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At the most severe end of the spectrum of acute coronary syndromes is ST-segment elevation myocardial infarction (STEMI), which usually occurs when a fibrin-rich thrombus completely occludes an epicardial coronary artery. The diagnosis of STEMI is based on clinical characteristics and persistent ST-segment elevation as demonstrated by 12-lead electrocardiography. Patients with STEMI should undergo rapid assessment for reperfusion therapy, and a reperfusion strategy should be implemented promptly after the patient's contact with the health care system. Two methods are currently available for establishing timely coronary reperfusion: primary percutaneous coronary intervention and fibrinolytic therapy. Percutaneous coronary intervention is the preferred method but is not always available. Antiplatelet agents and anticoagulants are critical adjuncts to reperfusion. This article summarizes the current evidence-based guidelines for the diagnosis and management of STEMI. This summary is followed by a brief discussion of the role of noninvasive stress testing in the assessment of patients with acute coronary syndrome and their selection for coronary revascularization. [ABSTRACT FROM AUTHOR]

In the United States each year, >5.3 million patients present to emergency departments with chest discomfort and related symptoms. Ultimately, >1.4 million individuals are hospitalized for unstable angina and non-ST-segment elevation myocardial infarction. For emergency physicians and cardiologists alike, these patients represent an enormous challenge to accurately diagnose and appropriately treat. This update of the 2002 American College of Cardiology/American Heart Association Guidelines for the Management of Patients with Unstable Angina and Non-ST-Segment Elevation Myocardial Infarction (UA/NSTEMI) provides an evidence-based approach to the diagnosis and treatment of these patients in the emergency department, in-hospital, and after hospital discharge. Despite publication of the guidelines several years ago, many patients with UA/NSTEMI still do not receive guidelines-indicated therapy. [ABSTRACT FROM AUTHOR]

Objectives: We hypothesized that elevated B-type natriuretic peptide (BNP) levels would be associated with a greater severity of angiographic disease and a greater extent of myocardium at risk. Background: Elevations of BNP have been associated with increased risk of adverse outcomes in patients with unstable angina and non-ST-segment elevation myocardial infarction (UA/NSTEMI). Methods: Of the 2,220 patients with UA/NSTEMI enrolled in the Treat Angina with Aggrastat and Determine Cost of Therapy with an Invasive or Conservative Strategy-Thrombolysis In Myocardial Infarction-18 (TACTICS-TIMI-18) trial, 276 randomized to the invasive arm had both baseline BNP levels and angiographic core laboratory data. Patients were categorized according to their baseline BNP levels as < or =80 or >80 pg/ml. Results: A total of 233 patients (84%) had BNP levels >80 pg/ml, and 43 (16%) had admission BNP levels >80 pg/ml. Patients with BNP >80 pg/ml had tighter culprit vessel stenosis on quantitative coronary angiography (median stenosis 76% vs. 67%, p = 0.004) and a higher (slower) corrected TIMI frame count (median CTFC 43 vs. 30, p = 0.018) in the culprit vessel. The median BNP level was higher in patients with a left anterior descending coronary artery (LAD) versus non-LAD culprit lesion location (median BNP level 40 vs. 24 pg/ml, p = 0.005), and the culprit artery was more often the LAD in patients with BNP >80 pg/ml compared with < or =80 pg/ml (44% vs. 30%, p = 0.06). Conclusions: Among patients with UA/NSTEMI, elevated BNP levels are associated with tighter culprit stenosis, higher CTFC, and LAD involvement. These findings suggest that elevated BNP may be associated with a greater severity and extent of myocardial ischemic territory during the index event and may partly explain the association between elevated BNP and adverse outcomes. [ABSTRACT FROM AUTHOR]

Objectives: The study aimed to analyze the use of intensive lipid-lowering therapy (I-LLT) at discharge in a broad population of patients hospitalized with acute coronary syndrome (ACS).Background: Early and intensive statin therapy in ACS has been shown to reduce cardiovascular morbidity and mortality. Utilization and predictors of I-LLT among hospitalized ACS patients are not known.Methods: The GWTG database was analyzed for ACS-related hospitalizations from 2005 to 2009. The use of I-LLT (defined as dose of statin or combination therapy likely to produce > 50% reductions in low-density lipoprotein [LDL]) and less intensive lipid-lowering therapy (LI-LLT) at discharge was assessed. Baseline characteristics and temporal trends in LLT were compared in these 2 treatment groups.Results: Of 65,396 patients receiving LLT, only 25,036 (38.3%) were treated with an I-LLT regimen. Mean total cholesterol, LDL, and triglycerides were significantly higher in the I-LLT group. Even among those with LDL > 130 mg/dL, 50% or less received I-LLT. Predictors of I-LLT at discharge included LLT before admission, hyperlipidemia, prior coronary artery disease, increasing body mass index, and in-hospital percutaneous coronary intervention. Although there was some temporal improvement in the rate of I-LLT from 2005 to 2007, a decline in use of I-LLT was noted in 2008 and 2009. This was attributed to a sharp reduction in use of ezetimibe in combination with statin, without corresponding increases in intensive statin monotherapy.Conclusions: In a large cohort of patients admitted with ACS, most of the eligible patients were not discharged on I-LLT. These data suggest the need for better implementation of guideline-recommended intensive statin therapy in patients with ACS. [ABSTRACT FROM AUTHOR]

Background: Troponin is the preferred biomarker for risk stratification in non-ST elevation ACS. The incremental prognostic use of the initial magnitude of troponin elevation and its value in conjunction with ST-segment resolution (STRes) in ST elevation myocardial infarction (STEMI) is less well defined.Methods: Troponin T (TnT) was measured in 1,250 patients at presentation undergoing fibrinolysis for STEMI in CLARITY-TIMI 28. ST-segment resolution was measured at 90 minutes. Multivariable logistic regression was used to examine the independent association between TnT levels, STRes, and 30-day cardiovascular (CV) mortality.Results: Patients were classified into undetectable TnT at baseline (n = 594), detectable but below the median of 0.12 ng/mL (n = 330), and above the median (n = 326). Rates of 30-day CV death were 1.5%, 4.5%, and 9.5%, respectively (P < .0001). Compared with those with undetectable levels and adjusting for baseline factors, the odds ratios for 30-day CV death were 4.56 (1.72-12.08, P = .002) and 5.81 (2.29-14.73, P = .0002) for those below and above the median, respectively. When combined with STRes, there was a significant gradient of risk, and in a multivariable model both baseline TnT (P = .004) and STRes (P = .003) were significant predictors of 30-day CV death. The addition of TnT and STRes to clinical risk factors significantly improved the C-statistic (from 0.86 to 0.90, P = .02) and the integrated discriminative improvement (7.1% increase) (P = .0009).Conclusions: Baseline TnT and 90-minute STRes are independent predictors of 30-day CV death in patients with STEMI. Use of these 2 simple, readily available tools can aid clinicians in early risk stratification. [ABSTRACT FROM AUTHOR]

Glycoprotein (GP) IIb/IIIa inhibitors are beneficial in unstable angina/non-ST-segment elevation myocardial infarction (UA/NSTEMI). In large trials, the GP IIb/IIIa inhibitors tirofiban and eptifibatide were each found to reduce the risk of death or myocardial infarction (MI) in these patients at 30 days. These agents appear to be of greatest benefit in patients with a positive troponin at baseline, diabetes or ST-segment depression, recurrent angina, prior aspirin use, or a Thrombolysis In Myocardial Infarction (TIMI) risk score > or = 4. The Treat angina with Aggrastat and determine Cost of Therapy with an Invasive or Conservative Strategy (TACTICS) TIMI-18 trial was designed to compare the benefits of an early invasive versus a conservative strategy in high-risk UA/NSTEMI patients treated with GP IIb/IIIa inhibition. Patients were treated with tirofiban (for 48 h) plus aspirin and heparin and randomized to either invasive therapy (coronary angiography and revascularization when feasible) or conservative treatment (angiography only for patients with recurrent ischemia at rest or a positive stress test). A significant reduction in death or MI was demonstrated at 30 days (p = 0.02) and at 6 months (p = 0.0498). Death, MI, or rehospitalization for an acute coronary syndrome was also reduced with the invasive therapy at six months (p = 0.025). These results provide evidence to physicians that early GP IIb/IIIa inhibition in combination with a prompt invasive approach should be used more widely in UA/NSTEMI patients, particularly those at high risk. [ABSTRACT FROM AUTHOR]

Objective: To determine whether ethnic-specific differences in the prevalence of cardiovascular risk factors and outcomes exist worldwide among individuals with stable arterial disease.Patients and Methods: From December 1, 2003, to June 30, 2004, the prospective, observational REduction of Atherothrombosis for Continued Health (REACH) Registry enrolled 49,602 out-patients with coronary artery disease, cerebrovascular disease, and/or peripheral arterial disease from 7 predefined ethnic/racial groups: white, Hispanic, East Asian, South Asian, Other Asian, black, and Other (comprising any race distinct from those specified). The baseline demographic and risk factor profiles, medication use, and 2-year cardiovascular outcomes were assessed among these groups.Results: The prevalence of traditional atherothrombotic risk factors varied significantly among the ethnic/racial groups. The use of medical therapies to reduce risk was comparable among all groups. At 2-year follow-up, the rate of cardiovascular death was significantly higher in blacks (6.1%) compared with all other ethnic/racial groups (3.9%; P=.01). Cardiovascular death rates were significantly lower in all 3 Asian ethnic/racial groups (overall, 2.1%) compared with the other groups (4.5%; P<.001).Conclusion: The REACH Registry, a large international study of individuals with atherothrombotic disease, documents the important ethnic-specific differences in cardiovascular risk factors and variations in cardiovascular mortality that currently exist worldwide. [ABSTRACT FROM AUTHOR]

Objectives: This study sought to investigate the efficacy and safety of clopidogrel in women and men.Background: Previous analyses have shown sex-based differences in response to several antiplatelet medications. Little is known about the efficacy and safety of clopidogrel in women and men.Methods: This study performed a meta-analysis of all blinded randomized clinical trials comparing clopidogrel and placebo (CURE [Clopidogrel in Unstable Angina to Prevent Recurrent Events], CREDO [Clopidogrel for the Reduction of Events During Observation], CLARITY-TIMI 28 [Clopidogrel as Adjunctive Reperfusion Therapy-Thrombolysis In Myocardial Infarction 28], COMMIT [Clopidogrel and Metoprolol in Myocardial Infarction Trial], and CHARISMA [Clopidogrel for High Atherothrombotic Risk and Ischemic Stabilization, Management, and Avoidance] trials), involving a total of 79,613 patients, of whom 30% were women. The relative efficacy and safety of clopidogrel at reducing cardiovascular events (cardiovascular death, myocardial infarction [MI], or stroke) in women and men was estimated using random-effects modeling.Results: Overall, clopidogrel was associated with a highly significant 14% proportional reduction in the risk of cardiovascular events (odds ratio [OR]: 0.86; 95% confidence interval [CI]: 0.80 to 0.93), with no significant differences in treatment effect between women and men. Among the 23,533 women enrolled, there were fewer cardiovascular events in the clopidogrel group compared with the placebo group (11.0% vs. 11.8%; OR: 0.93; 95% CI: 0.86 to 1.01). In women the risk reduction with clopidogrel seemed to be greatest for MI (OR: 0.81; 95% CI: 0.70 to 0.93), with the effects on stroke (OR: 0.91; 95% CI: 0.69 to 1.21) or total death (OR: 0.99; 95% CI: 0.90 to 1.08) not statistically significant. Among the 56,091 men enrolled, there were fewer cardiovascular events in those receiving clopidogrel compared with placebo (7.8% vs. 9.0%; OR: 0.84; 95% CI: 0.78 to 0.91), and the risk reduction was significant for MI (OR: 0.83; 95% CI: 0.76 to 0.92), stroke (OR: 0.83; 95% CI: 0.71 to 0.96), and total death (OR: 0.91; 95% CI: 0.84 to 0.97). Clopidogrel increased the risk of major bleeding in both women (OR: 1.43; 95% CI: 1.15 to 1.79) and men (OR: 1.22; 95% CI: 1.05 to 1.42).Conclusions: Clopidogrel reduces the risk of cardiovascular events in both women and men. [ABSTRACT FROM AUTHOR]

Objective: We sought to determine whether elevation of plasma creatine kinase muscle-brain fraction (CK-MB) would be useful to triage patients with acute coronary syndromes (ACS) to early angiography/revascularization.Background: It is unknown whether the measurement of CK-MB is effective for triage to an aggressive management strategy.Method: Patients in the Treat Angina With Aggrastat and Determine Cost of Therapy With an Invasive or Conservative Strategy (TACTICS-TIMI) 18 study received aspirin, heparin, and tirofiban for treatment of ACS, were randomized to an invasive or a conservative strategy (angiography/revascularization between 4 and 48 h), and were followed up for a composite end point of death, myocardial infarction, or rehospitalization for ACS. Of 2,220 patients, CK-MB was elevated in 826 (37%). Of the patients with negative CK-MB, troponin T was elevated in 361 (31.2%). Event rates at 30 and 180 days were twice as high in patients with elevated CK-MB than in patients without elevated CK-MB. Both groups had similar benefit from an invasive strategy; there was no evidence of interaction between CK-MB elevation and strategy on the composite end point at 30 or 180 days. When patients were stratified according to both CK-MB and troponin status, there was evidence of a benefit in the invasive strategy among patients who were CK-negative but troponin-positive (odds ratios [95% confidence interval]: 0.13 [0.04 to 0.39] at 30 days and 0.29 [0.16 to 0.52] at 180 days).Conclusion: Patients with minimal amounts of recent onset myonecrosis but elevated risk as indicated by CK-MB and troponin, respectively, benefit most from invasive management. Determination of troponin levels yielded significant information regarding triage to an invasive strategy, particularly in CK-MB-negative patients. [ABSTRACT FROM AUTHOR]