, 14%) or non-STEMI (86%), 390 patients were prescribed DAPT, 549 aspirin only, and 530 clopidogrel only. After 9 months of follow-up, aspirin only group had similar risks of all-cause death (adjusted HR 1.21, 95% CI 0.77–1.89, p = 0.41), cardiovascular death (adjusted HR 1.16, 95% CI 0.66–2.04, p = 0.60) and gastrointestinal bleeding (adjusted HR 1.66, 95% CI 0.77–3.57, p = 0.20) in comparison with DAPT group. Clopidogrel users had a higher risk of all-cause death (adjusted HR 1.50, 95% CI 1.00–2.25, p = 0.049) but similar risks of cardiovascular death and gastrointestinal bleeding when compared with DAPT.

Conclusions

Among very elderly patients who were medically managed after AMI, single antiplatelet therapy had comparable protective effect as DAPT. But clopidogrel only strategy was associated with a higher risk of all-cause death.

Electronic supplementary material

The online version of this article (10.1186/s12877-018-0777-4) contains supplementary material, which is available to authorized users.

Management and Prevention of Saphenous Vein Graft Failure: A Review

Coronary artery bypass grafting (CABG) remains a vital treatment for patients with multivessel coronary artery disease (CAD), especially diabetics. The long-term benefit of the internal thoracic artery graft is well established and remains the gold standard for revascularization of severe CAD. It is not always possible to achieve complete revascularization through arterial grafts, necessitating the use of saphenous vein grafts (SVG). Unfortunately, SVGs do not have the same longevity, and their failure is associated with significant adverse cardiac outcomes and mortality. This paper reviews the pathogenesis of SVG failure, highlighting the difference between early, intermediate, and late failure. It also addresses the different surgical techniques that affect the incidence of SVG failure, as well as the medical and percutaneous prevention and treatment options in contemporary practice.

Optimal Antiplatelet Therapy in ST-Segment Elevation Myocardial Infarction

Cardiovascular disease is the leading cause of death worldwide. Case-fatality rates for myocardial infarction (MI) in the United States have decreased over the past decades, in large part due to advances in the treatment of acute MI and secondary preventive therapy after MI. Antiplatelet therapy remains the cornerstone of treatment of MI. This article reviews the current state of antiplatelet therapy in ST-segment elevation MI.

Contemporary Trends in Oral Antiplatelet Agent Use in Patients Treated with Percutaneous Coronary Intervention for Acute Coronary Syndrome

BACKGROUND

Recent trials demonstrated the efficacy of prasugrel and ticagrelor compared with clopidogrel in the reduction of cardiovascular complications in patients with acute coronary syndrome (ACS). However, it is unclear how use of the 3 antiplatelet medications has changed in commercially insured patients since the advent of the new agents.

OBJECTIVES

To (a) describe the adoption of prasugrel and ticagrelor in patients who received percutaneous coronary intervention (PCI) for the onset of ACS and (b) explore patient factors associated with the selection of the drug to provide insight into utilization patterns of these antiplatelet agents.

METHODS

Patients who received a new dispensing of an antiplatelet agent following a hospitalization for a PCI administered for ACS were identified from insurance claims between 2009 and 2013. Demographics and comorbid conditions were determined based on a 6-month period before the ACS event. Longitudinal trends in antiplatelet agent selection were illustrated using descriptive statistics segmented by month and quarter. Using logistic regressions with stepwise model selection, factors associated with use of the newer medications, as well as with the selection between ticagrelor and prasugrel, were identified.

RESULTS

The analysis included 66,335 subjects. The use of clopidogrel decreased from 100% to roughly 65% of total antiplatelet agent use by the end of 2011 and leveled off thereafter. The introduction of ticagrelor in 2011 coincided with a drop in prasugrel initiation from 35%-18% by December 2013. The use of new agents as opposed to use of clopidogrel was associated with younger age (< 65 years), male gender, and a diagnosis of ST-elevation myocardial infarction. In addition, conditions increasing mortality and risk of cardiovascular complication were associated with higher odds of using clopidogrel. The odds of using ticagrelor over prasugrel increased with older age and history of a cerebrovascular event.

CONCLUSIONS

In 2013, clopidogrel remained the most prescribed agent. Meanwhile, ticagrelor had gradually replaced a substantial portion of prasugrel initiation. Further investigation into outcomes associated with the newer agents, as well as reasons behind the conservative use of the antiplatelet agents, is warranted.

DISCLOSURES

No funding was received for the conduct of this study. DiDomenico received an honorarium from Amgen for the preparation of a heart failure drug monograph for Pharmacy Practice News and was a co-investigator on funded research for the Patient-Centered Outcomes Research Institute. DiDomenico also serves as an advisory board member for a heart failure program at Otsuka America Pharmaceuticals and as an advisory board member at Novartis Pharmaceuticals. Touchette has received unrestricted grant funding from Cardinal Health and Sunovion Pharmaceuticals and has also served as a consultant to and director of the American College of Clinical Pharmacy Practice-Based Research Network on a study funded by Pfizer. None of the authors of this study are involved in financial or personal relationships with agencies, institutions, or organizations that inappropriately influenced the statistical analysis plan or interpretation of the results. Study concept and design were contributed by Kim, Lee, Touchette, and Walton, with assistance from DiDomenico and Ardati. Kim and Lee collected the data, and data interpretation was performed by Lee, DiDomenico, and Ardati, along with Kim and Walton and assisted by Touchette. The manuscript was written by Kim and Walton, with assistance from the other authors, and revised by Kim, Walton, and Lee, with assistance from the other authors.

The underutilisation of dual antiplatelet therapy in acute coronary syndrome

BACKGROUND

Despite guideline recommendation of dual antiplatelet therapy (DAPT) in treating ACS, DAPT is underutilized. Our objective was to determine independent predictors of DAPT non-prescription in ACS and describe pattern of DAPT prescription over time.

METHODS

Patients presenting to 41 Australian hospitals with an ACS diagnosis between 2009 and 2016 were stratified according to discharge prescription with DAPT and single antiplatelet therapy (SAPT) or no antiplatelet therapy. Multiple stepwise logistic regression, accounting for within hospital clustering, was used to determine the independent predictors of DAPT non-prescription, defined as discharge with SAPT alone or no antiplatelet agent.

RESULTS

8939 patients survived to discharge with an ACS diagnosis. Of these, 6294 (70.4%) patients were discharged on DAPT, 2154 (24.1%) on SAPT and 491 (5.5%) on no antiplatelet agent. Independent predictors of DAPT non-prescription in the overall cohort were: in-hospital CABG (OR 0.09, 95%CI 0.05-0.14), discharge with warfarin (0.10 (0.07-0.14)), in hospital major bleeding (0.48 (0.34-0.67), diagnosis of unstable angina (0.35, (0.27-0.45)), non-ST-elevation myocardial infarction (0.67 (0.57-0.78)) [both vs. ST-segment elevation myocardial infarction], in hospital atrial arrhythmia (0.72 (0.60-0.86)), history of hypertension (0.83 (0.73-0.94)) and GRACE high risk (0.83 (0.71-0.98)). There was an increase in prescription of DAPT and a shift towards ticagrelor over clopidogrel for ACS from 2013 to 2016 (p<0.0001), but no overall change in the frequency of DAPT prescription over the entire study period.

CONCLUSION

This study revealed high-risk ACS subgroups who do not receive optimal DAPT. Strategies are necessary to bridge the treatment gap in ACS antiplatelet management.

Adherence to Cardiac Practice Guidelines in the Management of Non-ST-Elevation Acute Coronary Syndromes: A Systematic Literature Review

BACKGROUND

In the management of non-ST-elevation acute coronary syndrome (NSTACS) a gap between guideline-recommended care and actual practice has been reported. A systematic overview of the actual extent of this gap, its potential impact on patient-outcomes, and influential factors is lacking.

OBJECTIVE

To examine the extent of guideline adherence, to study associations with the occurrence of adverse cardiac events, and to identify factors associated with guideline adherence.

METHOD

Systematic literature review, for which PUBMED, EMBASE, CINAHL, and the Cochrane library were searched until March 2016. Further, a manual search was performed using reference lists of included studies. Two reviewers independently performed quality-assessment and data extraction of the eligible studies.

RESULTS

Adherence rates varied widely within and between 45 eligible studies, ranging from less than 5.0 % to more than 95.0 % for recommendations on acute and discharge pharmacological treatment, 34.3 % - 93.0 % for risk stratification, and 16.0 % - 95.8 % for performing coronary angiography. Seven studies indicated that higher adherence rates were associated with lower mortality. Several patient-related (e.g. age, gender, co-morbidities) and organization-related (e.g. teaching hospital) factors influencing adherence were identified.

CONCLUSION

This review showed wide variation in guideline adherence, with a substantial proportion of NST-ACS patients possibly not receiving guideline-recommended care. Consequently, lower adherence might be associated with a higher risk for poor prognosis. Future research should further investigate the complex nature of guideline adherence in NST-ACS, its impact on clinical care, and factors influencing adherence. This knowledge is essential to optimize clinical management of NSTACS patients and could guide future quality improvement initiatives.

Baseline characteristics, adenosine diphosphate receptor inhibitor treatment patterns, and in-hospital outcomes of myocardial infarction patients undergoing percutaneous coronary intervention in the prospective Canadian Observational AntiPlatelet sTudy (COAPT)

BACKGROUND

Contemporary use of dual antiplatelet therapy and consistency with guideline recommendations in acute coronary syndrome patients undergoing percutaneous coronary intervention (PCI) have not been well characterized.

METHODS

The COAPT was a prospective, observational, multicenter, longitudinal study of patients with myocardial infarction (MI) undergoing PCI. Baseline characteristics, treatment patterns, processes of care, factors associated with switching to and from novel adenosine diphosphate receptor inhibitors (ADPris), and in-hospital outcomes are described.

RESULTS

Among 2,179 MI patients undergoing PCI during their index hospitalization, 1,328 (60.9%) had ST elevation. Initial ADPri use included clopidogrel in 1,812 (83.2%), prasugrel in 125 (5.7%), and ticagrelor in 242 (11.1%). At discharge, 1,597 patients (73.4%) were prescribed clopidogrel, 220 (10.1%) prasugrel, and 358 (16.5%) ticagrelor. Switching between ADPri therapies during the index hospitalization occurred in 15.3%, 22.4%, and 25.2% of patients initially started on clopidogrel, prasugrel, and ticagrelor, respectively. Most switches over the 15-month study period occurred during the index admission (16.8% of patients vs 4.4% switches postdischarge). Major adverse cardiovascular events occurred in 7.5% of patients during the index hospitalization. In-hospital bleeding events occurred in 6.0% of patients and most were mild.

CONCLUSIONS

Despite randomized trial evidence and guideline recommendations, only a minority of Canadian MI patients undergoing PCI initially received or were discharged on one of the newer ADPri agents. These findings suggest an opportunity to improve upon the appropriate selection of the ADPris at index hospitalization and discharge in Canadian MI patients undergoing PCI.

Secondary Prevention Beyond Hospital Discharge for Acute Coronary Syndrome: Evidence-Based Recommendations

In the past 3 decades, a better understanding of the pathophysiology of cardiovascular disease has resulted in innovations in the treatment and prevention of its clinical manifestations such as death, myocardial infarction, or stroke. After an acute coronary syndrome there are short- and long-term risks of subsequent cardiovascular events. This leads to opportunities to initiate strategies to reduce complications resulting from myocardial injury (cardiac protection) and to prevent recurrent acute coronary events (vascular protection). The results from clinical trials inform best practice and guidelines for patient management. Despite clear and consistent guidelines, an important number of patients are not receiving these treatments. Moreover, many others do not receive treatment that follows the strategy proven in the clinical trial and this is associated with a significant loss of opportunities to improve outcomes. The Canadian Heart Research Centre has therefore assembled a panel of experts to provide a review of available data and distill it to specific evidence-based recommendations that can be used by specialists and primary care physicians as a platform for secondary prevention. The therapeutic recommendations are conveniently divided into vascular protection (dual antiplatelet therapy, lipid-lowering, and renin angiotensin system inhibition) which should be considered in all patients; cardiac protection (addition of β-blocker therapy) in patients with left ventricular dysfunction including consideration for management of heart failure; and continuing management of risk factors and comorbid conditions on the basis of the specific patient profile. These recommendations are intended as a decision support tool and a quick reference for Canadian physicians.

When is the Best Time for the Second Antiplatelet Agent in Non-St Elevation Acute Coronary Syndrome?

Dual antiplatelet therapy is a well-established treatment in patients with non-ST elevation acute coronary syndrome (NSTE-ACS), with class I of recommendation (level of evidence A) in current national and international guidelines. Nonetheless, these guidelines are not precise or consensual regarding the best time to start the second antiplatelet agent. The evidences are conflicting, and after more than a decade using clopidogrel in this scenario, benefits from the routine pretreatment, i.e. without knowing the coronary anatomy, with dual antiplatelet therapy remain uncertain. The recommendation for the upfront treatment with clopidogrel in NSTE-ACS is based on the reduction of non-fatal events in studies that used the conservative strategy with eventual invasive stratification, after many days of the acute event. This approach is different from the current management of these patients, considering the established benefits from the early invasive strategy, especially in moderate to high-risk patients. The only randomized study to date that specifically tested the pretreatment in NSTE-ACS in the context of early invasive strategy, used prasugrel, and it did not show any benefit in reducing ischemic events with pretreatment. On the contrary, its administration increased the risk of bleeding events. This study has brought the pretreatment again into discussion, and led to changes in recent guidelines of the American and European cardiology societies. In this paper, the authors review the main evidence of the pretreatment with dual antiplatelet therapy in NSTE-ACS.

Current status of data on cangrelor

P2Y12 receptor inhibition in addition to aspirin is the cornerstone of treatment in patients with acute coronary syndromes (ACS) and those undergoing percutaneous coronary intervention (PCI). Despite advances in contemporary antithrombotic therapy, periprocedural thrombotic complications such as myocardial infarction and stent thrombosis remain a major concern in patients treated with PCI. Current practice guidelines recommend treatment with a P2Y12 receptor inhibitor as early as possible in patients with ACS. Existing oral P2Y12 receptors inhibitors (clopidogrel, prasugrel, or ticagrelor) have several limitations such as delayed onset and offset of action, interindividual variation, and only oral availability. Cangrelor, an intravenous, fast-onset, direct-acting P2Y12 receptor inhibitor offers potent platelet inhibition that is rapidly reversible. In large randomized trials, cangrelor has shown substantial reduction in ischemic events with no increase in severe bleeding compared with clopidogrel among patients undergoing PCI. Cangrelor is approved as an adjunct to PCI to reduce the risk of periprocedural MI, repeat coronary revascularization, and stent thrombosis in patients who have not been pretreated with a P2Y12 receptor inhibitor and are not receiving a glycoprotein IIb/IIIa inhibitor. This review aims at providing a comprehensive analysis of the current evidence pertaining to the role of cangrelor in contemporary practice.

Should dual antiplatelet therapy be used in patients following coronary artery bypass surgery? A meta-analysis of randomized controlled trials

BACKGROUND

We assessed the effectiveness of dual antiplatelet therapy (DAPT) post elective or urgent (i.e., post acute coronary syndrome [ACS]) coronary artery bypass graft surgery (CABG).

METHODS

We systematically searched MEDLINE, EMBASE, and the Cochrane Registry from inception to August 2015. Randomized controlled trials (RCTs) in adults undergoing CABG comparing either dual vs. single antiplatelet therapy or higher- vs. lower-intensity DAPT were identified.

RESULTS

Nine RCTs (n = 4,887) with up to 1y follow-up were included. Five RCTs enrolled patients post-elective CABG (n = 986). Two multi-centre RCTs enrolled ACS patients who subsequently underwent CABG (n = 2,155). These 7 RCTs compared clopidogrel plus aspirin to aspirin alone. Two other multi-centre RCTs reported on ACS patients who subsequently underwent CABG comparing higher intensity DAPT with either ticagrelor (n = 1,261) or prasugrel (n = 485) plus aspirin to clopidogrel plus aspirin. Post-operative anti-platelet therapy was started when chest tube bleeding was no longer significant, typically within 24-48 h. There were no differences in all-cause mortality in clopidogrel plus aspirin vs. aspirin RCTs; conversely, all-cause mortality was significantly lower in ticagrelor and prasugrel vs. clopidogrel RCTs (risk ratio[RR] 0.49, 95% confidence interval[CI] 0.33-0.71, p = 0.0002; 2 RCTs, n = 1695; I(2)  = 0%; interaction p < 0.01 compared to clopidogrel plus aspirin vs aspirin RCTs). There were no differences in myocardial infarctions, strokes, or composite outcomes. Overall, major bleeding was not significantly increased (RR 1.31, 95% CI 0.81-2.10, p = 0.27; 7 RCTs, n = 4500). There was heterogeneity (I(2)   = 42%) due almost entirely to higher bleeding reported for the prasugrel RCT which included mainly CABG-related major bleeding (RR 3.15, 95% CI 1.45-6.87, p = 0.004; 1 RCT, n = 437).

CONCLUSIONS

Most RCT data for DAPT post CABG is derived from subgroups of ACS patients in DAPT RCTs requiring CABG who resume DAPT post-operatively. Limited RCT data with heterogeneous trial designs suggest that higher intensity (prasugrel or ticagrelor) but not lower intensity (clopidogrel) DAPT is associated with an approximate 50% lower mortality in ACS patients who underwent CABG based on post-randomization subsets from single RCTs. Large prospective RCTs evaluating the use of DAPT post-CABG are warranted to provide more definitive guidance for clinicians.

Early clopidogrel versus prasugrel use among contemporary STEMI and NSTEMI patients in the US: insights from the National Cardiovascular Data Registry

Background

P2Y12 antagonist therapy improves outcomes in acute myocardial infarction (MI) patients. Novel agents in this class are now available in the US. We studied the introduction of prasugrel into contemporary MI practice to understand the appropriateness of its use and assess for changes in antiplatelet management practices.

Methods and Results

Using ACTION Registry‐GWTG (Get‐with‐the‐Guidelines), we evaluated patterns of P2Y12 antagonist use within 24 hours of admission in 100 228 ST elevation myocardial infarction (STEMI) and 158 492 Non‐ST elevation myocardial infarction (NSTEMI) patients at 548 hospitals between October 2009 and September 2012. Rates of early P2Y12 antagonist use were approximately 90% among STEMI and 57% among NSTEMI patients. From 2009 to 2012, prasugrel use increased significantly from 3% to 18% (5% to 30% in STEMI; 2% to 10% in NSTEMI; P for trend <0.001 for all). During the same period, we observed a decrease in use of early but not discharge P2Y12 antagonist among NSTEMI patients. Although contraindicated, 3.0% of patients with prior stroke received prasugrel. Prasugrel was used in 1.9% of patients ≥75 years and 4.5% of patients with weight <60 kg. In both STEMI and NSTEMI, prasugrel was most frequently used in patients at the lowest predicted risk for bleeding and mortality. Despite lack of supporting evidence, prasugrel was initiated before cardiac catheterization in 18% of NSTEMI patients.

Conclusions

With prasugrel as an antiplatelet treatment option, contemporary practice shows low uptake of prasugrel and delays in P2Y12 antagonist initiation among NSTEMI patients. We also note concerning evidence of inappropriate use of prasugrel, and inadequate targeting of this more potent therapy to maximize the benefit/risk ratio.

Use of clopidogrel post-coronary artery bypass surgery in canadian patients with acute coronary syndromes

BACKGROUND

Randomized trials have established the efficacy of clopidogrel in acute coronary syndromes (ACS). The benefit of clopidogrel has also been observed in the subgroup of ACS patients who subsequently undergo coronary artery bypass surgery (CABG); however, this therapy is discontinued preoperatively and the frequency with which clopidogrel is restarted post-CABG is unknown.

METHODS

We examined the pattern of clopidogrel use in the Canadian Global Registry of Acute Coronary Events (GRACE), GRACE2, and CANRACE (2003-2008) post-CABG ACS patients. We stratified the patients according to whether they underwent CABG during their index hospitalization for ACS and whether they were prescribed clopidogrel at discharge.

RESULTS

Among those patients in whom clopidogrel status at discharge was known, 5904 (60%) of 9841 were discharged from hospital on clopidogrel. Use of clopidogrel at discharge was observed in 2222 (40.8%) of 5443 patients who were medically managed (ie, did not undergo percutaneous coronary intervention [PCI] or CABG) and in 3585 (90.1%) of 3980 patients who underwent in-hospital PCI. Overall, 455 (3.3%) of 13,776 patients underwent CABG during the index hospitalization; 255 (56%) patients were started on clopidogrel during the first 24 hours, and 66 of these patients (25.9%) were discharged on clopidogrel. In contrast, 5681 (61.3%) of the 9262 patients who did not undergo in-hospital CABG were discharged on clopidogrel.

CONCLUSIONS

Although current guidelines recommend the use of clopidogrel post-CABG in patients with ACS, our observations suggest that only 1 in 4 or 5 Canadian patients are discharged on this therapy.

Dual antiplatelet therapy in patients requiring urgent coronary artery bypass grafting surgery: a position statement of the Canadian Cardiovascular Society

Acute coronary syndrome (ACS) guidelines recommend that most patients receive dual antiplatelet therapy with clopidogrel and acetylsalicylic acid (ASA) at the time of presentation to prevent recurrent ischemic events. Approximately 10% of ACS patients require coronary artery bypass grafting surgery (CABG) during the index admission. Most studies show that patients who receive ASA and clopidogrel within five days of CABG have an increase in operative bleeding. Current consensus guidelines recommend discontinuation of clopidogrel therapy at least five days before planned CABG to reduce bleeding-related events. However, high-risk individuals may require urgent surgery without delay, to reduce the risk of potentially fatal ischemic events. The present multidisciplinary position statement provides evidence- based recommendations for the optimal use of dual antiplatelet therapy to balance ischemic and bleeding risks in patients with recent ACS who may require urgent CABG.

RECOMMENDATIONS

1. All ACS patients should be considered for dual antiplatelet therapy with ASA and clopidogrel at the earliest opportunity, despite the possibility of a need for urgent CABG. 2. For patients who have received clopidogrel and ASA, and require CABG: * Those at high risk of an early fatal event (eg, with refractory ischemia despite optimal medical treatment, and with high-risk coronary anatomy (eg, severe left main stenosis with severe right coronary artery disease), should be considered for early surgery without discontinuation of clopidogrel. * In patients with a high bleeding risk (eg, previous surgery, complex surgery) who are also at high risk for an ischemic event, consideration should be given to discontinuing clopidogrel for three to five days before surgery. * Patients at a lower risk for ischemic events (most patients) should have clopidogrel discontinued five days before surgery. 3. For patients who have CABG within five days of receiving clopidogrel and ASA, the risk of major bleeding and transfusion can be minimized by applying multiple strategies before and during surgery. 4. Patients who receive clopidogrel pre-CABG for a recent ACS indication should have clopidogrel restarted after surgery to decrease the risk of recurrent ACS. 5. For patients with a recent coronary stent, the decision to continue clopidogrel until the time of surgery or to discontinue will depend on the risk and potential impact of stent thrombosis. Restarting clopidogrel after CABG will depend on whether the stented vessel was revascularized, the type of stent and the time from stent implantation. Clopidogrel should be restarted when hemostasis is assured to prevent recurrent acute ischemic events.

Underutilization of clopidogrel and glycoprotein IIb/IIIa inhibitors in non-ST-elevation acute coronary syndrome patients: the Canadian global registry of acute coronary events (GRACE) experience

BACKGROUND

There are limited contemporary data on the early use of clopidogrel or glycoprotein (Gp) IIb/IIIa inhibitors, alone versus combination therapies, in non-ST-elevation acute coronary syndrome (NSTE-ACS).

METHODS

This study included 5,806 Canadian NSTE-ACS patients with elevated cardiac biomarker and/or ST deviation on presentation in the prospective GRACE between 2003-2007. We stratified the study population according to the management strategy (non-invasive vs invasive) and into low-(GRACE risk score <or=108), intermediate- (109-140), and high-risk groups (>or=141).

RESULTS

Overall, 3,893 patients (67.1%) received early (<or=24 hours of admission) antiplatelet therapy; the rates of use were 76%, 73%, and 57% in the low-, intermediate-, and high-risk groups, respectively (P for trend < .001). Only 54% of the conservatively managed patients and 12% of the invasively managed patients received early clopidogrel and GpIIb/IIIa inhibitors, respectively. High-risk patients were less likely (adjusted odds ratio = 0.48, 95% CI 0.39-0.59, P < .001) to receive early clopidogrel or GpIIb/IIIa inhibitors, whereas in-hospital catheterization was an independent positive predictor (adjusted odds ratio = 2.02, 95% CI 1.74-2.34, P < .001) of use.

CONCLUSIONS

In this contemporary NSTE-ACS population, both clopidogrel and GpIIb/IIIa inhibitors were targeted toward patients treated with an invasive strategy but paradoxically toward the lower-risk group. In particular, clopidogrel appeared to be underused among conservatively managed patients despite its proven efficacy, whereas GpIIb/IIIa inhibitors were administered to only a minority of the high-risk patients with elevated cardiac biomarkers. Our findings emphasize the ongoing need to promote the optimal use of evidence-based antiplatelet therapies among high-risk patients with NSTE-ACS.