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Introduction: Morphine is endorsed by all acute coronary syndromes (ACS) guidelines. However, some mechanistic studies have demonstrated that morphine impairs absorption and blunts antiplatelet effect of oral ADP receptor blockers. The clinical relevance of this interaction is controversial. Hypothesis: If morphine delays ADP receptor blocker absorption and decreases the extent of platelet inhibition, then its concomitant use with clopidogrel may increase risk of short-term ischemic events. Methods: This is a post-hoc analysis from the EARLY-ACS trial, which randomized patients with non-ST elevation ACS (NSTEACS) within 24 hours of clinical presentation to early versus delayed provisional epitifibatide. We analyzed morphine use before randomization across two separate populations: those ones that were treated with clopidogrel before randomization (5,438 patients) and those ones that were not (3,462 patients). Outcomes of interest were the composite of death, myocardial infarction, recurrent ischemia with need for urgent revascularization or thrombotic bailout during percutaneous coronary intervention at 96 hours (the same one used for the main trial) and TIMI major or minor bleeding at 120 hours. An inverse probability of treatment weighting (IPTW) propensity score model was developed to adjust for confounders. Results: A total of 1,024 patients were treated with morphine before randomization and 7,876 were not. Patients taking morphine were more likely to have heart failure at baseline, to be on nitrates and to be enrolled in North America. Results for ischemic outcomes are described at Figure 1. There was no association of prior morphine use with bleeding (OR 1.1; 95 % CI 0.79 to 1.52 for the overall cohort). Conclusions: When used together with clopidogrel, NSTEACS patients who received morphine had higher risk of short-term ischemic events. On the other hand, there was no such association when clopidogrel was not given together with morphine. [ABSTRACT FROM AUTHOR]

Objectives: Predictors of adverse outcomes following myocardial infarction (MI) are well established; however, little is known about what predicts enzymatically estimated infarct size in patients with acute ST-elevation MI. The Complement And Reduction of INfarct size after Angioplasty or Lytics trials of pexelizumab used creatine kinase (CK)-MB area under the curve to determine infarct size in patients treated with primary percutaneous coronary intervention (PCI) or fibrinolysis., Methods: Prediction of infarct size was carried out by measuring CK-MB area under the curve in patients with ST-segment elevation MI treated with reperfusion therapy from January 2000 to April 2002. Infarct size was calculated in 1622 patients (PCI=817; fibrinolysis=805). Logistic regression was used to examine the relationship between baseline demographics, total ST-segment elevation, index angiographic findings (PCI group), and binary outcome of CK-MB area under the curve greater than 3000 ng/ml., Results: Large infarcts occurred in 63% (515) of the PCI group and 69% (554) of the fibrinolysis group. Independent predictors of large infarcts differed depending on mode of reperfusion. In PCI, male sex, no prior coronary revascularization and diabetes, decreased systolic blood pressure, sum of ST-segment elevation, total (angiographic) occlusion, and nonright coronary artery culprit artery were independent predictors of larger infarcts (C index=0.73). In fibrinolysis, younger age, decreased heart rate, white race, no history of arrhythmia, increased time to fibrinolytic therapy in patients treated up to 2 h after symptom onset, and sum of ST-segment elevation were independently associated with a larger infarct size (C index=0.68)., Conclusion: Clinical and patient data can be used to predict larger infarcts on the basis of CK-MB quantification. These models may be helpful in designing future trials and in guiding the use of novel pharmacotherapies aimed at limiting infarct size in clinical practice.

Background: Prasugrel is a novel thienopyridine that reduces new or recurrent myocardial infarctions (MIs) compared with clopidogrel in patients with acute coronary syndrome undergoing percutaneous coronary intervention. This effect must be balanced against an increased bleeding risk. We aimed to characterize the effect of prasugrel with respect to the type, size, and timing of MI using the universal classification of MI., Methods and Results: We studied 13 608 patients with acute coronary syndrome undergoing percutaneous coronary intervention randomized to prasugrel or clopidogrel and treated for 6 to 15 months in the Trial to Assess Improvement in Therapeutic Outcomes by Optimizing Platelet Inhibition With Prasugrel-Thrombolysis in Myocardial Infarction (TRITON-TIMI 38). Each MI underwent supplemental classification as spontaneous, secondary, or sudden cardiac death (types 1, 2, and 3) or procedure related (Types 4 and 5) and examined events occurring early and after 30 days. Prasugrel significantly reduced the overall risk of MI (7.4% versus 9.7%; hazard ratio [HR], 0.76; 95% confidence interval [CI], 0.67 to 0.85; P<0.0001). This benefit was present for procedure-related MIs (4.9% versus 6.4%; HR, 0.76; 95% CI, 0.66 to 0.88; P=0.0002) and nonprocedural (type 1, 2, or 3) MIs (2.8% versus 3.7%; HR, 0.72; 95% CI, 0.59 to 0.88; P=0.0013) and consistently across MI size, including MIs with a biomarker peak > or =5 times the reference limit (HR. 0.74; 95% CI, 0.64 to 0.86; P=0.0001). In landmark analyses starting at 30 days, patients treated with prasugrel had a lower risk of any MI (2.9% versus 3.7%; HR, 0.77; P=0.014), including nonprocedural MI (2.3% versus 3.1%; HR, 0.74; 95% CI, 0.60 to 0.92; P=0.0069)., Conclusions: Treatment with prasugrel compared with clopidogrel for up to 15 months in patients with acute coronary syndrome undergoing percutaneous coronary intervention significantly reduces the risk of MIs that are procedure related and spontaneous and those that are small and large, including new MIs occurring during maintenance therapy.

Background: Complement, activated during myocardial ischemia and reperfusion, causes myocardial damage through multiple processes. The COMplement inhibition in Myocardial infarction treated with Angioplasty (COMMA) trial was performed to determine the effect of pexelizumab, a C5 complement inhibitor, on infarct size in patients with ST-segment-elevation myocardial infarction (MI) undergoing primary percutaneous coronary intervention., Methods and Results: In COMMA, 960 patients with MI (20% isolated inferior MI) were randomized to placebo, pexelizumab 2.0-mg/kg bolus, or pexelizumab 2.0-mg/kg bolus and 0.05-mg/kg per h infusion for 20 hours. Infarct size by creatine kinase-MB area under the curve, the primary outcome, did not differ significantly between groups (placebo median, 4393; bolus pexelizumab, 4526; bolus plus infusion pexelizumab, 4713 [ng/mL] x h; P=0.89 for bolus versus placebo; P=0.76 for bolus plus infusion versus placebo), nor did the composite of 90-day death, new or worsening heart failure, shock, or stroke (placebo, 11.1%; bolus, 10.7%; bolus plus infusion, 8.5%). The ninety-day mortality rate was significantly lower with pexelizumab bolus plus infusion (1.8% versus 5.9% with placebo; nominal P=0.014); the bolus-only group had an intermediate mortality rate (4.2%)., Conclusions: In patients with ST-elevation MI undergoing percutaneous coronary intervention, pexelizumab had no measurable effect on infarct size. However, the significant reduction in mortality suggests that pexelizumab may benefit patients through alternative novel mechanisms and provides impetus for additional investigation.