The Year in Non-ST-Segment Elevation Acute Coronary Syndromes

Comparison of Mortality Prediction by the GRACE Score, Multiple Biomarkers, and Their Combination in All-comer Patients with Acute Myocardial Infarction Undergoing Primary Percutaneous Coronary Intervention

Objective This study examined the ability of a combination of biomarkers, including N-terminal pro-B-type natriuretic peptide (N-BNP) and high-sensitivity C-reactive protein (hs-CRP), to better predict mortality than the Global Registry of Acute Coronary Events (GRACE) score in acute myocardial infarction (AMI) patients who received primary percutaneous coronary intervention (PPCI). Methods The in-hospital mortality in 754 all-comer patients with AMI who underwent successful PPCI over 8 years was examined. A receiver operating characteristic (ROC) analysis was performed to determine the in-hospital mortality in a single center. A logistic regression analysis was used to compare the predictive accuracy of the GRACE score and biomarkers. The incremental predictive value of those biomarkers beyond the GRACE score was also examined. Results The mean age was 66±13 years old, and 609 patients with ST-elevated AMI (80.8%) were included. The in-hospital mortality was 6.8%. The GRACE score (in-hospital survivor/non-survivor: 106±33/161±32; p<0.05,) and N-BNP (in-hospital survivor/non-survivor: 2,458±7,058/8,880±1,1331 pg/mL; p<0.05) were significantly lower in survivors than in non-survivors. The area under the ROC curve (AUC) of in-hospital mortality of the GRACE score was significantly higher than that of the dual-biomarker combination (0.868/0.720; p<0.05). The AUC of the combination of the GRACE score and dual-biomarkers was not significantly higher than that of the GRACE score alone (0.870/0.868; p=0.747). Conclusion The measurement of representative cardiovascular biomarkers did not provide any additional benefit for mortality prediction beyond the GRACE score in AMI patients who received PPCI.

Prognostic value of heart rate turbulence for risk assessment in patients with unstable angina and non-ST elevation myocardial infarction

Background

We sought to examine the prognostic value of heart rate turbulence derived from electrocardiographic recordings initiated in the emergency department for patients with non-ST elevation myocardial infarction (NSTEMI) or unstable angina.

Methods

Twenty-four-hour Holter recordings were started in patients with cardiac symptoms approximately 45 minutes after arrival in the emergency department. Patients subsequently diagnosed with NSTEMI or unstable angina who had recordings with ≥18 hours of sinus rhythm and sufficient data to compute Thrombolysis In Myocardial Infarction (TIMI) risk scores were chosen for analysis (n = 166). Endpoints were emergent re-entry to the cardiac emergency department and/or death at 30 days and one year.

Results

In Cox regression models, heart rate turbulence and TIMI risk scores together were significant predictors of 30-day (model chi square 13.200, P = 0.001, C-statistic 0.725) and one-year (model chi square 31.160, P < 0.001, C-statistic 0.695) endpoints, outperforming either measure alone.

Conclusion

Measurement of heart rate turbulence, initiated upon arrival at the emergency department, may provide additional incremental value in the risk assessment for patients with NSTEMI or unstable angina.

[Risk profile in acute myocardial infarction: a necessary assessment for the population's comparisons]

OBJECTIVE

The aim of this study is to show that differences of mortality, in acute myocardial infarction, observed between hospitals are not necessarily linked to a bad application of guidelines but can be linked to differences in the risk profile of the populations.

METHODS

Two populations admitted for ST and non-ST elevation myocardial infarction in the same region in 2006 were compared: the population of Chalon-sur-Saône's hospital with a standard population from the observatoire des Infarctus de Côte d'Or (RICO). The risk profile of the two populations has been realised with the risk scores GRACE, EMMACE and the Simple Risk Index (SRI).

RESULTS

The three scores are applicable for our populations according to the "C statistic". Moreover, there is a significant difference of in-hospital mortality between Chalon-sur-Saône and RICO. But, the population of Chalon-sur-Saône presents a higher risk. Finally, in-hospital rate mortality expected by the three scores is not different from the actual mortality.

CONCLUSION

GRACE, EMMACE and SRI are valid scores for the comparison of risk profile of populations in acute myocardial infarction. Comparisons between hospitals are only possible after risk adjustment of the populations.

Efficacy and safety of optimized antithrombotic therapy with aspirin, clopidogrel and enoxaparin in patients with non-ST segment elevation acute coronary syndromes in clinical practice

In randomized clinical trials enoxaparin in non ST-elevation acute coronary syndromes (NSTE-ACS) has been shown to be more effective than unfractionated heparin in preventing the combined endpoint of death and myocardial infarction. Clopidogrel in combination with aspirin reduced the combined endpoint of death, myocardial infarction and stroke in NSTE-ACS patients compared to aspirin alone. Aim of the present study was to determine the clinical impact of optimized antithrombotic therapy with enoxaparin, clopidogrel and aspirin compared to standard therapy with unfractionated heparin (UFH) and aspirin in NSTE-ACS in clinical practice. We analyzed data of 2,956 consecutive patients with NSTE-ACS and either antithrombotic therapy with enoxaparin, clopidogrel and aspirin or with aspirin and UFH, which were prospectively enrolled in the acute coronary syndromes registry (ACOS) from July 2000 until the end of November 2002. After adjustment for baseline characteristics and PCI the combined endpoint of hospital death and non-fatal reinfarctions was lower in the group with optimized antithrombotic therapy including clopidogrel, enoxaparin and aspirin compared to the control-group with aspirin and UFH (odds ratio 0.30, 95% confidence interval 0.16-0.53). There was no significant difference in major bleedings between the two treatment groups (1.5% vs. 0.9%, P = 0.35), while overall there were more bleeding complications in the group with optimized antithrombotic therapy (4.9% vs. 2.0%, P = 0.005). In clinical practice optimized antithrombotic therapy with aspirin, clopidogrel and enoxaparin in NSTE-ACS is associated with a reduction in the combined endpoint of death and non-fatal reinfarctions compared to standard therapy with aspirin and UFH without increase in major bleeding complications.

Resting magnetocardiography predicts 3-year mortality in patients presenting with acute chest pain without ST segment elevation

OBJECTIVE

Magnetocardiography (MCG) as a noninvasive, noncontact and risk-free diagnostic method predicts ischemic coronary artery disease (CAD) in patients with acute chest pain at admission with high accuracy. However, it remains unclear whether MCG findings can add prognostic information.

METHOD

A cohort of 402 consecutive patients presenting at the intensive care unit (ICU) with acute chest pain without ST segment elevation (NSTEMI) were included in a prospective registry. In order to prove the prognostic value of MCG a head-to-head comparison of the admission MCG, ECG, TnI, and ECHO tests was made.

RESULTS

In 43 patients (10.7%) the MCG could not be analyzed due to insufficient signal-to-noise ratio. Complete follow-up over a period of up to 3 years was obtained in 355 out of the 359 patients (98.9%). Age at admission was 67.2 +/- 10.3 years, 59.7% males. In the group of patients with an abnormal MCG at admission, 43 out of 249 patients (17.3%) died in the follow-up period, while in the group of patients with a normal MCG at admission only 4 out of 106 patients died (3.77%). The relative risk was 4.58 (95% confidence intervals: 1.68-12.42). A multivariate regression analysis revealed the highest mortality risk for patients with diabetes mellitus and an abnormal MCG at admission (RR = 18.0; 95% CI: 2.49-133.3).

CONCLUSION

Resting MCG at hospital admission predicts 3-year mortality in patients presenting with acute chest pain without ST segment elevation in the ECG. MCG seems to be valuable in identifying chest pain patients at highest risk.

Review of acute coronary syndrome diagnosis and management

Acute coronary syndrome (ACS) refers to a group of clinical conditions caused by myocardial ischemia including unstable angina, non-ST-segment elevation myocardial infarction (NSTEMI), and ST-segment elevation myocardial infarction (STEMI). Appropriate and accurate diagnosis has life-saving implications and requires a quick but thorough evaluation of the patient's history, physical examination, electrocardiogram, radiographic studies, and cardiac biomarkers. The management of patients with suspected or confirmed ACS continues to evolve as new evidence from clinical trials is considered and as new technology becomes available to both primary care physicians and cardiologists. Low- and intermediate-risk patients have frequently been managed in a chest pain center or in the emergency department. While stress testing with or without radionuclide imaging is the most common evaluation method, a CT angiogram is sometimes substituted. High-risk patients are often managed with an early invasive strategy involving left heart catheterization with a goal of prompt revascularization of at-risk, viable myocardium. With the increased availability of cardiac catheterization facilities, patients with STEMI are more commonly being managed with primary percutaneous coronary intervention, although thrombolysis is still used where such facilities are not immediately available. This article provides primary care physicians with a concise review of the pathophysiology, clinical evaluation, and management of ACS based on the best available evidence in 2008.

2007 update to the ACC/AHA guidelines for the management of patients with unstable angina and non-ST-segment elevation myocardial infarction: implications for emergency department practice

The American College of Cardiology and American Heart Association have updated their guidelines for the management of non-ST-segment-elevation acute coronary syndrome for the first time since 2002. In the interim, several important studies affecting choices of therapy potentially begun in the emergency department have been completed, and care patterns have changed and matured significantly. In this review, we present the new recommendations that are pertinent to emergency medicine practice and comment on their potential implementation into an evidence-based, multidisciplinary approach to the evaluation and management of this challenging patient population.

Clopidogrel resistance

Clopidogrel resistance has been used as one of the terms employed in the literature to describe different degrees of ex vivo low platelet inhibition after clopidogrel administration. In addition to the diverse nomenclature, the characterisation of clopidogrel resistance has also been problematic because different authors have given different definitions. The mechanisms responsible for this decreased platelet response are not yet clearly defined, some hypotheses have been put forward but not yet demonstrated. Although there have been no large prospective studies demonstrating that the degree of platelet inhibition is directly related to clinical outcomes, several recent studies and reports have shown an association between less platelet inhibition and more adverse events after percutaneous coronary interventions with clopidogrel therapy suggesting that clopidogrel resistance may be a marker for increased risk of recurrent cardiovascular events. Larger scale investigations are needed to support these findings.

Actualización en cardiopatía isquémica 2005

This article is a review of the main developments in acute coronary syndromes reported in publications and conference presentations in 2005. It covers the pathophysiology, secondary prevention, prognosis, and treatment of ST-segment elevation and non-ST-segment elevation acute coronary syndromes, and the latest clinical practice guidelines.