The American journal of cardiology
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Current guidelines recommend troponin T (TnT) as the biomarker of choice in the diagnosis of myocardial infarction. In patients with ST-elevation myocardial infarction (STEMI) however, its role in providing a measurement of infarct size and its association with survival is less well established. We sought to assess the correlation of TnT and creatine kinase-MB (CK-MB) with scintigraphically determined infarct size and to assess the predictive value of all 3 parameters on 12-month mortality. ⋯ Final infarct size at SPECT scanning better predicted mortality than peak TnT or CK-MB. In conclusion, this study is the largest investigation on the value of cardiac troponin for assessment of infarct size in acute STEMI. Compared to peak CK-MB, peak TnT shows similar correlation with scintigraphic infarct size, although scintigraphic infarct size remains a better correlate of 1-year mortality than either biomarker.
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Beta-blocker therapy is recommended after ST-segment elevation acute myocardial infarction (STEMI) in current guidelines, although its efficacy in those patients who have undergone primary percutaneous coronary intervention (PCI) has not been adequately evaluated. Of 12,824 consecutive patients who underwent sirolimus-eluting stent implantation in the J-Cypher registry, we identified 910 patients who underwent PCI within 24 hours from onset of STEMI. Three-year outcomes were evaluated according to use of β blockers at hospital discharge (349 patients in β-blocker group and 561 patients in no-β-blocker group). ⋯ No difference was observed between the β-blocker and no-β-blocker groups in mortality (6.6% vs 6.6%, p = 0.85; propensity score adjusted hazard ratio 1.10, 95% confidence interval 0.64 to 1.90, p = 0.70) or in incidence of major adverse cardiac events (all-cause death, recurrent myocardial infarction, and heart failure hospitalization, 13.5% vs 12.1%, p = 0.91; hazard ratio 1.13, 95% confidence interval 0.76 to 1.66, p = 0.53). Better outcomes were observed in the β-blocker group than in the no-β-blocker group in a subgroup of patients with LVEF ≤40% (n = 125, death 6.4% vs 17.4%, p = 0.04; major adverse cardiac events 14.5% vs 31.8%, p = 0.009). In conclusion, β-blocker therapy was not associated with better 3-year clinical outcomes in patients with STEMI who underwent primary PCI and had preserved LVEF.