CARDIAC TROPONIN-T IN THE DIAGNOSIS AND F OLLOW-UP OF SUSPECTED MYOCARDITIS

Background and objective: Results of routine laboratory tests for demo nstrating myocardial damage in patients suspected of having myocarditi s are often negative. This study was undertaken to ascertain (1) wheth er measuring Tropinin T (cTnT) in these patients can sensitively deter mine myocardial cell death, (2) to what extent this correlates with th e findings of endomyocardial biopsy, and (3) whether measurement of cT nT can provide noninvasive assessment of the course of myocarditis. Pa tients and methods: 80 consecutive patients (52 men, 28 women) with cl inically suspected myocarditis were investigated. The main clinical sy mptoms were heart failure (n = 45), angina pectoris (n = 25) or cardia c arrhythmias (n = 10). In most patients the symptoms had developed in temporal relation to a viral infection. Coronary heart disease was ex cluded in all by coronary angiography. Interventricular septal endomyo cardial biopsies were examined histologically and immunohistologically . cTnT was measured with a highly sensitive sandwich-immunoassay. Resu lts: An increased level of cTnT (> 0.1 ng/ml) was demonstrated in 28 o f the 80 patients (35%). Myocarditis was diagnosed histologically in o nly 5 patients, but immunohistologically in 26 of 28 (93%) with a rais ed cTnT level and in 23 of 52 (44%) with a normal cTnT level. The cTnT level was more frequently elevated in patients with a brief rather th an a long history of myocarditis. After 6 months the cTnT level was el evated in only 4 of 28 patients with myocarditis, but the myocardial b iopsy showed persisting myocarditis in 14 patients. Conclusion: Measur ement of cTnT is a very sensitive way of demonstrating myocardial cell damage in patients clinically suspected of having myocarditis. Immuno histological analysis can often provide positive results even if the h istological findings are unremarkable. The sensitivity in diagnosing o f cTnT is greatest when the patient is tested shortly after the onset of symptoms.