Cardiac Troponin-T as a Diagnostic Marker in Children with Rheumatic Carditis

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 μg/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.