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Aims: Magnetic resonance imaging (MRI) is often considered to be the gold standard in measuring left ventricular function and volumes. The aim of this study was to assess the agreements between standard echocardiography (standard echo), contrast echocardiography (contrast echo), single-photon emission computed tomography (SPECT), and MRI in the determination of left ventricular ejection fraction (EF) and end-diastolic volumes (EDV) in patients treated for acute ST-elevation myocardial infarction (STEMI)., Methods and Results: Standard echo, contrast echo, SPECT and MRI were performed on the same day, 3 months after STEMI in 150 patients participating in the NORwegian Study on District Treatment of ST-Elevation Myocardial Infarction (NORDISTEMI). Bland-Altman analysis of EF measured by all four imaging modalities showed generally low mean differences but wide limits of agreement. The mean EDV difference, however, was consistently higher when MRI was compared with standard echo (54.9 mL), contrast echo (41.7 mL) and SPECT (54.6 mL), and the limits of agreement were wider. The mean EDV differences between contrast echo vs. standard echo, SPECT vs. standard echo and contrast echo vs. SPECT were small., Conclusion: Our data suggest that all four imaging modalities measured EF closely similar after STEMI as demonstrated by a very small bias. The limits of agreement were however wide. EDV measured by MRI was consistently higher when compared with the other methods which may be caused by different tracing-methods and imaging principles. As echocardiography is preferable from a cost-benefit point of view, further analysis would be needed to clarify the nature of such differences.

Abstract: Background: The relationship between levels of amino-terminal pro–B-type natriuretic peptide (NT-proBNP) and left ventricular function determined by magnetic resonance imaging (MRI) in ST-segment–elevation myocardial infarction (STEMI) is largely unknown. Methods and Results: This was a substudy of the Norwegian Study on District Treatment of STEMI, in which patients received thrombolysis followed by early or late invasive strategy. NT-proBNP was measured at 3 days and 3 months after the myocardial infarction, and magnetic resonance imaging was performed after 3 months (n = 160). Log NT-proBNP levels at both time points were significantly associated with ejection fraction (EF) (r 2 values 0.25 and 0.42, respectively) as well as infarct size (r 2 values 0.38 and 0.47, respectively; P < .0001 for all, adjusted for confounders). Furthermore, receiver operating characteristic (ROC) curves used to analyze the ability of NT-proBNP to discriminate long-term low EF (≤40%) and large infarct size (≥15.7%), were significant at both time points (P < .001 for all). Pairwise comparison of the ROC curves showed a significantly better performance of NT-proBNP at 3 months compared with 3 days for discrimination of low EF (P = .023). Conclusion: Repeated measurements of NT-proBNP in STEMI patients showed that NT-proBNP levels at 3 months were more strongly associated with long-term EF and infarct size than NT-pro BNP levels after 3 days. Our data suggest that measurement of NT-proBNP 3 months after myocardial infarction is a better indicator of left ventricular function compared with NT-proBNP in the acute phase. [Copyright &y& Elsevier]

Background. In patients with the metabolic syndrome, the prevalence of cardiovascular disease, disease-related morbidity and mortality are reported to be significantly higher than in a population without the metabolic syndrome. We investigated the role of metabolic syndrome and related biomarkers as predictors of infarct size in patients with their first myocardial infarction. Methods. This was a cross-sectional sub-study from the 3 months follow-up in the NORwegian Study of DIstrict treatment of ST-Elevation Myocardial Infarction (NORDISTEMI), including 152 consecutive patients, all initially treated with thrombolysis. Infarct size after 3 months was determined by late gadolinium enhanced magnetic resonance imaging, measuring ventricular infarct volume in absolute and relative terms. Results. At 3 months, 33 patients (22%) were categorized as having metabolic syndrome. There was no significant difference in median infarct size between those presenting with and without the metabolic syndrome [relative infarct volume 9.0 (4.8, 15.1) % vs. 8.3 (2.9, 13.6)%, p = 0.34]. Adjusting for possible confounders did not alter the results essentially. Circulating levels of IL-18, CRP and PAI-I activity were significantly higher in patients with the metabolic syndrome while adiponectin concentrations were significantly lower ( p ≤ 0.01 for all). None of these variables were associated with myocardial infarct size. Conclusions. No association between the presence of metabolic syndrome and related biomarkers, and the size of the myocardial infarction was apparent in this study population. [ABSTRACT FROM AUTHOR]

Objectives: The evaluation of infarct size and left ventricular function after acute myocardial infarction is important for predicting the subsequent clinical course. This assessment can be achieved by non-invasive imaging methods, but biochemical assays are frequently used as an alternative. We investigated the ability of a single measurement of cardiac troponin T (cTnT) the third morning after onset of ST-segment elevation myocardial infarction (STEMI) to predict infarct size and left ventricular ejection fraction (LVEF). Methods: The study population consisted of 103 patients with their first STEMI treated with thrombolysis. Blood samples for determination of cTnT were drawn the third morning after onset of symptoms. Infarct size and LVEF were assessed by magnetic resonance imaging 3 months later. Results: Linear regression analysis showed a strong, significant correlation between third-day cTnT and infarct size at 3 months (r = 0.84, p < 0.0001). A significant but inverse and weaker correlation was obtained between third-day cTnT and LVEF (r = –0.63, p < 0.0001). Adjusting for age, gender, infarct location and medication changed the results marginally. Conclusions: A single cTnT value the third morning after onset of STEMI predicted the final infarct size in this group of patients with their first STEMI, and might be useful for ruling out impaired LVEF. Copyright © 2009 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]