ß-Blockers, heart disease and COPD: current controversies and uncertainties.

Treating people with cardiovascular disease and COPD causes significant clinician anxiety. ß-Blockers save lives in people with heart disease, specifically postinfarction and heart failure. COPD and heart disease frequently coexist and people with both disorders have particularly high cardiovascular mortality. There are concerns about giving ß-blockers to people with concomitant COPD that include reduced basal lung function, diminished effectiveness of emergency ß-agonist treatments, reduced benefit of long-acting ß-agonist treatment and difficulty in discriminating between asthma and COPD. ß-Blockers appear to reduce lung function in both the general population and those with COPD because they are poorly selective for cardiac ß1-adrenoceptors over respiratory ß2-adrenoceptors, and studies have shown that higher ß-agonist doses are required to overcome the ß-blockade. COPD and cardiovascular disease share similar environmental risks and both disease states have high adrenergic and inflammatory activation. ß-Blockers may therefore be particularly helpful in reducing cardiovascular events in this high-risk group. They may reduce the background inflammatory state, and inhibit the tachycardia and hypertension associated with both the endogenous adrenaline and high-dose ß-agonist treatment associated with acute exacerbations of COPD. Some studies have suggested no increased and, at times, reduced mortality in patients with COPD taking ß-blockers for heart disease. However, these are all observational studies and there are no randomised controlled trials. Potential ways to improve this dilemma include the development of highly ß1-selective ß-blockers or the use of non-ß-blocking heart rate reducing agents, such as ivabridine, if these are proven to be beneficial in randomised controlled trials.

Impact of a pharmacoinvasive strategy when delays to primary PCI are prolonged.

OBJECTIVES: Primary percutaneous coronary intervention (P-PCI) is the preferred reperfusion option in ST-elevation myocardial infarction, but its benefits become attenuated as time to its potential delivery becomes prolonged. Based on the STrategic Reperfusion Early After Myocardial Infarction trial, we assessed the impact of increasing time delay on outcomes in patients randomised to a pharmacoinvasive strategy (PI) or P-PCI. METHODS: Thirty-day clinical outcomes were examined according to PCI-related delay (P-RD). Data from hospitals that enrolled >10 randomised patients were used and P-RD categorised as ≤55 min, >55-97 min and >97 min. RESULTS: Composite of death/congestive heart failure/cardiogenic shock/myocardial infarction in PI and P-PCI arms occurred in 10.6% versus 10.3% (≤55 min, p=0.910); 13.9% versus 17.9% (>55-97 min, p=0.148) and 13.5% versus 16.2% (>97 min, p=0.470), respectively. While there was no worsening of outcomes for PI across the P-RD spectrum, this occurred in the P-PCI arm (p(trend)=0.038). For P-RD ≤55 min, fewer events tended to occur with P-PCI than PI. Conversely, as P-RD increased to >55 min, PI-assigned patients had better outcomes than P-PCI, suggesting an event-free advantage with PI as P-RD increased (p(interaction)=0.094). Analysing P-RD continuously showed that for every 10-min increment there was an increasing trend towards benefit among PI-assigned patients (p(interaction)=0.073). CONCLUSIONS: As P-RD increased, PI outcomes became superior to P-PCI when P-RD is prolonged and exceeds guideline-mandated times. In such circumstances, a PI strategy may provide an alternative reperfusion option. Adverse time delays for delivery of P-PCI should be considered when evaluating reperfusion strategies. TRIAL REGISTRATION NUMBER: NCT00623623.

Outcomes of a pharmacoinvasive strategy for successful versus failed fibrinolysis and primary percutaneous intervention in acute myocardial infarction (from the STrategic Reperfusion Early After Myocardial Infarction [STREAM] study).

Although a fibrinolytic pharmacoinvasive strategy is recommended for patients with ST elevation myocardial infarction (STEMI) unable to undergo timely primary percutaneous coronary intervention (PCI), there are limited data addressing outcomes specific to those with successful or unsuccessful pharmacologic reperfusions. Accordingly, we evaluated a contemporary pharmacoinvasive strategy for failed and successful reperfusions within the STrategic Reperfusion Early After Myocardial infarction study. Of 1,823 per-protocol-treated patients with STEMI, we examined clinical outcomes and angiographic and electrocardiographic metrics in 3 groups as follows: fibrinolysis requiring rescue (rescue, n = 348), fibrinolysis with scheduled angiography (scheduled, n = 516), and primary PCI (n = 927). Compared with pharmacoinvasive patients undergoing scheduled angiography, rescue patients were more likely to have anterior wall myocardial infarction, more baseline ST-segment elevation and deviation, as well as Q waves in the distribution of their ST elevation. Residual ST elevation ≥ 2 mm 30 minutes after angiography occurred in 27.9%, 7.9%, and 24.8% of patients who underwent rescue, scheduled, and primary PCI, respectively. Thirty-day composite event rates (all-cause death, cardiogenic shock, heart failure, and reinfarction) were 18.7%, 5.5%, and 13.9%; all-cause death: 6.1%, 2.1%, and 3.9%; cardiogenic shock: 7.5%, 2.0%, and 5.4%; heart failure: 11.8%, 2.3%, and 7.6%; and reinfarction: 1.5%, 1.4%, and 2.2%, for rescue, scheduled, and primary PCI, respectively. Compared with successfully reperfused patients undergoing scheduled angiography, the adjusted relative risk of the primary outcome was 2.92 (95% confidence interval 1.92 to 4.45) in rescue patients. In conclusion, pharmacoinvasive-treated patients requiring rescue angiography had greater baseline risk with more co-morbidities and worse 30-day outcomes compared with successful fibrinolytic-treated patients. Residual ST elevation after reperfusion assists in defining prognosis.

Refining clinical trial composite outcomes: an application to the Assessment of the Safety and Efficacy of a New Thrombolytic-3 (ASSENT-3) trial.

BACKGROUND: Traditional time-to-event analysis assigns equal weight to the first event in the composite end point. This is counterintuitive to many stakeholders. METHODS: We constructed weights for components of a composite efficacy end point and a net clinical outcome by including metrics of safety and efficacy and compared the weighted with the traditional approach. Through an externally validated, clinician-investigator Delphi panel, the relative severity of individual components of a composite end point (30-day death, recurrent myocardial infarction, cardiogenic shock, and congestive heart failure) was determined. The net clinical outcome was assessed through the incorporation of risk thresholds for safety events (intracranial hemorrhage and major systemic bleeding). These weights were then applied to a modified analysis of the ASSENT-3 trial. RESULTS: The weights for the efficacy composite were as follows: death, 1.0; shock, 0.5; congestive heart failure, 0.3; and recurrent myocardial infarction, 0.2. The traditional time-to-first-event approach demonstrated a comparable advantage for both enoxaparin (enox) and abciximab (abx) over unfractionated heparin (P = .05), whereas the weighted efficacy analysis suggested an advantage for enox and similar outcomes between unfractionated heparin and abx (P = .2). The apparent advantage of enox was attenuated when the net clinical outcome was examined; the apparent efficacy of abx combination therapy was also diminished by an elevated major systemic bleeding rate (P < .001). CONCLUSION: This novel approach adds an alternative dimension to treatment evaluation by more efficiently incorporating the differential value of all events in each patient. Further development and application of this approach to future trial design and analysis are warranted.

Unexplained international differences in clinical outcomes after acute myocardial infarction and fibrinolytic therapy: lessons from the Hirulog and Early Reperfusion or Occlusion (HERO)-2 trial.

BACKGROUND: Despite advances in therapy, global mortality due to acute myocardial infarction remains high. The international Hirulog and Early Reperfusion or Occlusion (HERO-2) trial of 17,073 patients with ST-segment elevation myocardial infarction provided the opportunity to explore international differences in outcomes. METHODS: Patient characteristics, treatment, and outcomes were compared across 5 diverse regions: Western countries, Latin America, Eastern Europe, Russia, and Asia. In addition, a representative sample of 1,743 screened patients was compared with enrolled patients. RESULTS: Larger percentages of eligible patients were randomized in Eastern Europe, Russia, and Asia than Western countries. These regions enrolled more patients with anterior myocardial infarction, Killip class III or IV, and late presentation (>4 hours). More patients aged >75 years were enrolled from Western countries. Overall risk levels were similar. Eastern Europe and Russia had lower rates than Western countries of coronary revascularization (2% vs 18%) and longer hospital stays (median 18 vs 7 days). Thirty-day mortality was lower in Western countries; 6.7% versus 10.2% to 13.2% elsewhere, whereas reinfarction was more frequent (3.2% vs 1.5% to 3.0%; each, P < .001). Regional mortality differences persisted after adjustment for baseline risk factors, treatments, or national health and economic statistics (each P < .001). CONCLUSIONS: The variation in mortality and other clinical outcomes across geographic regions was not adequately explained by risk factors, patterns of care, or national health statistics. Nevertheless, large international trials are a better way to assess potential new treatments across many countries than the alternative of separate smaller trials in each region.

Retrograde catheterisation vs. Doppler echocardiographic evaluation of aortic stenosis--a survey of contemporary UK practice.

UNLABELLED: Aortic stenosis (AS) is the most common indication for valve surgery. Recent data suggested an increased risk of cerebral emboli when the aortic valve is crossed to obtain 'pull-back' gradient. We conducted a large questionnaire based study to evaluate current practice in the assessment of aortic valve gradient amongst cardiologists and the preferences of cardiac surgeons in the UK. E-mail questionnaires were sent to 645 (72%) UK consultant cardiologists and to 198 (92%) UK consultant cardiac surgeons. 232 cardiologists and 52 cardiac surgeons responded. 53% of cardiologists routinely attempt to cross the valve in moderate AS while only 23% do so in severe AS. 38% of cardiologists in the age group '50+ years' cross the valve in severe AS compared to 13% in the age group '30-40 years'. Common reasons given for crossing a stenosed valve included 'to verify the echocardiographic gradient' (85%) and 'maintaining skill' (24%). 64% of cardiologists have changed their views on the necessity of crossing the valve in the last ten years. Although the majority appreciate the increased risk of crossing the valve only 18% of patients are consented differently if crossing the valve is planned. 26% of cardiac surgeons prefer the valve to be crossed to provide information on 'pull-back' gradient, 32% for LV function assessment and 14% to confirm MV competence. 92% would accept echocardiographic data alone if both the gradient and aortic valve area were available and considered correct. CONCLUSIONS: Our survey found that the practice of crossing the aortic valve has changed in the last 10 years and that younger consultant cardiologists are less likely to cross the aortic valve. Increasing confidence in echocardiographic data and potential complications of crossing the valve are implicated. 92% of cardiac surgeons do not require the valve to be crossed if the echo data is considered accurate.

Weighing up the cardiovascular benefits of thiazolidinedione therapy: the impact of increased risk of heart failure.

Type 2 diabetes and heart failure commonly occur together and this combination is associated with poor outcomes. The relationship is likely to be multifactorial and also may involve a specific, though ill-defined, diabetic cardiomyopathy. Glucose-lowering therapies may also be associated with an increased risk of heart failure. Data from recent large-scale clinical trials have drawn particular attention to the thiazolidinediones that appear to increase the risk of heart failure in patients with type 2 diabetes. Although pioglitazone therapy has been shown to decrease the risk of macrovascular events, the overall cardiovascular benefit needs to be addressed together with the apparent increase in heart failure risk. In this review, we provide appropriate context for assessing this balance from several perspectives. First, we consider the high underlying risk of heart failure already present in type 2 diabetes. Secondly, we highlight a potential distinction between genuine heart failure due to cardiac dysfunction and thiazolidinedione-associated oedema that may simply unmask previously undiagnosed cardiac dysfunction without itself having any direct impact on heart muscle. Most importantly, we emphasize the apparent lack of any long-term mortality consequences and a relative improvement in outcomes associated with thiazolidinedione-induced 'heart failure' and discuss the potential mechanisms underlying this apparent paradox. Finally, we review the current guidelines for thiazolidinedione use and heart failure and suggest potential future strategies for avoiding and/or minimizing this association.

Enhanced platelet aggregation and activation under conditions of hypothermia.

The effects on platelet function of temperatures attained during hypothermia used in cardiac surgery are controversial. Here we have performed studies on platelet aggregation in whole blood and platelet-rich plasma after stimulation with a range of concentrations of ADP, TRAP, U46619 and PAF at both 28 degrees C and 37 degrees C. Spontaneous aggregation was also measured after addition of saline alone. In citrated blood, spontaneous aggregation was markedly enhanced at 28 degrees C compared with 37 degrees C. Aggregation induced by ADP was also enhanced. Similar results were obtained in hirudinised blood. There was no spontaneous aggregation in PRP but ADP-induced aggregation was enhanced at 28 degrees C. The P2Y12 antagonist AR-C69931 inhibited all spontaneous aggregation at 28 degrees C and reduced all ADP-induced aggregation responses to small, reversible responses. Aspirin had no effect. Aggregation was also enhanced at 28 degrees C compared with 37 degrees C with low but not high concentrations of TRAP and U46619. PAF-induced aggregation was maximal at all concentrations when measured at 28 degrees C, but reversal of aggregation was seen at 37 degrees C. Baseline levels of platelet CD62P and CD63 were significantly enhanced at 28 degrees C compared with 37 degrees C. Expression was significantly increased at 28 degrees C after stimulation with ADP, PAF and TRAP but not after stimulation with U46619. Overall, our results demonstrate an enhancement of platelet function at 28 degrees C compared with 37 degrees C, particularly in the presence of ADP.

Inhibition of platelet aggregation by AZD6140, a reversible oral P2Y12 receptor antagonist, compared with clopidogrel in patients with acute coronary syndromes.

OBJECTIVES: In a substudy of DISPERSE (Dose confIrmation Study assessing anti-Platelet Effects of AZD6140 vs. clopidogRel in non-ST-segment Elevation myocardial infarction)-2, we compared the antiplatelet effects of AZD6140 and clopidogrel and assessed the effects of AZD6140 in clopidogrel-pretreated patients. BACKGROUND: Clopidogrel, in combination with aspirin, reduces cardiovascular events in patients with acute coronary syndromes (ACS). However, patients with poor inhibition of platelet aggregation with clopidogrel may be less well protected. AZD6140 is a reversible oral P2Y(12) receptor antagonist that has been studied in ACS patients in comparison with clopidogrel (DISPERSE-2 study). METHODS: Patients were randomized to receive either AZD6140 90 mg twice a day, AZD6140 180 mg twice a day, or clopidogrel 75 mg once a day for up to 12 weeks in a double-blind, double-dummy design. One-half the patients allocated AZD6140 received a 270-mg loading dose. Patients randomized to receive clopidogrel were given a 300-mg loading dose unless they had already been treated with clopidogrel. Adenosine diphosphate-induced platelet aggregation was assessed by optical aggregometry on day 1 and at 4-week intervals. RESULTS: AZD6140 inhibited platelet aggregation in a dose-dependent fashion and both doses achieved greater levels of inhibition than clopidogrel (e.g., 4 weeks, 4-h postdose [mean (+/-SD)]: clopidogrel 64% [+/-22%], AZD6140 90 mg 79% [+/-22%], AZD6140 180 mg 95% [+/-8%]. AZD6140 also produced further suppression of platelet aggregation in patients previously treated with clopidogrel. CONCLUSIONS: AZD6140 exhibited greater mean inhibition of platelet aggregation than a standard regimen of clopidogrel in ACS patients. In addition, AZD6140 further suppressed platelet aggregation in clopidogrel pretreated patients.

Pioglitazone use and heart failure in patients with type 2 diabetes and preexisting cardiovascular disease: data from the PROactive study (PROactive 08).

OBJECTIVE: PROspective pioglitAzone Clinical Trial In macroVascular Events (PROactive) enrolled patients with type 2 diabetes and preexisting cardiovascular disease. These patients were at high risk for heart failure, so any therapeutic benefit could potentially be offset by risk of associated heart failure mortality. We analyzed the heart failure cases to assess the effects of treatment on morbidity and mortality after reports of serious heart failure. RESEARCH DESIGN AND METHODS: PROactive was an outcome study in 5,238 patients randomized to pioglitazone or placebo. Patients with New York Heart Association Class II-IV heart failure at screening were excluded. A serious adverse event of heart failure was defined as heart failure that required hospitalization or prolonged a hospitalization stay, was fatal or life threatening, or resulted in persistent significant disability or incapacity. Heart failure risk was evaluated by multivariate regression. RESULTS: More pioglitazone (5.7%) than placebo patients (4.1%) had a serious heart failure event during the study (P = 0.007). However, mortality due to heart failure was similar (25 of 2,605 [0.96%] for pioglitazone vs. 22 of 2,633 [0.84%] for placebo; P = 0.639). Among patients with a serious heart failure event, subsequent all-cause mortality was proportionately lower with pioglitazone (40 of 149 [26.8%] vs. 37 of 108 [34.3%] with placebo; P = 0.1338). Proportionately fewer pioglitazone patients with serious heart failure went on to have an event in the primary (47.7% with pioglitazone vs. 57.4% with placebo; P = 0.0593) or main secondary end point (34.9% with pioglitazone vs. 47.2% with placebo; P = 0.025). CONCLUSIONS: Although the incidence of serious heart failure was increased with pioglitazone versus placebo in the total PROactive population of patients with type 2 diabetes and macrovascular disease, subsequent mortality or morbidity was not increased in patients with serious heart failure.

Secondary prevention of macrovascular events in patients with type 2 diabetes in the PROactive Study (PROspective pioglitAzone Clinical Trial In macroVascular Events): a randomised controlled trial.

BACKGROUND: Patients with type 2 diabetes are at high risk of fatal and non-fatal myocardial infarction and stroke. There is indirect evidence that agonists of peroxisome proliferator-activated receptor gamma (PPAR gamma) could reduce macrovascular complications. Our aim, therefore, was to ascertain whether pioglitazone reduces macrovascular morbidity and mortality in high-risk patients with type 2 diabetes. METHODS: We did a prospective, randomised controlled trial in 5238 patients with type 2 diabetes who had evidence of macrovascular disease. We recruited patients from primary-care practices and hospitals. We assigned patients to oral pioglitazone titrated from 15 mg to 45 mg (n=2605) or matching placebo (n=2633), to be taken in addition to their glucose-lowering drugs and other medications. Our primary endpoint was the composite of all-cause mortality, non fatal myocardial infarction (including silent myocardial infarction), stroke, acute coronary syndrome, endovascular or surgical intervention in the coronary or leg arteries, and amputation above the ankle. Analysis was by intention to treat. This study is registered as an International Standard Randomised Controlled Trial, number ISRCTN NCT00174993. FINDINGS: Two patients were lost to follow-up, but were included in analyses. The average time of observation was 34.5 months. 514 of 2605 patients in the pioglitazone group and 572 of 2633 patients in the placebo group had at least one event in the primary composite endpoint (HR 0.90, 95% CI 0.80-1.02, p=0.095). The main secondary endpoint was the composite of all-cause mortality, non-fatal myocardial infarction, and stroke. 301 patients in the pioglitazone group and 358 in the placebo group reached this endpoint (0.84, 0.72-0.98, p=0.027). Overall safety and tolerability was good with no change in the safety profile of pioglitazone identified. 6% (149 of 2065) and 4% (108 of 2633) of those in the pioglitazone and placebo groups, respectively, were admitted to hospital with heart failure; mortality rates from heart failure did not differ between groups. INTERPRETATION: Pioglitazone reduces the composite of all-cause mortality, non-fatal myocardial infarction, and stroke in patients with type 2 diabetes who have a high risk of macrovascular events.

The relationship between baseline risk and mortality in ST-elevation acute myocardial infarction treated with pharmacological reperfusion: insights from the Global Utilization of Strategies To open Occluded arteries (GUSTO) V trial.

BACKGROUND: We studied the potential interaction between baseline risk of death and treatment with either standard fibrinolytic monotherapy or combination fibrin and platelet lysis with respect to outcome of patients with ST-elevation myocardial infarction (STEMI) enrolled in the Global Utilization of Strategies To open Occluded arteries (GUSTO) V trial. METHODS: Using the Thrombolysis in Myocardial Infarction (TIMI) risk score (0-14 points) for STEMI, we analyzed the 30-day and 1-year mortality according to treatment assignment and risk category. Multivariable analysis was performed to identify the potential interactions between treatment and baseline risk. RESULTS: The TIMI risk score could be calculated in 16256 patients (98% of patients enrolled). The median score was 2 (1-4) in each treatment group (P = .07). The risk score was significantly associated with 30-day mortality (hazard ratio [HR], 1.52; 95% CI 1.47-1.56, P < .001, for each additional 1 point), as well as with 1-year mortality (HR 1.51, CI 1.47-1.55, P < .001). The treatment allocation was not significantly related to mortality, and there was no significant interaction between baseline risk score and treatment with respect to either end point. Although combination therapy significantly reduced death or reinfarction at 7 days (HR 0.69, CI 0.54-0.89, P < .01), independent of the risk score, there was no significant statistical interaction between the two (P = .29). CONCLUSION: The TIMI risk score accurately predicted early and 1-year mortality in patients with STEMI treated with pharmacological reperfusion. We did not identify any heterogeneity in the response of patients to combination therapy according to their TIMI risk score.

Prognostic implication of activated partial thromboplastin time after reteplase or half-dose reteplase plus abciximab: results from the GUSTO-V trial.

AIMS: To evaluate the relationship between activated partial thromboplastin time (aPTT) and clinical outcomes in the Global Use of Strategies to Open Occluded Coronary Arteries (GUSTO-V) trial comparing standard-dose reteplase to half-dose reteplase and abciximab. METHODS AND RESULTS: We analysed data on 11,420 patients receiving unfractionated heparin. Peak aPTT levels recorded during the hospitalization were correlated with clinical outcomes. Multivariable logistic regression models examined the relationship between peak aPTT levels and (i) moderate-to-severe bleeding, (ii) intracerebral haemorrhage, (iii) reinfarction, and (iv) 30-day mortality. Non-linear relationships were explored in the models using cubic spline functions. Higher rates of significant complications were seen in both groups when aPTT levels were <50 s or when levels were >70 s. In the combination therapy group, the relationship between aPTT levels and bleeding appeared accentuated. Reinfarction rates increased gradually as aPTT levels were >70 s in both groups, but the relationships were not statistically significant. Peak aPTT levels <50 s were associated with increased 30-day mortality even after multivariable adjustment. CONCLUSION: Peak aPTT levels <50 s and >70 s are associated with worse clinical outcomes in the modern era of fibrinolytic therapy; these relationships are different in patients receiving standard reteplase vs. combination therapy.

Lack of clopidogrel pretreatment effect on the relative efficacy of bivalirudin with provisional glycoprotein IIb/IIIa blockade compared to heparin with routine glycoprotein IIb/IIIa blockade: a REPLACE-2 substudy.

OBJECTIVES: The purpose of this study was to assess if clopidogrel pretreatment affects the relative efficacy of bivalirudin versus heparin with glycoprotein (GP) IIb/IIIa blockade for percutaneous coronary interventions (PCI). BACKGROUND: Although thienopyridine pretreatment may improve clinical outcomes with PCI, it is unknown if bivalirudin's efficacy compared with heparin is dependent upon such pretreatment. METHODS: The Randomized Evaluation in Percutaneous coronary intervention Linking Angiomax to reduced Clinical Events (REPLACE-2) trial was a double-blind, triple-dummy, randomized-controlled trial comparing heparin plus routine GP IIb/IIIa blockade (heparin group) with bivalirudin plus provisional GP IIb/IIIa blockade (bivalirudin group) during PCI. The primary end point was a composite of death, myocardial infarction (MI), urgent revascularization at 30 days, and major in-hospital bleeding. The secondary end point was a 30-day composite of death, MI, and urgent revascularization. Clopidogrel pretreatment was encouraged (300 mg loading, 75 mg/day). RESULTS: Of 6,010 patients enrolled, 5,893 received clopidogrel, with 85.8% in the bivalirudin and 84.6% in the heparin group receiving clopidogrel pretreatment. Bivalirudin (provisional GP IIb/IIIa blockade 7.2%) was noninferior to the heparin group for both primary and secondary end points. Clopidogrel pretreatment did not affect the relative efficacy of bivalirudin versus heparin with GP IIb/IIIa blockade, irrespective of pretreatment duration. Pretreatment was associated with significantly lower primary end point with bivalirudin (8.7% pretreatment vs. 12.9% no pretreatment, p = 0.007), and nonsignificantly with heparin (9.7% vs. 11.7%, respectively, p = 0.20). Multivariable models showed a trend toward lower primary and secondary end points with clopidogrel pretreatment. CONCLUSIONS: Clopidogrel pretreatment at the doses and time administered in this trial did not influence the relative efficacy of bivalirudin versus heparin plus GP IIb/IIIa blockade for PCI. However, pretreatment was associated with a trend towards lower clinical events after PCI.

Thrombolysis and adjunctive therapy in acute myocardial infarction: the Seventh ACCP Conference on Antithrombotic and Thrombolytic Therapy.

This chapter about antithrombotic therapy for acute myocardial infarction (MI) is part of the Seventh ACCP Conference on Antithrombotic and Thrombolytic Therapy: Evidence Based Guidelines. Grade 1 recommendations are strong and indicate that the benefits do, or do not, outweigh risks, burden, and costs. Grade 2 suggests that individual patients' values may lead to different choices (for a full understanding of the grading see Guyatt et al, CHEST 2004; 126:179S-187S). Among the key recommendations in this chapter are the following: For patients with ischemic symptoms characteristic of acute MI of < 12 h in duration, and ST-segment elevation or left bundle-branch block (of unknown duration) on the ECG, we recommend administration of any approved fibrinolytic agent (Grade 1A). We recommend the use of streptokinase, anistreplase, alteplase, reteplase, or tenecteplase over placebo (all Grade 1A). For patients with symptom duration < 6 h, we recommend the administration of alteplase over streptokinase (Grade 1A). For patients with known allergy or sensitivity to streptokinase, we recommend alteplase, reteplase, or tenecteplase (Grade 1A). For patients with acute posterior MI of < 12 h duration, we suggest fibrinolytic therapy (Grade 2C). In patients with any history of intracranial hemorrhage, closed head trauma, or ischemic stroke within past 3 months, we recommend against administration of fibrinolytic therapy (Grade 1C+). For patients with acute ST-segment elevation MI whether or not they receive fibrinolytic therapy, we recommend aspirin, 160 to 325 mg p.o., at initial evaluation by health-care personnel followed by indefinite therapy, 75 to 162 mg/d p.o. (both Grade 1A). In patients allergic to aspirin, we suggest use of clopidogrel as an alternative therapy to aspirin (Grade 2C). For patients receiving streptokinase, we suggest administration of either i.v. unfractionated heparin (UFH) [Grade 2C] or subcutaneous UFH (Grade 2A). For all patients at high risk of systemic or venous thromboembolism (anterior MI, pump failure, previous embolus, atrial fibrillation, or left ventricular thrombus), we recommend administration of IV UFH while receiving streptokinase (Grade 1C+).

Long-term efficacy of bivalirudin and provisional glycoprotein IIb/IIIa blockade vs heparin and planned glycoprotein IIb/IIIa blockade during percutaneous coronary revascularization: REPLACE-2 randomized trial.

CONTEXT: In the Randomized Evaluation in PCI Linking Angiomax to Reduced Clinical Events (REPLACE)-2 trial, bivalirudin with provisional glycoprotein IIb/IIIa (Gp IIb/IIIa) inhibition was found to be noninferior to heparin plus planned Gp IIb/IIIa blockade in the prevention of acute ischemic end points and was associated with significantly less bleeding by 30 days after percutaneous coronary intervention (PCI). OBJECTIVE: To determine whether the efficacy of bivalirudin remains comparable with that of heparin plus Gp IIb/IIIa blockade over 6 months and 1 year. DESIGN, SETTING, AND PARTICIPANTS: Follow-up study to 1 year of a randomized, double-blind trial conducted among 6010 patients undergoing urgent or elective PCI at 233 community or referral hospitals in 9 countries from October 2001 through August 2002. INTERVENTIONS: Patients were randomly assigned to receive intravenously bivalirudin (0.75 mg/kg bolus, 1.75 mg/kg per hour for the duration of PCI), with provisional Gp IIb/IIIa inhibition, or to receive heparin (65 U/kg bolus), with planned Gp IIb/IIIa inhibition (abciximab or eptifibatide). Both groups received daily aspirin and a thienopyridine for at least 30 days after PCI. MAIN OUTCOME MEASURES: Incidence of death, myocardial infarction, or repeat revascularization by 6 months and death by 12 months after enrollment. RESULTS: At 6 months, death occurred in 1.4% of patients in the heparin plus Gp IIb/IIIa group and in 1.0% of patients in the bivalirudin group (hazard ratio [HR], 0.70; 95% confidence interval [CI], 0.43-1.14; P =.15). Myocardial infarction occurred in 7.4% and 8.2% of patients, respectively (HR, 1.12; 95% CI, 0.93-1.34; P =.24), and repeat revascularization was required in 11.4% and 12.1% of patients, respectively (HR, 1.06; 95% CI, 0.91-1.23; P =.45). By 1 year, death occurred in 2.46% of patients treated with heparin plus Gp IIb/IIIa blockade and in 1.89% of patients treated with bivalirudin (HR, 0.78; 95% CI, 0.55-1.11; P =.16). Nonsignificant trends toward lower 1-year mortality with bivalirudin were present in all patient subgroups analyzed and were of greatest magnitude among high-risk patients. CONCLUSION: Long-term clinical outcome with bivalirudin and provisional Gp IIb/IIIa blockade is comparable with that of heparin plus planned Gp IIb/IIIa inhibition during contemporary PCI.

Oral ximelagatran for secondary prophylaxis after myocardial infarction: the ESTEEM randomised controlled trial.

BACKGROUND: Despite important advances in treatment, the risk of recurrent ischaemic events is high both early and late after an acute coronary syndrome. We aimed to assess the effectiveness of ximelagatran and acetylsalicylic acid for prevention of death, non-fatal myocardial infarction, and severe recurrent ischaemia after a recent myocardial infarction. METHODS: In this placebo-controlled, double-blind, multicentre, multinational dose-guiding study we assessed 1883 patients who had had recent ST-elevation or non-ST-elevation myocardial infarction. Within 14 days after the index event we randomised the participants in the proportions 1/1/1/1/2 to oral ximelagatran at doses of 24 mg, 36 mg, 48 mg, or 60 mg twice daily, or placebo, respectively for 6 months. All patients received acetylsalicylic acid 160 mg once daily. The primary efficacy outcome was the dose response of ximelagatran by comparison with placebo for the occurrence of all-cause death, non-fatal myocardial infarction, and severe recurrent ischaemia. Analysis was by intention to treat. FINDINGS: Oral ximelagatran significantly reduced the risk for the primary endpoint compared with placebo from 16.3% (102 of 638) to 12.7% (154 of 1245) (hazard ratio 0.76, 95% CI 0.59-0.98, p=0.036) for the combined ximelagatran groups versus placebo. There was no indication of a dose response between the ximelagatran groups. Major bleeding events were rare, 1.8% (23 of 1245) and 0.9% (six of 638) (hazard ratio 1.97, 95% CI 0.80-4.84) in the combined ximelagatran and placebo groups, respectively. We recorded no serious clinically adverse outcomes judged related to the investigational drug. INTERPRETATION: Oral direct thrombin inhibition with ximelagatran and acetylsalicylic acid is more effective than acetylsalicylic acid alone in preventing major cardiovascular events during 6 months of treatment in patients who have had a recent myocardial infarction.