Changes in Prognosis of Heterotaxy Syndrome Over Time.

BACKGROUND: Long-term outcomes in heterotaxy syndrome (HS) are poorly described. Some reports suggest improved survival in the recent era, whereas others do not. We sought to describe long-term outcomes and assess whether outcomes have changed over time. METHODS: Patients with HS born between 1985 and 2014 who had cardiac care (except initial palliation) at our institution were divided into 4 birth eras and survival over time was compared. Independent risk factors for mortality were identified by using Cox proportional hazards regression. In patients who underwent surgery, association between surgical pathway (univentricular versus biventricular repair) and mortality after adjusting for baseline confounders was evaluated. A risk stratification model was created by using classification and regression analysis. RESULTS: Among 264 patients, 118 (44.7%) had asplenia and 146 (55.3%) had polysplenia syndrome. Overall mortality was 40.2% (n = 106), with median follow-up of 10.2 years (longest 31.5 years). In multivariable analysis, pulmonary vein stenosis, coarctation, univentricular circulation, asplenia phenotype, and at least mild atrioventricular valve regurgitation at presentation were associated with mortality, whereas birth era was not. Among patients who underwent surgery, univentricular repair remained associated with mortality after adjustment. In classification and regression analysis, patients with biventricular circulation (especially those with polysplenia) had lower mortality than those with univentricular circulation. CONCLUSIONS: In this large retrospective study of HS, outcomes remain poor and have not improved since the early 1990s. We identified risks factors associated with earlier mortality and found that those with univentricular circulation and totally anomalous pulmonary venous connection had the worst prognosis. Survival was higher in those with biventricular circulation.

Determinants of Resource Utilization in a Tertiary Pediatric and Congenital Echocardiographic Laboratory.

We sought to determine the relation between technical charges for transthoracic echocardiograms (TTE) and total time for study completion (TT), identify factors associated with high TT, and create a scoring system to predict high TT studies. We analyzed a quality improvement database that prospectively tracked patient flow through TTEs in our laboratory for 3 consecutive months. The performing sonographer or fellow recorded TT and its components for every study. Patient and scan characteristics were abstracted from the clinical database and technical charges from the financial database. Factors independently associated with high TT (top quartile ≥85 minutes) were identified in 1,686 studies and validated in the remaining 847 studies. Median age was 7.8 years (0 to 77.9) and median TT was 65 minutes (14 to 370 minutes). Charges correlated poorly with TT (r = 0.2). Multivariate analysis identified several independent factors associated with high TT. The final model had an area under the curve of 0.78 in the development sample and 0.75 in the validation sample. On the basis of the final model, we developed a risk score for TT ≥85 minutes. The prevalence of high TT was 15% in low-score studies, 51% in medium-score studies, and 81% in high-score studies. In conclusion, this is the first study to demonstrate poor correlation between technical charges for pediatric/congenital echocardiography and TT, identify risk factors for high TT, and develop a high TT risk scoring system. These data may assist in resource allocation for pediatric/congenital echocardiograms and inform reimbursement systems.

Cardiovascular magnetic resonance parameters associated with early transplant-free survival in children with small left hearts following conversion from a univentricular to biventricular circulation.

BACKGROUND: We sought to identify cardiovascular magnetic resonance (CMR) parameters associated with successful univentricular to biventricular conversion in patients with small left hearts. METHODS: Patients with small left heart structures and a univentricular circulation who underwent CMR prior to biventricular conversion were retrospectively identified and divided into 2 anatomic groups: 1) borderline hypoplastic left heart structures (BHLHS), and 2) right-dominant atrioventricular canal (RDAVC). The primary outcome variable was transplant-free survival with a biventricular circulation. RESULTS: In the BHLHS group (n = 22), 16 patients (73%) survived with a biventricular circulation over a median follow-up of 40 months (4-84). Survival was associated with a larger CMR left ventricular (LV) end-diastolic volume (EDV) (p = 0.001), higher LV-to-right ventricle (RV) stroke volume ratio (p < 0.001), and higher mitral-to-tricuspid inflow ratio (p = 0.04). For predicting biventricular survival, the addition of CMR threshold values to echocardiographic LV EDV improved sensitivity from 75% to 93% while maintaining specificity at 100%. In the RDAVC group (n = 10), 9 patients (90%) survived with a biventricular circulation over a median follow-up of 29 months (3-51). The minimum CMR values were a LV EDV of 22 ml/m² and a LV-to-RV stroke volume ratio of 0.19. CONCLUSIONS: In BHLHS patients, a larger LV EDV, LV-to-RV stroke volume ratio, and mitral-to-tricuspid inflow ratio were associated with successful biventricular conversion. The addition of CMR parameters to echocardiographic measurements improved the sensitivity for predicting successful conversion. In RDAVC patients, the high success rate precluded discriminant analysis, but a range of CMR parameters permitting biventricular conversion were identified.