title: Enzyme estimates of infarct size correlate with functional and clinical outcomes in the setting of ST-segment elevation myocardial infarction.
abstract: BACKGROUND
  Cardiac biomarkers are routinely obtained in the setting of suspected myocardial ischemia and infarction. Evidence suggests these markers may correlate with functional and clinical outcomes, but the strength of this correlation is unclear. The relationship between enzyme measures of myocardial necrosis and left ventricular performance and adverse clinical outcomes were explored.
  
  
  METHODS
  Creatine kinase (CK) and CK-MB data were analyzed, as were left ventricular ejection fraction (LVEF) by angiogram, and infarct size by single-photon emission computed tomography (SPECT) imaging in patients in 2 trials: Prompt Reperfusion In Myocardial-infarction Evolution (PRIME), and Efegatran and Streptokinase to Canalize Arteries Like Accelerated Tissue plasminogen activator (ESCALAT). Both trials evaluated efegatran combined with thrombolysis for treating acute ST-segment elevation myocardial infarction (STEMI).
  
  
  RESULTS
  Peak CK and CK area-under-the-curve (AUC) correlated significantly with SPECT-determined infarct size 5 to 10 days after enrollment. Peak CK had a statistically significant correlation with LVEF, but CK-AUC and LVEF correlation were less robust. Statistically significant correlations exist between SPECT-determined infarct size and peak CK-MB and CK-MB AUC. However, there was no correlation with LVEF for peak CK-MB and CK-MB AUC. The combined outcome of congestive heart failure and death were significantly associated with CK AUC, CK-MB AUC, peak CK, and peak CK-MB measurements.
  
  
  CONCLUSIONS
  Peak CK and CK-MB values and AUC calculations have significant correlation with functional outcomes (LVEF- and SPECT-determined infarct size) and death or CHF outcomes in the setting of STEMI. Cardiac biomarkers provide prognostic information and may serve as valid endpoint measurements for phase II clinical trials.
authors.affiliation: Department of Internal Medicine, Duke University Medical Center, Duke Clinical Research Institute, Durham, North Carolina, USA. turer001@mc.duke.edu
authors.forename: Aslan T
authors.initials: AT
authors.lastname: Turer
authors.forename: Kenneth W
authors.initials: KW
authors.lastname: Mahaffey
authors.forename: Dianne
authors.initials: D
authors.lastname: Gallup
authors.forename: W Douglas
authors.initials: WD
authors.lastname: Weaver
authors.forename: Robert H
authors.initials: RH
authors.lastname: Christenson
authors.forename: Nathan R
authors.initials: NR
authors.lastname: Every
authors.forename: E Magnus
authors.initials: EM
authors.lastname: Ohman