Cardiac troponin-T as a diagnostic marker in children with rheumatic carditis

ABSTRACT

Rheumatic carditis is the most serious major manifestation of acute rheumatic fever in children. Cardiac Troponin-T [cTnT] is established as a new specific marker of myocardial damage or injury. The present work was carried out to study the value of cTnT as a diagnostic marker of myocardial injury in children with rheumatic carditis, and to compare it to established parameters of myocardial injury such as creatine kinase [CK] and its MB isoenzyme. Forty-five children with acute rheumatic fever were enrolled in the study; classified into 3 groups group [A] 15 children with rheumatic carditis without cardiomegaly, group [B] 15 children with rheumatic carditis and cardiomegaly and group [C] 15 children with other rheumatic presentations. Fifteen normal healthy children were enrolled as a control group. All children included in the study were subjected to diagnostic laboratory and radiological investigations, including serum total CK, CK-MB isoenzyme% [using electrophoresis] and cTnT [by immunoassay test]. Our results showed significant elevation of cTnT, total CK and CK-MB isoenzyme in children with rheumatic carditis [groups A and B], as compared to the control group [P < 0.05]. These values were significantly higher in group [B] children [with cardiomegaly], as compared to group [A] children [P<0.05]. Also, the ideal cut-off point for cTnT was found to be 0.1 micro g/L with a sensitivity 100%, while the sensitivity for CK-MB was 86.7% and that for total CK was 53.3%.we conclude that cardiac troponin-T [cTnT] can be used as a diagnostic marker of myocardial injury in children with rheumatic carditis, with a higher sensitivity than CK and its MB isoenzyme