Clinical importance of elevated CK-MB and troponin I levels in congestive heart failure

Myocyte necrosis has been considered to play a fundamental role in the pathophysiology of congestive heart failure (CHF), which has usually evolved as a consequence of depletion of compensatory mechanisms and contractile reserve of myocardium. Elevated levels of creatine kinase MB (CK-MB) and troponin I (Tn-I) have been regarded as biochemical markers of myocyte necrosis. This study was planned to investigate the specificity and sensitivity of Tn-I and CK-MB in CHF and to examine the correlation of these markers with disease severity. A total of 104 patients (38 female, 66 male; mean age, 66 y [range, 36-89]) with symptoms and signs of heart failure on admission and with a reduced left ventricular ejection fraction (EF; by transthoracic echocardiography) were labeled "the patient group," and 58 patients (40 female,18 male; mean age, 61 y [range, 34-77]) with no signs or symptoms of CHF and with a normal EF detected by transthoracic echocardiography were included in the study as "the control group." Left ventricular EFs, end-diastolic diameters, and end-systolic diameters of patients in both groups were measured. Blood samples were drawn from all patients in both groups on admission, so that levels of CK-MB and Tn-I could be measured. All patients in both groups also underwent coronary angiography. Conditions leading to elevation of CK-MB or Tn-I were considered exclusion criteria. The 2 groups failed to show any significant differences in terms of mean age and the presence of coronary artery disease, hypertension, or diabetes mellitus (P>.05). Mean EF in the patient group was lower than that in the control group (P