Abstract 4013: Parvovirus B19 Myocarditis Causes Significant Morbidity and Mortality in Children
Introduction: Parvovirus B19(PVB19) is now the most common cause of myocarditis, yet limited pediatric data exist. While other viruses infect myocytes, this erythrovirus targets endothelium, leading to myocardial ischemia and dysfunction in adults. We hypothesize children with PVB19 myocarditis are at risk for ischemic cardiomyopathy.
Methods: Retrospective review of patients with PCR-verified, PVB19 myocarditis at Texas Children’s and Arkansas Children’s Hospitals from 1/2005 – 8/2008 was conducted. Medical records were reviewed for symptoms, diagnostic studies, and clinical outcomes. Primary endpoints were transplant-free survival and circulatory collapse (death, mechanical support or transplant). Comparisons were performed to identify correlations between diagnostic parameters and outcomes.
Results: Of 19 patients identified, median age was 16 mos (range 6 mos-15 yrs). Most common presenting symptoms were respiratory (n=17, 89%) and GI (n=12, 63%). At admission, all patients required inotropic support and demonstrated moderate-to-severe ventricular dysfunction (median ejection fraction 24%, range 5–37%; median LVEDD z-score 4.6, range 1.1–11). T-wave abnormalities were common, with myocardial ischemia evident in 5 patients, 2 who died and 3 required transplantation. Serum BNP was elevated in all 12 patients tested (median 3652, range 348 – 8058 pg/mL), and troponin I was high in 7 of 9 patients (median 0.23, range 0.04 –14.5 ng/mL). Of 16 patients with circulatory collapse, 9 received mechanical circulatory support, 8 underwent successful cardiac transplantation and 5 died. Transplant-free survival occurred in only 6 patients (32%), 5 of whom had full recovery of function. Although most diagnostic parameters showed no correlation with clinical outcomes, LVEDD z-score tended to be lower in transplant-free survival group (3.1 vs 5.9, p=0.059).
Conclusions: PVB19 myocarditis causes significant morbidity in children. By targeting endothelium, parvovirus causes myocardial infarction and dysfunction. Although mechanical intervention can support patients in the initial stage of decompensated heart failure, many patients with PVB19 myocarditis have persistent dysfunction requiring medical therapy and transplantation.