Role of C1q complement fixing antibody assay in therapeutic plasma exchange management of pediatric cardiac antibody mediated rejection.

Pediatric cardiac transplant patients with antibody-mediated rejection (AMR) often undergo therapeutic plasma exchange (TPE) to remove pathologic donor specific antibodies (DSA). In cases where DSA persist, it is unclear how long TPE should be continued. We report a case of a 17-year-old cardiac transplant patient with AMR where use of a C1q complement fixing antibody assay helped guide TPE cessation. This report adds to the existing literature that highlights the potential clinical significance of C1q antibodies in AMR management.

Pediatric Dilated Cardiomyopathy Patients Do Not Meet Traditional Cardiac Resynchronization Criteria.

INTRODUCTION: Cardiac resynchronization therapy (CRT) is an effective device-based intervention for adults with heart failure (HF) with specific indications, based on large, multicenter randomized clinical trials. The criteria for CRT in adult HF include significant symptoms, ventricular systolic dysfunction, prolonged QRS duration, and left bundle branch block (LBBB) pattern on electrocardiogram (ECG). Despite having less data, CRT is also being widely utilized in children with HF. The shortage of evidence-based CRT criteria in pediatrics prompted us to review a cohort of children with dilated cardiomyopathy and evaluate their potential eligibility for CRT using the traditional adult criteria. METHODS: Single-center data of all pediatric patients with dilated cardiomyopathy were extracted from the heart failure registry and retrospectively reviewed. Patients who had at least 2 separate visits that included HF scoring, electrocardiogram, and echocardiogram were included. Patients who were ventricular paced were excluded. RESULTS: Data for 52 patients meeting inclusion criteria were analyzed. The mean ejection fraction was 25% on the first clinical evaluation and 27% on the second visit. No patient and 2 patients met the adult criteria for prolonged QRS on the first and second encounters, respectively. No patients had an LBBB pattern on ECG. CONCLUSIONS: None of the pediatric HF patients in our study met the published Class I criteria for CRT device therapy in adults. These findings suggest that extrapolation of adult HF data to pediatrics is not sufficient for CRT criteria. Specific guidelines for device implantation in children must be based on scientific investigation including pediatric clinical trials.

Anomalous left coronary artery from the right coronary cusp with gene positive apical hypertrophic cardiomyopathy: a case report and literature review.

In the United States, hypertrophic cardiomyopathy and coronary artery anomalies account for the leading two causes of sudden death in athletes. We present a case of a patient with an anomalous origin of the left main from the right coronary sinus with associated gene-confirmed hypertrophic cardiomyopathy. The patient underwent surgical repair with unroofing of the intramural portion of the left main coronary artery with a good result. We also review the reported cases in the medical literature describing this uncommon association between anomalous coronary artery origin and hypertrophic cardiomyopathy.

An uncommon clinical presentation of relapsing dilated cardiomyopathy with identification of sequence variations in MYNPC3, KCNH2 and mitochondrial tRNA cysteine.

We describe a young girl with dilated cardiomyopathy, long QT syndrome, and possible energy deficiency. Two major sequence changes were identified by whole exome sequencing (WES) and mitochondrial DNA analysis that were interpreted as potentially causative. Changes were identified in the KCNH2 gene and mitochondrial tRNA for cysteine. A variation was also seen in MYPBC3. Since the launch of WES as a clinically available technology in 2010, there has been concern regarding the identification of variants unrelated to the patient's phenotype. However, in cases where targeted sequencing fails to explain the clinical presentation, the underlying etiology could be more complex than anticipated. In this situation, the extensive reach of this tool helped explain both her phenotype and family history.

Analysis of clinical parameters and cardiac magnetic resonance imaging as predictors of outcome in pediatric myocarditis.

Myocarditis causes significant morbidity and mortality in pediatric patients, with potential adverse outcomes including heart failure, transplantation requirement, and/or death. The objective of this study was to determine predictors of early and late poor outcomes, defined as requirement for extracorporeal membrane oxygenation, ventricular assist device, transplantation, or death in pediatric myocarditis patients. A retrospective cohort study was conducted to evaluate pediatric myocarditis presenting over a 5-year period at a pediatric institution. Patients were identified using an institutional heart failure database and International Classification of Diseases, Ninth Revision, discharge diagnosis codes for myocarditis and confirmed by review of medical records. Data extraction included epidemiologic factors, the presenting ejection fraction (EF), initial and peak troponin levels, brain natriuretic peptide (BNP) level, pathogen identification, cardiac magnetic resonance imaging (MRI), and outcomes. Univariate and multivariate regression was performed to identify variables predictive of outcomes. Because published pediatric cardiac MRI data are sparse, whether late enhancement was associated with specific clinical variables or predictive of outcomes was also evaluated. Fifty-eight patients were identified. The mean age was 10.5 years, 64% were male, 62% were Caucasian, 15% were African-American, and 23% were Hispanic or Asian. Eighty-one percent presented at the institution <1 week after symptom onset. Presenting EFs were normal (>50%) or mildly decreased (40% to 50%) in 48%, moderately decreased (30% to 40%) in 9%, and severely decreased (<30%) in 42%. Thirty patients (52%) underwent viral studies; 17 of these (56%) had acute viral origins of myocarditis identified, including 8 with parvovirus (2 with influenza coinfection), 7 with enterovirus, 1 with Epstein-Barr virus, and 1 with cytomegalovirus. Twenty-eight percent had poor outcomes. Univariate analysis identified Hispanic or Asian race (odds ratio [OR] 4.5, p = 0.05), a severely decreased EF (OR 13, p = 0.002), initial BNP >10,000 pg/ml (OR 5.6, p = 0.01), and peak BNP >10,000 pg/ml (OR 13.65, p = 0.001) as risk factors for poor outcomes; initial and peak troponin >1 ng/ml were correlated significantly with good outcomes (OR 0.22, p = 0.04, and OR 0.26, p = 0.05, respectively). Multivariate analysis adjusting for severe EF, troponin, BNP, and cardiac MRI revealed peak BNP >10,000 ng/L (OR 27.71, p = 0.04), a severely decreased EF (OR 12.8, p = 0.03), and late enhancement on cardiac MRI (OR 24.51, p = 0.04) as risk factors for poor outcomes. Thirty-four patients underwent cardiac MRI (50% with abnormal and 50% with normal results). No significant differences were found between these groups with respect to gender, race, symptom duration, the EF, BNP, troponin, inflammation on cardiac biopsy, or pathogen identification. In conclusion, this study provides data from a large cohort of pediatric myocarditis patients. A presenting EF <30%, peak BNP >10,000 ng/L, and cardiac MRI late enhancement were identified as predictors of poor outcomes.