Citations

Background Patients with single-ventricle physiology are often palliated with the Fontan operation, which may involve the creation of a fenestration. We aimed to evaluate differences in cardiopulmonary exercise test (CPET) performance between patients with fenestrated and non-fenestrated Fontan circulation. Methods Patients with a Fontan circulation referred to CPET between 2006 and 2024 were included and were categorised based on their fenestration status at the time of CPET. Logistic regression analyses were performed to assess the impact of fenestration on peak oxygen consumption (VO 2 ), and Cox proportional hazard to evaluate the impact of fenestration on cardiovascular outcomes (death, heart transplant and Fontan-related hospitalisation). Results Of the 184 patients, 141 were classified as non-fenestrated and 43 as fenestrated. The minute ventilation-carbon dioxide production (V E /VCO 2 slope) was higher in the fenestrated (36.9±7.9) versus (33.2±6.2; p=0.009) in the non-fenestrated group. There was no significant difference in predicted VO 2 between groups (non-fenestrated 51.9%±14.4 vs 51.3%±15.6; p=0.7). Resting oxygen saturation was higher in the non-fenestrated group (93%±4.7 compared with fenestrated group 90.1%±5; p<0.001). Fontan fenestration was not significantly associated with the composite outcome; older patient age at the time of the CPET, cirrhosis and ventricular ejection fraction <40% were significantly associated with higher risk, while higher resting systolic blood pressure, left ventricular morphology and higher predicted peak VO 2 were protective. Conclusions The increased hypoxia and reduced ventilatory efficiency associated with Fontan fenestration offset any potential benefits, resulting in similar exercise performance between the groups. Fontan fenestration was not significantly associated with cardiovascular outcomes.

Aortic dilation following single ventricle palliation is increasingly recognized, although its long-term clinical implications remain unclear. We present the case of a 38-year-old male born with a bicuspid aortic valve, d-transposition of the great arteries, ventricular septal defect, right ventricular hypoplasia with a straddling right atrioventricular valve. He was palliated with Fontan circulation and developed severe neo-aortic root and arch dilation with native aortic valve stenosis, requiring surgical intervention. His neo-aortic root measured 81 × 65 mm, necessitating a Bentall procedure with total arch and native aortic valve replacement. This case underscores the variable progression of aortic dilation in patients with palliated single ventricle physiology and the need for strict surveillance and individualized management. Larger cohort studies are needed to further refine the criteria for surgical intervention in this unique population.

We present a case study of neotricuspidization of the aortic valve with neocusp suturing based on templates similar to those used in the Ozaki procedure but adapted for infants. This is an alternative for patients when valve reconstruction is impossible or risky. A good postoperative hemodynamic outcome was obtained, but it is necessary to evaluate this approach on the basis of long-term results.

Background: Many children born with single ventricle physiology are palliated with Fontan operation, which may include a fenestration creation. This has been demonstrated to improve short-term outcomes after surgery. Reduced exercise capacity has been shown to be a predictor of prognosis in Fontan patients. Aim: We sought to compare cardiopulmonary exercise test (CPET) data between fenestrated and non-fenestrated Fontan patients. Methods: We conducted a retrospective cohort study of 185 patients referred for CPET from 2011 to 2024. Patients with complete CPET data were included. Type of Fontan, comorbidities, and echocardiogram data were ascertained electronically. Patients were divided into 2 different groups according to the fenestration patency. Fisher’s exact test or chi-square was used to compare categorical variables. T-test and Turkey-Kramer were used to compare continuous variables. Adjustment using General Lineal Models procedure were used to identify any confounder that could affect the results. P value <0.05 was considered significant. Results: 142 patients were classified in the non-fenestrated (NF) group, and 43 in the fenestrated group (FF). Baseline characteristics of both groups are shown in Table 1. From the evaluated CPET variables, the minute ventilation-carbon dioxide production (VE/VCO2) was higher in the FF (p=<0.001), and oxygen saturation at peak exercise (SatO2) was lower in this group (p= <0.001) (Figure 1). There was no significant difference between peak oxygen consumption (VO2) between groups. When adjusted by comorbidities only VE/VCO2 nadir, slope and peak SatO2 were statistically significant different between groups (Table 2). Conclusion: Ventilatory variables showed significant differences when fenestration was presented, secondary to V-Q mismatch from increased right to left shunt. Despite the theoretical advantage of increased cardiac output from Fontan fenestration, exercise performance was similar between both groups.

Cardiac ventricular pressure overload affects patients with congenital heart defects and can cause cardiac insufficiency. Grafts of stem cell–derived cardiomyocytes are proposed as a complementary treatment to surgical repair of the cardiac defect, aiming to support ventricular function. Here, we report successful engraftment of human induced pluripotent stem cell–derived cardiac lineage cells into the heart of immunosuppressed rhesus macaques with a novel surgical model of right ventricular pressure overload. The human troponin+ grafts were detected in low-dose (2 × 10 6 cells/kg) and high-dose (10 × 10 6 cells/kg) treatment groups up to 12 weeks post-injection. Transplanted cells integrated and progressively matched the organization of the surrounding host myocardium. Ventricular tachycardia occurred in five out of 16 animals receiving cells, with episodes of incessant tachycardia observed in two animals; ventricular tachycardia events resolved within 19 days. Our results demonstrate that grafted cardiomyocytes mature and integrate into the myocardium of nonhuman primates modeling right ventricular pressure overload.

This clinical case series describes the surgical management of tetralogy of Fallot in five children using autologous right atrial appendage to reconstruct the right ventricular outflow tract. Transthoracic echocardiography performed at four-year follow-up showed a mild residual gradient and moderate regurgitation of the neopulmonary valve in all cases.

Background Quadricuspid aortic valve (QAV) is an exceedingly rare congenital heart defect (CHD) which has not been well-defined in a pediatric population. Methods The Mayo Clinic echocardiography database was retrospectively analyzed to identify patients ≤18 years diagnosed with QAV from January 1990 to December 2023. Patients with truncus arteriosus were excluded. All images were independently reviewed to define morphology of the QAV by using the Hurwitz and Roberts classification. Results Fourteen patients with QAV were identified with a median age at time of diagnosis being 10.5 years (interquartile range [IQR] 6-14 years). Male-to-female ratio was 3:1. Associated CHDs were present in 50% (n = 7) patients. The most common morphological subtypes of QAV were Type D in 43% (n = 6) and Type B in 29% (n = 4). Aortic regurgitation was the most frequently associated valvular abnormality affecting 86% (n = 12) cases, with greater than moderate regurgitation in only two patients. Aortic valve stenosis was observed in 14% (n = 2) patients. Ascending aortic dilatation was present in 21% (3/14) of the cohort, but only 14% (1/7) of isolated QAV patients. At a mean follow up of 11 ± 6.6 years and a median follow-up age of 22 years (IQR 14-27 years), survival was 100% with no primary interventions on the aortic valve or aorta. However, four patients required surgical interventions for associated CHDs. Conclusion Among children with QAV, almost half of the patients had additional CHD. Aortic regurgitation was the predominant hemodynamic abnormality. Long-term survival was excellent with minimal progression during childhood and adolescence.

Background: Patients (pts) with protein losing enteropathy (PLE) following the Fontan operation (op) have a reported 50% mortality at 5 years (yrs) post diagnosis. We review our clinical outcomes in this pt population. Methods: From 1997 to 2010, 42 pts (55% M) with PLE following the Fontan op were identified from clinical databases. Data were collected by retrospective chart review. Results: Mean age at PLE diagnosis was 18.9 yrs + 11 (4.7-57.9 yrs) and initial Fontan op was 10.1 yrs + 10.8 (1.8-37.6 yrs). Mean time from Fontan op to PLE diagnosis was 8.4 yrs + 14.2 (30 days-27yrs). Types of Fontan op included: atriopulmonary connection (28, 67%), lateral tunnel or intraatrial conduit (6, 14%), or extracardiac conduit (8, 19%). Mean time from diagnosis to last follow-up was 8 yrs + 6 (1-22yrs). Survival was 88% at 5 yrs. There were 11 deaths, mean age 32 yrs + 7.7 (22-47 yrs). Mean time interval from diagnosis to death was 7.5 yrs + 5.4 (1-18yrs). Causes of death include: sepsis (7), complications after Fontan conversion (1), and unknown (3). Decreased survival was seen in pts with high Fontan pressure (mean >15mmHg, p=0.04), decreased ventricular function (EF < 55%, p=0.03), and NYHA class >2 at diagnosis (p=0.04). Pts who died had higher pulmonary vascular resistance (3.8 + 1.6 WU vs 2.1 + 1.1 WU, p=0.017), lower cardiac index (1.6 L/min/m 2 + 0.4 vs 2.7 L/min/m 2 + 0.7, p<0.0001), and lower mixed venous saturation (53% versus 66%, p=0.01) compared to survivors. All factors were obtained at initial PLE diagnosis. Pts treated with medical therapy only (n=15) resulted in symptomatic improvement in 7 pts (47%), no improvement in 5 (33%), and death in 3 (20%). Pts treated with medical + surgical/interventional catheterization procedures (n=27) resulted in symptomatic improvement in 10 pts (37%), no improvement in 9 (33%), and death in 8 (30%). Treatments used more in survivors included spironolactone (21, 68%), octreotide (7, 21%), sildenafil (6, 19%), fenestration creation (15, 48%), and relief of Fontan obstruction (7, 23%). Of the 31 survivors, 17 pts remain well-controlled. Conclusions: PLE remains difficult to treat, but in the current era, survival has improved with advances in treatment. Further study is needed to understand the mechanism of disease and ideal treatment strategy.

Anomalous origin of the left coronary artery from the pulmonary artery (ALCAPA) is a rare coronary anomaly that can present in childhood or adulthood with a multitude of symptoms depending on the age of presentation. It should be suspected in infants presenting with heart failure in the setting of left ventricular systolic dysfunction and associated mitral regurgitation from papillary muscle ischemia. Adults with ALCAPA may present with cardiac ischemic symptoms. Prompt diagnosis with echocardiography and cross-sectional chest imaging is important to guide surgical intervention and improve the patients’ survival and prognosis. The goal of surgery is to establish a dual-coronary system with mid-term results revealing progressive recovery of left ventricular function and improvement in mitral regurgitation. Patients with ALCAPA should maintain life-long follow-up with a cardiologist with congenital heart disease expertise for surveillance of post-operative complications.