Prospective evaluation of the role of routine cardiac troponin T measurement to identify left ventricular ejection fraction < 40% after first myocardial infarction: Figure 1

Serial measurements of creatine kinase (CK) and its MB isoenzyme (CK-MB) and calculation of area under the curve (AUC) or peak value can be used to estimate infarct size. Peak values usually occur 20–24 hours postinfarction but release kinetics are affected by reperfusion (spontaneous or therapeutic). Regular, frequent samples must be obtained following admission, not a convenient approach for busy clinical or nursing staff. In a previous retrospective study1 we demonstrated that an angiographically determined left ventricular ejection fraction (LVEF) < 40 % could be identified by a single cardiac troponin T (cTnT) measurement at the diagnostically efficient time point of 12–24 hours from admission. We performed a larger prospective study and compared the measurement of cTnT and peak CK with early estimation of LVEF by echocardiography. Consecutive admissions to a typical UK district general hospital (DGH) with suspected acute coronary syndromes (ACS) and a final diagnosis of acute myocardial infarction (AMI) had measurement of cTnT and LVEF performed. Myocardial infarction was diagnosed according to World Health Organization criteria2 if two of the following were present: cardiac chest pain; S-T segment elevation of at least 2 mm in chest leads or 1 mm in limb leads or new …