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Pulmonary arterial hypertension (PAH) is a complex disease involving increased resistance in the pulmonary arteries and subsequent right ventricular (RV) remodeling. Ventricular-arterial interactions are fundamental to PAH pathophysiology but are rarely captured in computational models. It is important to identify metrics that capture and quantify these interactions to inform our understanding of this disease as well as potentially facilitate patient stratification. Towards this end, we developed and calibrated two multi-scale high-resolution closed-loop computational models using open-source software: a high-resolution arterial model implemented using CRIMSON, and a high-resolution ventricular model implemented using FEniCS. Models were constructed with clinical data including non-invasive imaging and invasive hemodynamic measurements from a cohort of pediatric PAH patients. A contribution of this work is the discussion of inconsistencies in anatomical and hemodynamic data routinely acquired in PAH patients. We proposed and implemented strategies to mitigate these inconsistencies, and subsequently use this data to inform and calibrate computational models of the ventricles and large arteries. Computational models based on adjusted clinical data were calibrated until the simulated results for the high-resolution arterial models matched within 10% of adjusted data consisting of pressure and flow, whereas the high-resolution ventricular models were calibrated until simulation results matched adjusted data of volume and pressure waveforms within 10%. A statistical analysis was performed to correlate numerous data-derived and model-derived metrics with clinically assessed disease severity. Several model-derived metrics were strongly correlated with clinically assessed disease severity, suggesting that computational models may aid in assessing PAH severity.

Introduction: Anatomic repair of congenitally corrected transposition of the great arteries (ccTGA) generally poses short-term risk for presumed long-term functional benefit by restoring the left ventricle to the systemic circulation. Understanding early and late surgical outcomes is crucial for counseling patients and families. Methods: All patients with anatomic repair at a single institution from 1993-2018 were included. Follow-up data was obtained by contact with patients’ primary cardiologists. The primary outcome was long-term survival and the secondary outcome was freedom from reintervention. Univariate Cox proportional hazard model was used to identify risk factors for mortality. In-hospital mortality and morbidity were compared between the most recent (2010-2018) and past surgical eras. Results: Anatomic repair was performed in 118 patients: 64 Senning/arterial switch operations (ASO) and 54 Senning/Rastelli operations. Survival was 85%, 82%, and 70% at 1, 10, and 20 years after repair, respectively, and was significantly lower in the Senning/Rastelli group compared to Senning/ASO (Hazard ratio 3.0, p=0.01; Figure 1). Preoperative factors associated with mortality were heterotaxy syndrome (p=0.03) and right ventricular systolic dysfunction (p=0.01). During a median follow up of 9.4 years, 47 of 98 patients (48%) required surgical or catheter-based reintervention; median freedom from reintervention was 11.7 years. For the most recent era, 30 of 32 patients (94%) with Senning/ASO and 19 of 22 patients (86%) with Senning/Rastelli operations survived to hospital discharge. In-hospital morbidity was similar between eras (30% in 1993-2009 and 28% in 2010-2018, p=0.82). Conclusions: Short- and long-term outcomes are favorable following Senning/ASO. Mortality following Senning/Rastelli operations remains high, highlighting the need for careful patient selection and family counseling.

Introduction: After anatomic repair (AR) of congenitally corrected transposition of the great arteries (ccTGA), the left ventricle (LV) is re-established as the systemic ventricle. As such, LV dysfunction is an important factor in long-term patient morbidity. While predictors exist for successful AR, little is known regarding measures of LV function before and after AR, and no known predictors exist of worsening global longitudinal strain (GLS). Methods: All patients with ccTGA who survived to discharge after AR at a single institution from 2000-2018 were included. Pre-operative and discharge echocardiograms were reviewed and GLS analysis was performed. LV sphericity index was measured to determine the degree of ventricular septal shift; a lower index denotes more septal bowing into the LV. Logistic regression was used to identify factors associated with worsened GLS after AR. Results: Of 91 survivors (65% male), 51 underwent Senning/arterial switch (ASO) and 40 had Senning/Rastelli. Mean LV ejection fraction (EF) decreased from 66% to 61% after AR (p = 0.0003) with 26% having LVEF less than or equal to 55% (increased from 4% pre-op, p = 0.0003). Mean LV GLS was normal pre-op (-20.0% ± SD 4.1%) but worsened following AR (-16.5% ± 4.6%; p -18%) increased to 62% (vs 32% pre-op, p Conclusions: Following AR of ccTGA, LVEF decreases but remains in the normal range, while LV GLS detects abnormalities. Risk factors for worsening GLS include abnormal pre-op LV GLS, lower LV sphericity index, and a Senning/ASO repair. Lower LV sphericity index, or more septal shift into the LV, may represent a “less trained” LV, highlighting the need for careful patient selection for AR.

Introduction: Children with complex congenital heart disease (CHD) are at increased risk for neurodevelopmental impairments and reduced quality of life (QOL). Patients (pts) with congenitally corrected transposition of the great arteries (ccTGA) often undergo anatomic repair to make the left ventricle the systemic ventricle, with the goal of long term cardiac benefits. Understanding long-term outcomes and QOL may inform preoperative counseling and treatment strategies for ccTGA. Methods: We measured QOL using PedsQL generic and cardiac modules for pts following anatomic repair of ccTGA with Senning/Arterial Switch or Senning/Rastelli operations. Impaired QOL by the PedsQL is defined by total scores Results: Of 88 eligible pts, 56 (64%) returned surveys (29% female, median age 11.8 years). Respondents were more likely to have pre-operative arrhythmias or pacemaker implantation compared to non-respondents. Mean total PedsQL score was 72 + 19 for pt report and 75 + 18 for parent report; 22 of 56 (39%) pts had impaired QOL scores, compared to 20% impaired scores in pts with any type of CHD, previously described. Mean physical functioning score was 72 + 22 for pt report and 76 + 21 for parent report. Mean psychosocial summary score was 73 + 18 and 75 + 18 for pt and parent report, respectively. Communication was the lowest scored subscale of the Cardiac module by pt (63 + 26) and parent (66 + 31) report. The treatment II subscale addressing medication compliance was the highest scored subscale with scores of 90 + 8 for pts and 91 + 15 for parent, respectively. Longer cardiopulmonary bypass time (p = 0.01), surgical or catheter-based reintervention following hospital discharge (p = 0.02) and heart failure symptoms (p = 0.04) were associated with impaired QOL. Conclusions: After anatomic repair of ccTGA, pts are at risk of impaired QOL compared to healthy controls and to pts with a broad range of CHD. Indicators of more complex surgical and post-operative courses were associated with impaired QOL.

Introduction: Limited data exist on the electrophysiologic outcomes of patients undergoing anatomic repair (AR) for congenitally corrected transposition of the great arteries (ccTGA). AR was defined as an atrial switch procedure plus either arterial switch (ASO) or Rastelli operation. Aims: To report mid and late electrophysiologic outcomes after AR and identify risk factors for those outcomes. Methods: Single center retrospective cohort study of patients undergoing AR between 1993-2017. Data were collected from available records. Transplant-free survival to 1 year post repair was required for inclusion. Standard descriptive statistical analysis and Cox proportional hazards were used. Results: Of 85 patients included, 95% had lesions in addition to ccTGA: most commonly VSD (84%) and pulmonary stenosis or atresia (58%). Median age at AR was 1.5y (IQR 0.9-2.8) with Senning/ASO in 56%, Senning/Rastelli in 38%, and hemi-Senning/Glenn/Rastelli in 6%. During a median follow-up of 10.6y, 45 (53%) patients developed an arrhythmia requiring intervention. Atrial tachycardia (AT) in 27 (32%) or ventricular tachycardia (VT) in 11 (13%) patients required intervention at a median of 7.4y (IQR 1.6-15.3y) and 15.9y (IQR 4.5-17.9) post-AR, respectively. Treatments included chronic medications in 29 (64%), cardioversion in 15 (33%) and catheter ablation in 10 (22%). Median freedom from AT and VT was 17.3y and 25y post-AR, respectively. D-looped ventricles (p=0.03) and multiple operations prior to AR (p=0.02) were associated with increased AT risk; and native pulmonary stenosis with increased VT risk (p=0.01). Those needing heart failure/transplant referral had increased risk of both AT and VT (both p=0.04). Pacemaker was implanted for heart block and/or SND prior to or during AR in 14 (16%), immediately post-op in 9 (11%), and late (median 6y post-AR) in 24 (28%). ICDs were implanted in 5 (6% of cohort), 4 for primary prevention. No patient had an appropriate shock. Conclusions: Anatomic ccTGA repair is associated with significant electrophysiologic morbidity. AT, VT, and SND develop at a similar incidence to that reported for d-TGA patients after atrial switch. The incidence of AV block follows a similar trajectory to that of physiologically palliated ccTGA.

Objective: Transition is defined as “the process by which adolescents and young adults with chronic childhood illnesses are prepared to take charge of their lives and their health in adulthood”. We previously reported common knowledge deficits and lack of transition readiness (TR) in 13-25 year olds with congenital or acquired heart disease. The aims of this study were to re-evaluate TR in these patients at follow-up (F/U) and to examine the relationship between changes in TR and quality of life (QOL). Methods: Patients (n=106) completed the TR Assessment and Pediatric Quality of Life Inventory (PedsQL) utilizing an e-tablet, web-based format at a routine F/U clinic visit. Changes from initial to F/U scores were evaluated. Results: Median patient age was 18.7 yrs at a median F/U time of 1.02 yrs. Average perceived knowledge deficit score (% of items with no knowledge) at F/U was 18.0 ± 15.2%, decreased from 24.7 ± 16.5%, p Conclusion: While deficits in knowledge and self-management skills persist, TR assessment and recognition of deficits can improve transition readiness with improved psychosocial QOL. Routine TR assessment is important to identify transition needs. Further studies are needed to examine the relationship between TR and outcomes in young adults with heart disease.