Relationship of myocardial enzymology with myocardial damage in children with enterovirus 71 infection

Abstract

Objective To explore the diagnostic value of creatine kinase isoenzyme (CK-MB)/creatine kinase (CK) ratio for myocardial damage in children with enterovirus 71 (EV71) infection.Methods Nine hundred and ninety eight patients with EV71 infection from 2010 to 2014 were enrolled in this study.Patients with CK-MB/ CK ratio ＞5％ (n=477) were divided into myocardial damage group(n=35) and non-myocardial damage group (n=442).Routine treatment was given to all patients,and myocardial nutrition therapy was additionally given to all patients in myocardial damage group and 209 patients in non-myocardial damage group.The dynamic variation of CK-MB was investigated.The predictive value of CK-MB/CK for diagnosing myocardial damage was analysis by ROC.Results Of 998 patients with EV71 infection,47.8％ (477 patients) had higher CK-MB/CK ratio and 3.51％ (35 cases) had myocardial damage.The levels of serum CK-MB in non-myocardial damage group reached the peak on day 2 to day 3 and maintained at a fairly high level for 1-2 d and then decreased to normal in a week.The levels of serum CK-MB in myocardial damage group reached the peak on day 6 to day 8 and decreased to normal in 4 weeks.No significant differences in hospital stay and the levels of serum CK-MB on day 7 were found between patients received additional myocardial nutrition therapy whether or not (t=1.767,1.373,P＞0.05).ROC analysis showed that the area under the curve for CK-MB/CK predicting myocardial damage was 0.638 (95％CI:0.554-0.723).The sensitivity of CK-MB/CK for early prediction of myocardial damage was 76.5％ and the specificity was 53.2％ when cut-off point was 5％.Conclusions The levels of serum CK-MB in children with EV 71 infection may fluctuate following a pattern,which contributes little value to the diagnosis of myocardial damage. Key words: Enterovirus infections; Enterovirus 71; Myocardial enzymes; Myocardial damage