Impact of bleeding severity on clinical outcomes among patients with acute coronary syndromes

Relationship between baseline haemoglobin and major bleeding complications in acute coronary syndromes

AIMS

In patients with acute coronary syndromes (ACS), the negative impact of baseline haemoglobin levels on ischaemic events, particularly death, is well established, but the association with bleeding risk is less well studied. The aim of this study was to assess the impact of baseline haemoglobin levels on major bleeding complications.

METHODS AND RESULTS

Pooled analysis of OASIS 5 and 6 data involving 32 170 patients with ACS with and without ST-segment elevation was performed. The association between baseline haemoglobin and major bleeding or ischaemic events was examined using multiple regression model.

MAIN OUTCOME MEASURES

were 30-day rates of major bleeding, death, and death/myocardial infarction (MI) analysed according to baseline haemoglobin levels. Baseline haemoglobin level independently predicted the risk of overall, procedure-related, and non-procedure-related major bleedings at 30 days [odds ratio (OR) 0.94, 95% CI 0.90-0.98; OR 0.94, 95% CI 0.90-0.99; and OR 0.89, 95% CI 0.83-0.95, respectively, per 1 g/dL haemoglobin increment above 10 g/dL]. In addition, a curvilinear relationship between baseline haemoglobin levels and death at 30 days was observed with a 6% decrease in the risk for every 1 g/dL haemoglobin increment above 10 g/dL up to 15.9 g/dL (OR 0.94, 95% CI 0.90-0.98) and a 19% increase above this value (OR 1.19, 95% CI, 0.98-1.43). A similar relationship for the composite outcome of death/MI was observed.

CONCLUSION

A low baseline haemoglobin level is an independent predictor of the risk of major bleeding in ACS as well as of the risk of death and death and MI. Among other predictors of bleeding risk, baseline haemoglobin should be taken into account in patients presenting with ACS.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov number, NCT00139815. http://clinicaltrials.gov/ct2/show/NCT00139815?term=NCT00139815&rank=1.

Predictive value of post-treatment platelet reactivity for occurrence of post-discharge bleeding after non-ST elevation acute coronary syndrome. Shifting from antiplatelet resistance to bleeding risk assessment?

AIMS

We assessed prospectively the association between occurrence of post-discharge non-CABG-related TIMI major and minor bleeding and post-treatment platelet reactivity in patients with non-ST elevation acute coronary syndrome (NSTE ACS).

METHODS AND RESULTS

Five hundred and ninety-seven consecutive patients admitted with NSTE ACS were prospectively included. Between hospital discharge and one month follow-up, we observed 16 (2.7%) non-CABG-related TIMI haemorrhagic complications including five (0.84%) major and 11 (1.8%) minor bleeds. Patients with bleeding had significantly lower post-treatment values of ADP-induced aggregation (43+/-14% versus. 56+/-19%, p=0.002) and platelet reactivity index VASP (43+/-14% versus 54+/-23%; p=0.04) and a trend for lower values of arachidonic acid-induced aggregation (2.4+/-5.4 versus 13+/-21; p=0.27). After stratification by quartiles based on post-treatment ADP-induced platelet aggregation, we identified patients in the first quartile as hyper-responders with very low post-treatment platelet reactivity, below <40%. The risk of TIMI major and minor bleeding was significantly higher in the first quartile of hyper-responders than in the others quartiles: 10 (6.6%) versus six (1.4%), p=0.001.

CONCLUSIONS

Our results suggest that assessment of post-treatment platelet reactivity might be used to detect hyper-responders to antiplatelet therapy with higher risk of non-CABG related bleeding and tailor antiplatelet therapy according to both ischaemic and bleeding risk.

Bleeding increases the risk of ischemic events in patients with peripheral arterial disease

BACKGROUND

Patients with peripheral arterial disease are at high risk of ischemic events and therefore are treated with antithrombotics. In patients with coronary artery disease or cerebrovascular disease, bleeding is related to the subsequent occurrence of ischemic events. Our objective was to assess whether this is also the case in patients with peripheral arterial disease.

METHODS AND RESULTS

All patients from the Dutch Bypass and Oral Anticoagulants or Aspirin (BOA) Study, a multicenter randomized trial comparing oral anticoagulants with aspirin after infrainguinal bypass surgery, were included. The primary outcome event was the composite of nonfatal myocardial infarction, nonfatal ischemic stroke, major amputation, and cardiovascular death. To identify major bleeding as an independent predictor for ischemic events, crude and adjusted hazard ratios with 95% confidence intervals were calculated with multivariable Cox regression models. From 1995 until 1998, 2650 patients were included with 101 nonfatal major bleedings. During a mean follow-up of 14 months, the primary outcome event occurred in 218 patients; 22 events were preceded by a major bleeding. The mean time between major bleeding and the primary outcome event was 4 months. Major bleeding was associated with a 3-fold increased risk of subsequent ischemic events (crude hazard ratio, 3.0; 95% confidence interval, 1.9 to 4.6; adjusted hazard ratio, 3.0; 95% confidence interval, 1.9 to 4.7).

CONCLUSIONS

In patients with peripheral arterial disease, as in patients with coronary artery disease or cerebrovascular disease, major bleeding was independently associated with major ischemic complications. Without compromising the benefits of antithrombotics, these findings call for caution relative to the risks of major bleeding.

Transradial intervention for minimizing bleeding complications in percutaneous coronary intervention

Femoral arterial access site complications are responsible for a substantial proportion of the bleeding complications that occur in patients undergoing percutaneous coronary intervention (PCI). Because bleeding is associated with an increase in morbidity and mortality, pharmacologic and nonpharmacologic strategies associated with lower bleeding risk may improve outcomes. From this perspective, radial artery access, which is associated with a similar rate of success as femoral artery access with lower rates of bleeding, might become the "gold standard" for PCI. Although transradial technique requires a specific skill set and significant learning curve, success rates comparable to those of the femoral approach may be achieved. The benefits of radial access may be further enhanced by using antithrombotic strategies that maintain efficacy but limit bleeding risk. Indeed, a substantial proportion of bleeding complications unrelated to the access site occur, a finding that supports the use of safer antithrombotic regimens to optimize patient outcomes.

The Thrombin Receptor Antagonist for Clinical Event Reduction in Acute Coronary Syndrome (TRA*CER) trial: study design and rationale

BACKGROUND

The protease-activated receptor 1 (PAR-1), the main platelet receptor for thrombin, represents a novel target for treatment of arterial thrombosis, and SCH 530348 is an orally active, selective, competitive PAR-1 antagonist. We designed TRA*CER to evaluate the efficacy and safety of SCH 530348 compared with placebo in addition to standard of care in patients with non-ST-segment elevation (NSTE) acute coronary syndromes (ACS) and high-risk features.

TRIAL DESIGN

TRA*CER is a prospective, randomized, double-blind, multicenter, phase III trial with an original estimated sample size of 10,000 subjects. Our primary objective is to demonstrate that SCH 530348 in addition to standard of care will reduce the incidence of the composite of cardiovascular death, myocardial infarction (MI), stroke, recurrent ischemia with rehospitalization, and urgent coronary revascularization compared with standard of care alone. Our key secondary objective is to determine whether SCH 530348 will reduce the composite of cardiovascular death, MI, or stroke compared with standard of care alone. Secondary objectives related to safety are the composite of moderate and severe GUSTO bleeding and clinically significant TIMI bleeding. The trial will continue until a predetermined minimum number of centrally adjudicated primary and key secondary end point events have occurred and all subjects have participated in the study for at least 1 year. The TRA*CER trial is part of the large phase III SCH 530348 development program that includes a concomitant evaluation in secondary prevention.

CONCLUSION

TRA*CER will define efficacy and safety of the novel platelet PAR-1 inhibitor SCH 530348 in the treatment of high-risk patients with NSTE ACS in the setting of current treatment strategies.

Prevalence, predictors, and in-hospital outcomes of non-infarct artery intervention during primary percutaneous coronary intervention for ST-segment elevation myocardial infarction (from the National Cardiovascular Data Registry)

Guidelines support percutaneous coronary intervention (PCI) of the noninfarct-related artery during primary PCI for ST-segment elevation myocardial infarction (STEMI) in patients with hemodynamic compromise; however, in patients without hemodynamic compromise, PCI of the noninfarct-related artery is given a class III recommendation. We analyzed the National Cardiovascular Data Registry (n = 708,481 admissions, 638 sites) to determine the prevalence, predictors, and in-hospital outcomes of primary multivessel PCI from 2004 to 2007. Patients with STEMI and multivessel coronary artery disease who were undergoing primary PCI were identified (n = 31,681). After excluding the patients treated with staged PCI (n = 2,745), 10.8% (n = 3,134) of the remaining population (n = 28,936) were treated with multivessel PCI. Patients undergoing multivessel PCI were at higher risk and were more likely to be in cardiogenic shock. The overall in-hospital mortality rates were greater in patients undergoing multivessel PCI (7.9% vs 5.1%, p <0.01). Among patients with STEMI and cardiogenic shock (n = 3,087), those receiving multivessel PCI had greater in-hospital mortality (36.5% vs 27.8%; adjusted odds ratio 1.54, 95% confidence interval 1.22 to 1.95). In conclusion, these data suggest that performing multivessel PCI during primary PCI for STEMI does not improve short-term survival even for patients with cardiogenic shock. These findings suggest the need for definitive studies to evaluate the utility of noninfarct-related artery PCI among patients with STEMI.

Contemporary issues on clopidogrel therapy

In this paper, data from available studies regarding some contemporary issues on clopidogrel therapy are analyzed. In particular, the following clinical questions have been considered and addressed: (a) Is early clopidogrel treatment needed in patients with acute coronary syndromes treated medically or undergoing percutaneous coronary intervention (PCI)? (b) What is the optimal clopidogrel loading dose in patients undergoing PCI? (c) Is pre-treatment with clopidogrel before PCI needed, or can clopidogrel loading be given in the catheter laboratory before intervention, but after coronary anatomy is known? (d) What is the optimal clopidogrel strategy in patients on chronic clopidogrel therapy undergoing PCI? (e) Does the degree of clopidogrel response influence clinical outcome in patients undergoing PCI?

Bleeding in Patients Undergoing Percutaneous Coronary Intervention

Background— Bleeding in patients undergoing percutaneous coronary intervention (PCI) is associated with increased morbidity, mortality, length of hospitalization, and cost. We identified baseline clinical characteristics associated with bleeding complications after PCI and developed a simplified, clinically useful algorithm to predict patient risk.

Methods and Results— Data were analyzed from 302 152 PCI procedures performed at 440 US centers participating in the National Cardiovascular Data Registry. As defined by the National Cardiovascular Data Registry, bleeding required transfusion, prolonged hospital stay, and/or a drop in hemoglobin >3.0 g/dL from any location, including percutaneous entry site, retroperitoneal, gastrointestinal, genitourinary, and other/unknown location. Bleeding complications occurred in 2.4% of patients. From the best-fitting model consisting of 15 clinical elements associated with post-PCI bleeding in a random 80% training cohort, we developed a parsimonious risk algorithm. Predictors of bleeding included age, gender, previous heart failure, glomerular filtration rate, peripheral vascular disease, no previous PCI, New York Heart Association/Canadian Cardiovascular Society Functional Classification class IV heart failure, ST-elevation myocardial infarction, non–ST-elevation myocardial infarction, and cardiogenic shock. The parsimonious model was validated in the remaining 20% of the population (c-statistic, 0.72) and in clinically relevant subgroups of patients. This simplified model was used to derive a clinical risk algorithm, with larger numbers corresponding with greater risk. In 3 categories, bleeding rates were greater in patients with higher estimates (≤7, 0.7%; 8 to 17, 1.8%; ≥18, 5.1%).

Conclusions— This report identifies baseline clinical factors associated with bleeding and proposes a clinically useful algorithm to estimate bleeding risk. This model is potentially actionable in altering therapeutic decision making and improving outcomes in patients undergoing PCI.

Balancing myocardial ischemic and bleeding risks in patients with non-ST-segment elevation myocardial infarction

Achieving an appropriate balance of anti-ischemic efficacy versus bleeding risk with antiplatelet and anticoagulant agents demands an accurate estimation of risks. Although traditional risk stratification is available to decrease complications, and various methods of stratifying these risks have been proposed and validated, the stratification of bleeding risk is in its infancy. However, no model currently available permits the simultaneous estimation of these risks. Ischemic risk may be determined using 1 of several validated models, followed by the estimation of bleeding risk according to known risk factors. After selecting appropriate pharmacotherapy on the basis of the stratification of these risks, attention must be paid to proper dosing according to individual risk factors and patient, clinical, and technical variables. The aim of this study was to examine risk stratification models for these parameters to determine clinical characteristics common to ischemia and bleeding that can be used to minimize risks. A "bleeding risk subscale" is proposed, with factors extrapolated from current ischemic risk models, to integrate ischemic mortality and bleeding risk in patients with non-ST-segment elevation acute coronary syndromes. In conclusion, a validated tool to simultaneously evaluate ischemic and bleeding risk will help determine the most well-balanced pharmacotherapy for patients with non-ST-segment elevation acute coronary syndromes.

Impact of gender and antithrombin strategy on early and late clinical outcomes in patients with non-ST-elevation acute coronary syndromes (from the ACUITY trial)

Women with non-ST-elevation acute coronary syndrome are at increased risk for ischemic and bleeding complications compared with men. We examined the impact of gender and antithrombotic therapy for non-ST-elevation acute coronary syndrome on outcomes in patients in the ACUITY trial. Patients were randomized to heparin (unfractionated or enoxaparin) plus a glycoprotein IIb/IIIa inhibitor (GPI), bivalirudin plus a GPI, or bivalirudin alone. We compared major bleeding unconnected to coronary artery bypass grafting, composite ischemia (death, myocardial infarction, or revascularization), and net clinical outcome (composite ischemia or bleeding) in (1) men versus women overall and undergoing percutaneous coronary intervention (PCI) and (2) women overall and undergoing PCI by antithrombotic strategy. Of 13,819 patients enrolled, 4,157 were women (30.1%). Women had similar 30-day composite ischemia (7% vs 8%, p = 0.07) but greater 30-day rates of major bleeding (8% vs 3% p <0.0001) and net clinical outcomes (13% vs 10% p <0.0001) than men. One-year composite ischemia and mortality was similar. In women, bivalirudin compared with heparin + GPI resulted in less 30-day major bleeding (5% vs 10%, p <0.0001) but similar composite ischemia (7% vs 6%, p = 0.15). No differences were observed in rates of 1-year composite ischemia or mortality in women who received bivalirudin versus heparin + GPI. Results were similar in women undergoing PCI. In conclusion, women had similar 30-day mortality and composite ischemia but higher net clinical adverse events due to more bleeding complications than men; 1-year mortality was similar for men and women. In women, bivalirudin monotherapy compared with a GPI-based strategy resulted in significantly decreased bleeding but similar rates of 1-year composite ischemia and mortality.

Associations of major bleeding and myocardial infarction with the incidence and timing of mortality in patients presenting with non-ST-elevation acute coronary syndromes: a risk model from the ACUITY trial

AIMS

To evaluate the associations of myocardial infarction (MI) and major bleeding with 1-year mortality. Both MI and major bleeding predict 1-year mortality in patients presenting with acute coronary syndrome (ACS). However, the risk of each of these events on the magnitude and timing of mortality has not been well studied.

METHODS AND RESULTS

A multivariable Cox regression model was developed relating 13 independent baseline predictors to 1-year mortality for 13 819 patients with moderate and high-risk ACS enrolled in the Acute Catheterization and Urgent Intervention Triage strategy trial. After adjustment for baseline predictors, Cox models with major bleeding and recurrent MI as time-updated covariates estimated the effect of these events on mortality hazard over time. Within 30 days of randomization, 705 patients (5.1%) had an MI, 645 (4.7%) had a major bleed; 524 (3.8%) died within a year. The occurrence of an MI was associated with a hazard ratio of 3.1 compared with patients not yet having an MI, after adjustment for baseline predictors. However, MI within 30 days markedly increased the mortality risk for the first 2 days after the event (adjusted hazard ratio of 17.6), but this risk declined rapidly post-infarct (hazard ratio of 1.4 beyond 1 month after the MI event). In contrast, major bleeding had a prolonged association with mortality risk (hazard ratio of 3.5) which remained fairly steady over time throughout 1 year.

CONCLUSION

After accounting for baseline predictors of mortality, major bleeds and MI have similar overall strength of association with mortality in the first year after ACS. MI is correlated with a dramatic increase in short-term risk, whereas major bleeding correlates with a more prolonged mortality risk.

Relation of periprocedural bleeding complications and long-term outcome in patients undergoing percutaneous coronary revascularization (from the Evaluation of Oral Xemilofiban in Controlling Thrombotic Events [EXCITE] Trial)

Several clinical trials have shown that antagonists of the glycoprotein IIb/IIIa receptor decreased the incidence of death, nonfatal myocardial infarction, and the need for urgent revascularization when administered immediately before or during the 24- to 48-hour period after percutaneous coronary intervention (PCI). However, these agents increased the risk of thrombocytopenia and periprocedural bleeding complications. Therefore, the relation between periprocedural bleeding complications during PCI and long-term outcome was assessed in 6,995 patients in the EXCITE trial. Periprocedural bleeding was classified as none, mild, moderate, and severe. Measured outcomes included the incidence of all-cause mortality or the composite end point (cardiovascular disease) of death, myocardial infarction, or stroke. Subjects were followed up for a median of 210 days (7 months). Mean patient age was 59.1 years, and 21.8% were women. Periprocedural bleeding complications occurred in 1,869 patients (26.7%), and blood transfusion was administered to 189 patients (2.7%). In multivariate analysis, periprocedural bleeding complications were significantly associated with increased risk of the composite outcome for mild (hazard ratio [HR] 0.80, 95% confidence interval [CI] 0.64 to 0.97), moderate (HR 2.38, 95% CI 1.78 to 3.20), and severe bleeding complications (HR 3.55, 95% CI 2.20 to 5.73) during follow-up. Also, the necessity of blood transfusion was an important predictor of the composite end point (HR 2.61, 95% CI 1.96 to 3.60). Patients in the United States were more likely to be administered a blood transfusion than non-US patients independently of cardiovascular risk factors. In conclusion, moderate and severe periprocedural bleeding complications increased the risk of mortality and incident cardiovascular events after PCI.

Baseline risk of major bleeding in non-ST-segment-elevation myocardial infarction: the CRUSADE (Can Rapid risk stratification of Unstable angina patients Suppress ADverse outcomes with Early implementation of the ACC/AHA Guidelines) Bleeding Score

BACKGROUND

Treatments for non-ST-segment-elevation myocardial infarction (NSTEMI) reduce ischemic events but increase bleeding. Baseline prediction of bleeding risk can complement ischemic risk prediction for optimization of NSTEMI care; however, existing models are not well suited for this purpose.

METHODS AND RESULTS

We developed (n=71 277) and validated (n=17 857) a model that identifies 8 independent baseline predictors of in-hospital major bleeding among community-treated NSTEMI patients enrolled in the Can Rapid risk stratification of Unstable angina patients Suppress ADverse outcomes with Early implementation of the ACC/AHA guidelines (CRUSADE) Quality Improvement Initiative. Model performance was tested by c statistics in the derivation and validation cohorts and according to postadmission treatment (ie, invasive and antithrombotic therapy). The CRUSADE bleeding score (range 1 to 100 points) was created by assignment of weighted integers that corresponded to the coefficient of each variable. The rate of major bleeding increased by bleeding risk score quintiles: 3.1% for those at very low risk (score < or = 20); 5.5% for those at low risk (score 21-30); 8.6% for those at moderate risk (score 31-40); 11.9% for those at high risk (score 41-50); and 19.5% for those at very high risk (score >50; P(trend) <0.001). The c statistics for the major bleeding model (derivation=0.72 and validation=0.71) and risk score (derivation=0.71 and validation=0.70) were similar. The c statistics for the model among treatment subgroups were as follows: > or = 2 antithrombotics=0.72; <2 antithrombotics=0.73; invasive approach=0.73; conservative approach=0.68.

CONCLUSIONS

The CRUSADE bleeding score quantifies risk for in-hospital major bleeding across all postadmission treatments, which enhances baseline risk assessment for NSTEMI care.

Risk and management of upper gastrointestinal bleeding associated with prolonged dual-antiplatelet therapy after percutaneous coronary intervention

Prolonged dual-antiplatelet therapy with aspirin and clopidogrel is mandatory after drug-eluting stent implantation because of the potential increased risk of late stent thrombosis. The concern regarding prolonged antiplatelet therapy is the increased risk of bleeding. Gastrointestinal bleeding is the most common site of bleeding and presents a serious threat to patients due to the competing risks of gastrointestinal hemorrhage and stent thrombosis. Currently, there are no guidelines and little evidence on how best to manage these patients who are at high risk of morbidity and mortality from both the bleeding itself and the consequences of achieving optimum hemostasis by interruption of antiplatelet therapy. Managing gastrointestinal bleeding in a patient who has undergone recent percutaneous coronary intervention requires balancing the risk of stent thrombosis against further catastrophic bleeding. Close combined management between gastroenterologist and cardiologist is advocated to optimize patient outcomes.

Safety of cardiac catheterization in patients with end-stage liver disease awaiting liver transplantation

Patients with end-stage liver disease (ESLD) are predisposed to bleeding complications due to thrombocytopenia, reduced synthesis of coagulation factors, and increased fibrinolytic activity. The exact incidence of vascular access site and bleeding complications related to cardiac catheterization in this group remains unknown. Eighty-eight consecutive patients with ESLD who underwent left-sided cardiac catheterization from August 2004 to February 2007 were identified. Eighty-one patients without known liver disease matched for age, gender, and body mass index who underwent left-sided cardiac catheterization during the same period were chosen as the control group. Vascular complications were defined as hematoma >5 cm, pseudoaneurysm, arteriovenous fistula, or retroperitoneal bleeding. Patients with ESLD had lower baseline mean hematocrit (32.3 +/- 6.0% vs 39.2 +/- 6.2%, p <0.001) and mean platelet count (90.1 +/- 66.3 vs 236.1 +/- 77.1 x 10(9)/L, p <0.001) compared with controls. They also had higher mean serum creatinine (1.9 +/- 1.7 vs 1.2 +/- 0.8 mg/dl, p = 0.002) and mean international normalized ratio (1.6 +/- 0.7 vs 1.1 +/- 0.2, p <0.001). There were more complicated pseudoaneurysms in the patients with liver failure (5.7% [5 of 88]), compared with 0% in controls (p = 0.029). Patients with ESLD had lower starting hemoglobin levels and greater reductions in hemoglobin after cardiac catheterization, resulting in greater need for packed red blood cell transfusion (16% vs 4%, p = 0.008), fresh frozen plasma (51.7% vs 1.2%, p <0.001), and platelet transfusions (48.3% vs 1.2%, p <0.001). Major bleeding was higher in the ESLD group (14.8% vs 3.7%, p = 0.014), driven mainly by the need for blood transfusion. In conclusion, despite severe coagulopathy, left-sided cardiac catheterization may be performed safely in this patient population, with correction of coagulopathy and meticulous attention to procedural technique.

Early invasive compared with a selective invasive strategy in women with non-ST-elevation acute coronary syndromes: a substudy of the OASIS 5 trial and a meta-analysis of previous randomized trials

AIMS

The aim of this study was to compare benefits and risks of a routine invasive compared with a selective invasive strategy in women with non-ST-elevation acute coronary syndromes.

METHODS AND RESULTS

We randomly assigned 184 women, either to a routine or to a selective invasive strategy as a substudy to the OASIS 5 trial, who were followed for 2 years. Meta-analysis of data from previous randomized trials was also done. There were no significant differences between the two treatment strategies in the primary outcome death/myocardial infarction (MI)/stroke [21.0 vs. 15.4%, HR = 1.46, 95% CI (0.73-2.94)], in the secondary outcome death/MI [18.8 vs. 14.3%, HR = 1.39, 95% CI (0.67-2.88)], or separately analysed outcomes MI [12.9 vs. 13.3%, HR = 0.95, 95% CI (0.42-2.19)] or stroke [2.3 vs. 4.4%, HR = 0.67, 95% CI (0.12-3.70)]. However, there were significantly more deaths after 1 year (8.8 vs. 1.1%, HR = 9.01, 95% CI (1.11-72.90) and a higher rate of major bleeding at 30 days [8.8 vs. 1.1%, HR = 11.45, 95% CI (1.43-91.96)] in the routine invasive strategy group. A meta-analysis including 2692 women in previous randomized trials, with a gender perspective, showed no significant difference in the composite outcome death/MI, OR = 1.18, 95% CI (0.92-1.53) but a higher mortality with a routine invasive strategy for women, OR = 1.51, 95% CI (1.00-2.29).

CONCLUSION

The rate of death, MI, or stroke in women was not different in patients treated with a routine invasive strategy compared with a selective invasive strategy, but there was a concerning trend towards higher mortality. When combined with data from previous trials, there does not appear to be a benefit of an early invasive strategy in women with ACS, which differs from the results in men. These data emphasize the lack of clear evidence in favour of an invasive strategy in women and suggest caution in extrapolating the results from men to women.

Expanding the recognition and assessment of bleeding events associated with antiplatelet therapy in primary care

Antiplatelet therapy is an evidence-based, guideline-recommended, worldwide standard of care for treatment of patients with atherothrombosis. However, clinical implementation of the guidelines is suboptimal, in part because of physician and patient nonadherence. The increased risk of bleeding associated with antiplatelet therapy is often the reason for nonadherence, and several programs have been created to increase adherence to guideline treatment recommendations. Despite the relative success of such initiatives, including Can Rapid Risk Stratification of Unstable Angina Patients Suppress Adverse Outcomes With Early Implementation of the ACC/AHA Guidelines, Guidelines Applied in Practice, and the American Heart Association's Get With the Guidelines and a Science Advisory, a current estimate is that less than 50% of atherothrombotic patients are taking antiplatelet therapies as recommended by national guidelines. A PubMed and MEDLINE search of the literature (January 1, 1983-May 15, 2008) was performed to examine the bleeding risks associated with various antiplatelet therapies. Relevant clinical trials, observational registry data, and other studies relevant to treatment and guideline recommendations were selected from articles generated through specific search terms. This comprehensive review contributes to the understanding of the benefit-to-risk ratio of antiplatelet therapy for patients with atherothrombosis.

Consequences of major bleeding in hospitalized patients with non-ST segment elevation acute coronary syndromes receiving injectable anticoagulants

OBJECTIVE

To evaluate the burden of major bleed in patients with non-ST segment elevation acute coronary syndromes (NSTE ACS) receiving injectable anticoagulation from the hospital perspective.

METHODS

Retrospective analysis of inpatient medical and pharmacy data from the Premier Perspective Comparative Database between 1/1/2003 and 3/31/2006. Hospitalized patients aged >or=18 years with a diagnosis of UA or NSTEMI who received an injectable anticoagulant agent during the same hospital stay were stratified into two cohorts: those who experienced a major bleed during hospitalization and those who did not, defined by the presence of >or=1 pre-specified ICD-9 codes. Length of hospital stay (LOS), inpatient mortality, 30-day readmissions, and hospitalization costs over 30 days were assessed between the cohorts using statistical models to control for covariates which may have impacted the outcomes.

RESULTS

Patients with a major bleed had significantly longer length of stay (13.8 days vs 5.6 days), higher readmission rates (31.3% vs 14.7%), and increased all-cause mortality (15.0% vs 4.5%) compared with patients who did not bleed. After controlling for covariates, major bleeding was significantly associated with increased length of stay, readmission rate, and mortality. Adjusted costs were $13,856 higher on average for patients with a major bleed (95% CI: $13,828-$18,884; p < 0.0001). Subanalyses conducted on patients aged >or=65 years and those undergoing invasive procedures demonstrated higher occurrence of bleed than the general population and a similar impact on outcomes assessed.

CONCLUSION

In conclusion, the study showed that patients with UA or NSTEMI who experience a major bleed have significantly longer hospital stays, higher readmission rates, increased costs, and increased mortality than those without a major bleed. These data emphasize the importance of considering the safety profile in context of the efficacy of the recommended agents. The findings from this study are limited by the retrospective study design and certain endpoints, such as readmissions, may have been underreported.

Expanding the recognition and assessment of bleeding events associated with antiplatelet therapy in primary care

Antiplatelet therapy is an evidence-based, guideline-recommended, worldwide standard of care for treatment of patients with atherothrombosis. However, clinical implementation of the guidelines is suboptimal, in part because of physician and patient nonadherence. The increased risk of bleeding associated with antiplatelet therapy is often the reason for nonadherence, and several programs have been created to increase adherence to guideline treatment recommendations. Despite the relative success of such initiatives, including Can Rapid Risk Stratification of Unstable Angina Patients Suppress Adverse Outcomes With Early Implementation of the ACC/AHA Guidelines, Guidelines Applied in Practice, and the American Heart Association's Get With the Guidelines and a Science Advisory, a current estimate is that less than 50% of atherothrombotic patients are taking antiplatelet therapies as recommended by national guidelines. A PubMed and MEDLINE search of the literature (January 1, 1983-May 15, 2008) was performed to examine the bleeding risks associated with various antiplatelet therapies. Relevant clinical trials, observational registry data, and other studies relevant to treatment and guideline recommendations were selected from articles generated through specific search terms. This comprehensive review contributes to the understanding of the benefit-to-risk ratio of antiplatelet therapy for patients with atherothrombosis.

Thrombocytopenia in patients with an acute coronary syndrome (from the Global Registry of Acute Coronary Events [GRACE])

The incidence of thrombocytopenia after hospital admission, patient and treatment characteristics, and outcomes in patients enrolled in the prospective multinational GRACE were examined. Heparin (unfractionated or low molecular weight) and glycoprotein IIb/IIIa-inhibition can be associated with immune-mediated thrombocytopenia of clinical importance. The prevalence of thrombocytopenia in patients with acute coronary syndromes (ACSs) in general and specifically related to these therapies and associated outcomes have been studied little outside of clinical trials. Patients with an ACS were stratified into 4 groups of those with heparin-induced thrombocytopenia (HIT), those with glycoprotein IIb/IIIa-associated thrombocytopenia (GAT), those with other thrombocytopenia (not diagnosed as HIT or associated with glycoprotein inhibitors), and those with no thrombocytopenia. From June 2000 to September 2007, a total of 52,647 patients with an ACS and information for platelet count were enrolled in GRACE. Of these, 152 (0.3%) were reported to develop HIT, 324 (0.6%) developed GAT, and 368 (0.7%) developed other thrombocytopenia. Patients with HIT, GAT, or other thrombocytopenia were significantly more likely to die in the hospital versus those without these diseases (adjusted odds ratio [OR] 1.94, 95% confidence interval [CI] 1.07 to 3.53; adjusted OR 3.45, 95% CI 2.35 to 5.05; and adjusted OR 2.83, 95% CI 1.97 to 4.06, respectively). They were also more likely to experience major bleeding, (re)infarction, or stroke. In conclusion, in this large multinational registry, 1.6% of patients with ACS were reported to develop thrombocytopenia, with only 0.3% being HIT. Regardless of whether patients had clinically recognized HIT, GAT, or other thrombocytopenia, all 3 groups had significantly higher rates of major bleeding, recurrent infarction, stroke, and death.

Radial versus femoral access for coronary angiography or intervention and the impact on major bleeding and ischemic events: a systematic review and meta-analysis of randomized trials

BACKGROUND

Small randomized trials have demonstrated that radial access reduces access site complications compared to a femoral approach. The objective of this meta-analysis was to determine if radial access reduces major bleeding and as a result can reduce death and ischemic events compared to femoral access.

METHODS

MEDLINE, EMBASE, and CENTRAL were searched from 1980 to April 2008. Relevant conference abstracts from 2005 to April 2008 were searched. Randomized trials comparing radial versus femoral access coronary angiography or intervention that reported major bleeding, death, myocardial infarction, and procedural or fluoroscopy time were included. A fixed-effects model was used with a random effects for sensitivity analysis.

RESULTS

Radial access reduced major bleeding by 73% compared to femoral access (0.05% vs 2.3%, OR 0.27 [95% CI 0.16, 0.45], P < .001). There was a trend for reductions in the composite of death, myocardial infarction, or stroke (2.5% vs 3.8%, OR 0.71 [95% CI 0.49-1.01], P = .058) as well as death (1.2% vs 1.8% OR 0.74 [95% CI 0.42-1.30], P = .29). There was a trend for higher rate of inability to the cross lesion with wire, balloon, or stent during percutaneous coronary intervention with radial access (4.7% vs 3.4% OR 1.29 [95% CI 0.87, 1.94], P = .21). Radial access reduced hospital stay by 0.4 days (95% CI 0.2-0.5, P = .0001).

CONCLUSIONS

Radial access reduced major bleeding and there was a corresponding trend for reduction in ischemic events compared to femoral access. Large randomized trials are needed to confirm the benefit of radial access on death and ischemic events.

Target populations and relevant therapeutic end points to further improve outcomes in NSTEACS patients

An aggressive pharmaco-interventional approach has been shown to improve long-term outcome among high-risk patients with acute coronary syndromes without ST-segment elevation (NSTEACS). However, these patients continue to represent a minority among those enrolled in clinical trials, thus precluding the possibility to further improve therapeutic efficacy. Target populations that are not adequately addressed by the majority of therapeutic trials are mainly the elderly and those with reduced renal function, who all show unfavorable outcome after an episode of NSTEACS. In order to allow comparison among different studies, a prerequisite for the planning of meaningful trials should be a uniform definition of the study end points besides mortality, particularly with reference to recurrent myocardial infarction, and rehospitalization owing to cardiovascular instability or severe bleeding. In addition to trial design issues, improvements in the regulatory rules for drug development and in hospital networking conceal significant opportunities to improve treatment of NSTEACS.

Incidence of bleeding and compliance on prolonged dual antiplatelet therapy (aspirin + thienopyridine) following drug-eluting stent implantation

Prolonged periods of dual antiplatelet therapy (DAT), i.e., aspirin plus a thienopyridine, are currently recommended to prevent late drug-eluting stent (DES) thrombosis. The aim of our study was to determine the risk and predictors of bleeding and compliance associated with such prolongation of DAT. In this observational study we examined 2,355 consecutive patients undergoing successful DES implantation at 4 hospitals in Italy from June 2002 to December 2004. Bleeding events occurring on DAT and warfarin or in the first 30 days after stent implantation were excluded. Median duration of DAT was 209 days (interquartile range 178 to 444) and only 158 patients (6.7%) prematurely discontinued DAT. The overall bleeding rate was 1.9% (45), with major bleeding in 19 (0.8%) and minor bleeding in 26 (1.1%). Independent predictors of bleeding were DAT (hazard ratio 19.8, 95% confidence interval [CI] 3.69 to 106.34, p <0.001) and age >65 years (hazard ratio 2.15, 95% CI 1.16 to 4.00, p = 0.02). In patients on DAT, the incidence rate (30 days to 18 months) of any bleeding event was 2.57 per 100 person-years (95% CI 1.85 to 3.48) and major bleeding was 1.10 per 100 person-years (95% CI 0.65 to 1.74). In conclusion, DAT after DES implantation is well tolerated and associated with a very low risk of major bleeding.

Design and rationale of CURRENT-OASIS 7: a randomized, 2 x 2 factorial trial evaluating optimal dosing strategies for clopidogrel and aspirin in patients with ST and non-ST-elevation acute coronary syndromes managed with an early invasive strategy

BACKGROUND

Antiplatelet therapy with clopidogrel and acetylsalicylic acid (ASA) reduces major cardiovascular events in patients with ST and non-ST-segment-elevation acute coronary syndromes (ACS). Recent mechanistic and clinical data suggest that higher loading and maintenance doses of clopidogrel may achieve a more rapid and greater degree of platelet inhibition that translates into improved clinical outcomes, but this is yet to be formally evaluated in an adequately powered randomized trial.

OBJECTIVES

To evaluate the efficacy and safety of (1) a higher loading and initial maintenance dose of clopidogrel compared with the standard-dose regimen and (2) high-dose ASA compared with low-dose ASA in patients with ST or non-ST-segment-elevation ACS managed with an early invasive strategy.

DESIGN

Multicenter, international, randomized, 2 x 2 factorial design trial evaluating a clopidogrel high-dose regimen (600 mg loading dose on day 1 followed by 150 mg once daily on days 2 to 7, followed by 75 mg once daily on days 8-30) compared with the standard-dose regimen (300 mg loading dose on day 1, followed by 75 mg once daily on days 2-30) and high-dose ASA (300-325 mg daily) versus low-dose ASA (75-100 mg daily) in patients with ST or non-ST-segment-elevation ACS managed with an early invasive strategy. The clopidogrel dose comparison is double-blind and the ASA dose comparison is open-label. The primary outcome is the composite of death from cardiovascular causes, myocardial (re)infarction or stroke up to day 30. The primary safety outcome is major bleeding. The sample size is 18,000 to 20,000 patients.

CONCLUSIONS

The CURRENT-OASIS 7 trial will help to define optimal dosing regimens for clopidogrel and ASA in patients with ST and non-ST-segment-elevation ACS treated with an early invasive strategy.

Clopidogrel use and bleeding after coronary artery bypass graft surgery

BACKGROUND

Short-term use of clopidogrel plus aspirin among patients with acute coronary syndrome reduces ischemic events, but concerns about coronary artery bypass graft (CABG) surgery-related bleeding limit its early use.

METHODS

Using data from 4,794 consecutive CABG procedures in the Duke Databank for Cardiovascular Disease (January 1999 to December 2003), we developed multivariable models for associations with CABG-related bleeding defined as reoperation for bleeding, red cell transfusion, and a composite of reoperation/transfusion/hematocrit drop>or=15%. We examined clopidogrel use<or=5 days versus no clopidogrel<or=5 days before CABG in each model. Models were adjusted for propensity for clopidogrel use<or=5 days.

RESULTS

Of 4,794 CABG patients, 332 (6.9%) received clopidogrel<or=5 days before CABG, 127 (2.6%) had reoperation for bleeding, 3,277 (68.4%) received red cell transfusion, and 4,387 (91.5%) had the composite outcome. After adjustment, clopidogrel use<or=5 days was not significantly associated with reoperation (odds ratio [OR] 1.24, 95% CI 0.63-2.41) or the composite end point (OR 1.23, 95% CI 0.72-2.10). Clopidogrel<or=5 days was modestly associated with red cell transfusion (OR 1.40, 95% CI 1.04-1.89) but more weakly than other factors, including which surgeon performed the procedure.

CONCLUSION

Clopidogrel administration<or=5 days before CABG was not significantly associated with reoperation for bleeding or a bleeding composite, and only weakly with red cell transfusion after surgery. The impact of withholding clopidogrel acutely in those for whom clopidogrel has proven benefits and the impact of delaying CABG to prevent bleeding among patients treated with clopidogrel should be viewed in the context of other stronger determinants of bleeding.

Percutaneous coronary intervention in patients with acute coronary syndrome: focus on bivalirudin

Previously, indirect thrombin inhibitors such as unfractionated heparin or low-molecular-weight heparin were used as a standard anticoagulation during percutaneous coronary intervention to prevent procedural thrombotic complications but at a risk of hemorrhagic complications. More recently, bivalirudin, a member of the direct thrombin inhibitor class, has been shown to have 1) predictable pharmacokinetics, 2) ability to inhibit free- and clot-bound thrombin, 3) no properties of platelet activation, 4) avoidance of heparin-induced thrombocytopenia, and 5) a significant reduction of bleeding without a reduction in thrombotic or ischemic endpoints compared to heparin and glycoprotein IIbIIIa inhibitors when used in patients presenting with acute coronary syndrome who are planned for an invasive treatment strategy.

Early use of omeprazole benefits patients with acute myocardial infarction

BACKGROUND

Bleeding complications are not uncommon in patients with acute myocardial infarction (AMI) during treatments. How to prevent the occurrence of upper gastrointestinal bleeding in AMI patients has become one of the most intractable problems. And there are conflicting data on the efficacy and complication rate of omeprazole treatment. We conducted an intervention study to determine whether using omeprazole could benefit AMI patients.

METHODS

A total of 237 patients with AMI were divided into two groups at random: omeprazole group including 114 patients and control group including 123 patients. Omeprazole 40 mg by intravenous drip was given to the patients in omeprazole group when they were admitted to the hospitals. From the second day they were given omeprazole 20 mg per day by oral administration for 7 days. In contrast, no gastric acid inhibitor was given to the patients in control group. The incidence of upper gastrointestinal bleeding, the recanalization rate and overall mortality in both groups were observed.

RESULTS

The incidence of upper gastrointestinal bleeding in omeprazole group was 5.3% (6/114) which was much lower than 14.6% (18/123) in control group (P = 0.017), but the recanalization rate had no significant difference between the two groups (P = 0.681). The overall mortality in omeprazole group was lower than that of control group (3.5% vs. 10.6%, P = 0.035).

CONCLUSIONS

Our findings suggest that early use of omeprazole in AMI patients could decrease the incidence of upper gastrointestinal bleeding and the overall mortality, without influencing the recanalization rate. Early use of omeprazole might benefit AMI patients.

Bleeding and outcome in acute coronary syndrome: insights from continuous electrocardiogram monitoring in the Integrilin and Enoxaparin Randomized Assessment of Acute Coronary Syndrome Treatment (INTERACT) Trial

BACKGROUND

Bleeding is associated with adverse outcome in acute coronary syndromes. However, the precise pathophysiologic mechanisms have not been elucidated. We sought to determine the relationship between bleeding and myocardial ischemia detected by concurrent continuous electrocardiogram (ECG) monitoring and their independent long-term prognostic significance.

METHODS

The INTERACT trial was a randomized controlled trial of enoxaparin versus unfractionated heparin in patients with high-risk non-ST-elevation acute coronary syndromes. Continuous ECG monitoring, performed after enrollment up to 96 hours, was analyzed by an automated algorithm and reviewed by a blinded cardiologist. We centrally adjudicated all bleeding and clinical events in a blinded fashion and calculated the Global Registry of Acute Coronary Events risk score (a validated predictor of mortality) for each patient.

RESULTS

Of the 746 patients enrolled, 34 (4.6%) developed major bleeding within 96 hours. After a median follow-up of 2.4 years, patients with bleeding had a higher risk of death (28.4% vs 7.3%, P < .001) and death/myocardial infarction (38.0% vs 12.9%, P < .001) compared with those without bleeding. Overall, 619 patients survived the first 96 hours with complete data on continuous ECG monitoring. Bleeding was associated with the simultaneous presence of ST-segment shifts on continuous ECG monitoring (P = .03). After adjusting for Global Registry of Acute Coronary Events risk score and myocardial ischemia detected by continuous ECG monitoring, major bleeding remained an independent predictor of death (adjusted hazard ratio = 3.48, 95% confidence interval 1.51-8.03, P = .003) and death/myocardial infarction (adjusted hazard ratio = 2.85, 95% confidence interval 1.40-5.78, P = .004).

CONCLUSIONS

Bleeding is a powerful independent predictor of poor long-term outcome, even after adjusting for other associated prognostic factors such as advanced age and renal dysfunction. Although bleeding is associated with concurrent myocardial ischemia, its adverse prognostic impact may be mediated by complex pathophysiologic mechanisms rather than myocardial ischemia alone. Our findings suggest that future investigations should focus on other biologically plausible mechanisms.

Major bleeding: management and risk reduction in acute coronary syndromes

BACKGROUND

Guidelines for the management of high-risk non ST-segment elevation acute coronary syndrome (NSTE ACS) recommend antithrombotic and antiplatelet therapy combined with an early invasive strategy. While this strategy reduces ischemic complications, it places patients at risk for bleeding complications.

OBJECTIVE

We sought to provide a narrative review of the risk factors for bleeding, risks associated with bleeding and strategies to prevent bleeding complications.

METHODS

A comprehensive literature review was performed to identify relevant evidence.

RESULTS/CONCLUSIONS

Bleeding complications in NSTE ACS are associated with adverse events and higher mortality. Prevention of bleeding complications can be achieved through judicious dosing of medications, the use of antithrombotic agents associated with a lower bleeding risk and use of the radial artery approach in patients requiring coronary intervention. Future work should focus on delineating the mechanisms underlying the bleeding-mortality relationship and developing a better understanding of the tradeoff between efficacy and safety.

Transfusion associated microchimerism: a heretofore little-recognized complication following transfusion

Potent antiplatelet and antithrombotic agents have significantly reduced mortality in the setting of acute coronary syndromes and percutaneous coronary intervention. However these agents are associated with increased bleeding which is in turn associated with adverse clinical outcomes. In many centers, transfusion is often used to correct for blood loss. Blood transfusion in the setting of acute coronary syndrome has been associated with adverse clinical outcomes including increased mortality. Transfusion associated microchimerism (TA-MC) is a newly recognized complication of blood transfusion. There is engraftment of the donor's hematopoietic stem cells in patients who then develop microchimerism. This article discusses the association of bleeding/blood transfusion with adverse outcomes and the potential role of TA-MC in clinical outcomes.

The risk of iatrogenic bleeding in acute coronary syndromes and long-term mortality

PURPOSE OF REVIEW

This review examines the association between bleeding and adverse outcomes in patients with acute coronary syndrome and explores mechanisms behind this association and strategies for reducing bleeding complications in acute coronary syndrome.

RECENT FINDINGS

Bleeding is a common complication of antithrombotic treatment in acute coronary syndrome, and major bleeding occurs in around 5% of patients. Important risk factors for major bleeding include increasing age, female sex, renal impairment, and invasive procedures. Recent studies suggest that major bleeding in patients with acute coronary syndrome is independently associated with an increase of early and long-term morbidity and mortality. This may be due to the direct effects of anaemia and hypovolaemia, the treatment modification or withdrawal, or the adverse effects of transfusion. Bleeding complications may be reduced by use of new antithrombotic agents and by improved attention to dosing with current agents.

SUMMARY

Future studies should examine the effects on overall morbidity and mortality of strategies designed to reduce bleeding complications in patients with acute coronary syndrome. There is a need to apply uniform definitions of bleeding severity. Future trials should report all clinically relevant bleeding outcomes and transfusions. Studies are needed to investigate methods to reduce the risk of bleeding, better understand mechanisms of adverse outcome after bleeding, and establish best practice for the management of bleeding including appropriate use of transfusion in patients with acute coronary syndrome.

Impact of red blood cell transfusion on clinical outcomes in patients with acute myocardial infarction

Divergent views remain regarding the safety of treating anemia with red blood cell (RBC) transfusion in patients with acute coronary syndrome (ACS). We used a prospective database to study effect of RBC transfusion in patients with acute myocardial infarction (MI; n = 2,358). Cox regression models were used to determine the association between RBC transfusion and 6-month outcomes, incorporating transfusion as a time-dependent variable. The models adjusted for baseline variables, propensity for transfusion, and nadir hemoglobin previous to the transfusion. One hundred ninety-two patients (8.1%) received RBC transfusion. Six-month mortality rates were higher in patients receiving transfusion (28.1% vs 11.7%, p <0.0001). The adjusted hazard ratio (HR) for mortality was 1.9 in transfused patients (95% confidence interval [CI] 1.3 to 2.9). Interaction between RBC transfusion and nadir hemoglobin with respect to mortality (p = 0.004) was significant. Stratified analyses showed a protective effect of transfusion in patients with nadir hemoglobin < or=8 g/dL (adjusted HR 0.13, 95% CI 0.03 to 0.65, p = 0.013). By contrast, transfusion was associated with increased mortality in patients with nadir hemoglobin >8 g/dL (adjusted HR 2.2, 95% CI 1.5 to 3.3; p <0.0001). Similar results were obtained for the composite end point of death/MI/heart failure (p for interaction = 0.04). In conclusion, RBC transfusion in patients with acute MI and hemoglobin < or =8 g/dL may be appropriate. The increased mortality observed in transfused patients with nadir hemoglobin above 8 g/dL underscores the clinical difficulty of balancing risks and benefits of RBC transfusion in the setting of ACS.