Abstract 15805: Longitudinal Changes in Univentricular Patients Pre-Bidirectional Cavopulmonary Connection and Pre-Fontan

Background: Little is known about serial changes in the physiology of single ventricle (SV) patients during staged palliation and if HLHS patients differ from the rest. Methods: We analyzed SV patients who had a combined cath with CMR at both the preBCPC and preFontan studies from 2016-2019. Flow contrast mapping used to calculate pulmonary arterial (Qpa) and venous (Qpv) flow. Systemic blood flow (Qs) calculated using [superior vena cava (SVC) flow + descending aortic flow at the level diaphragm]. Cerebral vascular resistance (CVRi) calculated using [ascending aortic pressure (AoP)-right atrial pressure (RAP)/SVC flow]. Systemic vascular resistance (SVR) calculated using [(AoP-RaP)/Qs]. Pulmonary vascular resistance (PVR) was calculated using [(mean PAP - LAP)/Qpv]. Results: 30 patients were found, 10 with HLHS. The BCPC unloaded the heart, EDVi fell from preBCPC to preFontan. From preBCPC to preFontan(Table1): PA flow fell, but was compensated by increased APC flow to keep QpQs~1, PApressure and PVRi fell. Compared to others, the HLHS patients had larger hearts (EDVi) and lower PA but higher APC flow at both preBCPC(Table2)and preFontan(Table3). By preFontan, HLHS patients had worse function: higher ESVi, lower EF. Conclusion: QpQs ~1 is maintained by increase in APC flow. HLHS hearts are larger and deteriorate progressively.

Loss of Ventricular Function After Bidirectional Cavopulmonary Connection: Who Is at Risk?

Decline of single ventricle systolic function after bidirectional cavopulmonary connection (BDCPC) is thought to be a transient phenomenon. We analyzed ventricular function after BDCPC according to ventricular morphology and correlated this evolution to long-term prognosis. A review from Mayo Clinic databases was performed. Visually estimated ejection fraction (EF) was reported from pre-BDCPC to pre-Fontan procedure. The last cardiovascular update was collected to assess long-term prognosis. A freedom from major cardiac event survival curve and a risk factor analysis were performed. 92 patients were included; 52 had left ventricle (LV) morphology and 40 had right ventricle (RV) morphology (28/40 had hypoplastic left heart syndrome (HLHS)). There were no significant differences in groups regarding BDCPC procedure or immediate post-operative outcome. EF showed a significant and relevant decrease from baseline to discharge in the HLHS group: 59 ± 4% to 49 ± 7% or − 9% (p < 0.01) vs. 58 ± 3% to 54 ± 6% or − 4% in the non-HLHS RV group (p = 0.04) and 61 ± 4% to 60 ± 4% or − 1% in the LV group (p = 0.14). Long-term recovery was the least in the HLHS group: EF prior to Fontan 54 ± 2% vs. 56 ± 6% and 60 ± 4%, respectively (p < 0.01). With a median follow-up of 8 years post-BDCPC, six patients had Fontan circulation failure, four died, and three had heart transplantation. EF less than 50% at hospital discharge after BDCPC was strongly correlated to these major cardiac events (HR 3.89; 95% Cl 1.04–14.52). Patients with HLHS are at great risk of ventricular dysfunction after BDCPC. This is not a transient phenomenon and contributes to worse prognosis.

The comparative role of echocardiography and MRI for identifying critical lesions in patients with single-ventricle physiology, before bidirectional cavopulmonary connection

BackgroundIn the era of multi-modality imaging, this study compared contemporary, pre-operative echocardiography and cardiac MRI in predicting the need for intervention on additional lesions before surgical bidirectional cavopulmonary connection.MethodsA total of 72 patients undergoing bidirectional cavopulmonary connection for single-ventricle palliation between 2007 and 2012, who underwent pre-operative assessment using both echocardiography and MRI, were included. The pre-determined outcome measure was any additional surgical or catheter-based intervention within 6 months of bidirectional cavopulmonary connection. Indices assessed were as follows: indexed dimensions of right and left pulmonary arteries, coarctation of the aorta, adequacy of interatrial communication, and degree of atrioventricular valve regurgitation.ResultsMedian age at bidirectional cavopulmonary connection was 160 days (interquartile range 121–284). The following MRI parameters predicted intervention: Z score for right pulmonary artery (odds ratio 1.77 (95% confidence interval 1.12–2.79, p=0.014)) and left pulmonary artery dimensions (odds ratio 1.45 (1.04–2.00, p=0.027)) and left pulmonary artery report conclusion (odds ratio 1.57 (1.06–2.33)). The magnetic resonance report predicted aortic arch intervention (odds ratio 11.5 (3.5–37.7, p=0.00006)). The need for atrioventricular valve repair was associated only with magnetic resonance regurgitation fraction score (odds ratio 22.4 (1.7–295.1, p=0.018)). Echocardiography assessment was superior to MRI for predicting intervention on interatrial septum (odds ratio 27.7 (6.3–121.6, p=0.00001)).ConclusionFor branch pulmonary arteries, aortic arch, and atrioventricular valve regurgitation, MRI parameters more reliably predict the need for intervention; however, echocardiography more accurately identified the adequacy of interatrial communication. Approaching bidirectional cavopulmonary connection, the diagnostic strengths of MRI and echocardiography should be acknowledged when considering intervention.