Thrombotic events in critically ill children with myocarditis

Area of Science:

• Pediatric Cardiology
• Critical Care Medicine
• Hematology

Background:

• Children with myocarditis face risks for thrombotic events, but antithrombotic therapy use is not well-defined.
• This study investigated the incidence of thrombotic events in critically ill children with myocarditis and compared it to those with dilated cardiomyopathy.

Purpose of the Study:

• To determine the frequency of thrombotic events in critically ill children with myocarditis.
• To compare the risk of thrombotic events in children with myocarditis versus dilated cardiomyopathy.
• To identify factors associated with thrombotic events in these pediatric populations.

Main Methods:

• Retrospective chart review of children with myocarditis and dilated cardiomyopathy treated in a cardiac intensive care unit (1995-2008).
• Data collected included antithrombotic regimens, diagnoses, arrhythmias, and need for mechanical support.
• Primary outcome was the occurrence of thrombotic events, defined as intracardiac clots or thromboembolic events.

Main Results:

• Of 45 children with myocarditis, 4.4% experienced thrombotic events; 6.7% of children with dilated cardiomyopathy had events (p=1.0).
• No significant difference in thrombotic events was observed between the myocarditis and dilated cardiomyopathy groups.
• Neither antithrombotic therapy, intravenous immune globulin, arrhythmias, nor mechanical circulatory support predicted thrombotic events.

Conclusions:

• Thrombotic events occurred in approximately 6% of the combined cohort of critically ill children with myocarditis and dilated cardiomyopathy.
• The incidence of thrombotic events did not differ between inflammatory (myocarditis) and non-inflammatory (dilated cardiomyopathy) conditions.
• Etiology of acute decompensated heart failure should not be the sole factor in deciding on antithrombotic prophylaxis in children.