Myocarditis in children with dilated cardiomyopathy: incidence and outcome after dual therapy immunosuppression.
BACKGROUND
The true incidence and prognosis of myocarditis in children with acute dilated cardiomyopathy (DCM) at presentation remains uncertain. This study examines the incidence of lymphocytic myocarditis in a consecutive cohort of children with acute DCM at presentation and outcome after dual therapy immunosuppression with cyclosporine and steroids.


METHODS
Twenty-nine consecutive children with acute DCM underwent early endomyocardial biopsy. Children with "definite" myocarditis comprised group I (n = 9) and were treated with cyclosporine and prednisolone. Group II (n = 2) had "borderline" myocarditis, and group III (n = 18) nonspecific histologic findings. Outcome was assessed by echocardiographic measurement of left ventricular end-diastolic dimension and fractional shortening, with follow-up endomyocardial biopsy in group I subjects.


RESULTS
Myocardial inflammation with or without myocardial necrosis (groups I and II) was present in 38% of all cases. There were no initial clinical, electrocardiographic, or echocardiographic features to distinguish patients in group I from patients in group III. At presentation, the mean +/- SEM left ventricular end-diastolic dimension and fractional score-Z scores of group I patients were 4.6 +/- 1.7 and -5.1 +/- 0.8, respectively, compared with 0.8 +/- 0.3 and -0.9 +/- 0.4, respectively, at withdrawal of immunosuppression (p < 0.001 for both). Both of these parameters did not differ significantly from normal controls at least follow up. Two group I patients had a biopsy-proven relapse after withdrawal of therapy that responded to reinstitution of immunosuppression. At latest follow-up, all nine group I patients had regained normal left ventricular function compared with four of 18 group III patients (p < 0.001).


CONCLUSIONS
Lymphocytic myocarditis is frequent in children with dilated cardiomyopathy and cannot be predicted from noninvasive investigations. The use of cyclosporine and steroids is associated with a favorable outcome, and a controlled trial of dual therapy immunosuppression in children is therefore warranted.
Kleinert
S
S
Department of Cardiology, Royal Children's Hospital, Melbourne, Australia.
Weintraub
R G
RG
Wilkinson
J L
JL
Chow
C W
CW
D000893:Anti-Inflammatory Agents / Q000627:therapeutic use; D001706:Biopsy; D002311:Cardiomyopathy, Dilated / Q000150:complications* / Q000000981:diagnostic imaging / Q000188:drug therapy / Q000473:pathology; D002675:Child, Preschool; D018849:Controlled Clinical Trials as Topic; D016572:Cyclosporine / Q000627:therapeutic use; D003971:Diastole; D004452:Echocardiography; D004562:Electrocardiography; D005500:Follow-Up Studies; D005938:Glucocorticoids / Q000627:therapeutic use; D006801:Humans; D007166:Immunosuppressive Agents / Q000627:therapeutic use*; D015994:Incidence; D007223:Infant; D008214:Lymphocytes / Q000473:pathology; D008775:Methylprednisolone / Q000627:therapeutic use; D009200:Myocardial Contraction; D009205:Myocarditis / Q000150:complications* / Q000000981:diagnostic imaging / Q000188:drug therapy / Q000473:pathology; D009206:Myocardium / Q000473:pathology; D009336:Necrosis; D011239:Prednisolone / Q000627:therapeutic use; D011379:Prognosis; D012008:Recurrence; D016896:Treatment Outcome; D016277:Ventricular Function, Left
D000893:Anti-Inflammatory Agents; D005938:Glucocorticoids; D007166:Immunosuppressive Agents; D016572:Cyclosporine; D011239:Prednisolone; D008775:Methylprednisolone