Background: There are few data concerning prognostic markers of acute myocarditis. The purpose of this study was to assess the prognostic value of initial measurements of creatine kinase (CK), cardiac troponin I (cTnI) and myoglobin as regards late recovery of the left ventricular ejection fraction on follow-up.
Methods: A total of 22 patients (53+/-15 years old, 11 female) with acute myocarditis were followed up in a prospective observational study. Of these, 11 (50%) showed a history of acute infection prior to hospitalisation and seven (32%) had pericardial effusion. The median ejection fraction during the acute phase was 47+/-17%; after a mean follow-up of 119+/-163 days it improved to 60+/-9% (P<0.001). Considering maximal CK-rise values of 641+/-961 U/l (P=0.38), cTnI-rise values of 3.7+/-8.6 microg/l (P=0.16) and myoglobin values of 7.4+/-12 nmol/l (P=0.69), there was no correlation between initial cardiac enzyme levels and the initial and late left ventricular ejection fraction.
Conclusion: After acute myocarditis, there is late recovery of left ventricular ejection fraction, which is independent of the initial myocardial damage measured by cardiac enzyme release.