Systemic ventricle morphology impact on ten-year survival after Fontan surgery

Impact of older age at Fontan completion on mid-term survival

BACKGROUND

The optimum age of Fontan completion remains unknown. Currently, the majority of centers worldwide are performing Fontan completion at 2-4 years of age. In Indonesia, lack of awareness and limited resources probably explain why patients seek treatment at advanced stage. This study aimed to evaluate the impact of older age at Fontan completion on mid-term survival.

RESULTS

A single-center retrospective cohort study was performed on 261 patients who underwent Fontan completion between 2008 and 2019 and survived to discharge. The patients were followed up until April 2020, with a median follow-up period of 3 years (range 0-12 years). The median age was 5 years (range 2-24 years). The survival rates of patients with the age at operation ≤ 6 years and > 6 years were 92.1% and 82.8%, respectively. A subgroup analysis showed that the survival rates for age < 4 years, 4-6 years (reference age), 6-8 years, 8-10 years, 10-18 years, and > 18 years were 85.7%, 94.8%, 85.4%, 78.8%, 85.7%, and 66.7%, respectively. Age at Fontan completion of > 6 years (HR 3.84; p = 0.020) was associated with a lower 12-year survival rate. The age at operation of 8-10 years (HR 6.79; p = 0.022) and > 18 years (HR 15.30; p = 0.006) had the worst survival rates.

CONCLUSIONS

An older age at Fontan completion (> 6 years) significantly reduced mid-term survival rate. The age at Fontan of 8-10 years and > 18 years had higher risk of mid-term death than age of 4-6 years.

Cardiopulmonary Exercise Test Outcomes in Fontan Patients With Right Versus Left Single Ventricle Morphology

Background: Congenital heart defects (CHDs) palliated with Fontan surgery often result in a functional single ventricle that is either a morphologically right or left ventricle, and much less commonly undefined. Given this departure from normal physiology, especially for systemic right ventricle Fontan patients, our study sought to compare cardiopulmonary exercise test (CPET) results of adult patients with single right ventricle (SRV) and single left ventricle (SLV) morphology. Methods: Of 237 Fontan patients from the Ahmanson/UCLA Adult Congenital Heart Disease Center database, 135 patients met the inclusion criteria and were split into 2 groups: SRV (n = 44) and SLV (n = 91). Data were collected on baseline demographics, cardiac history, and CPET results. The 2 groups were compared using unpaired t-test, Mann-Whitney, or Chi-square test. Results: Regarding baseline demographics, SRV patients underwent CPET at a slightly younger age than the SLV group (26.5 ± 6.2 vs 29.6 ± 8.5 years, P = .03). There were no significant differences in CPET parameters (including peak heart rate, oxygen saturation, and maximum VO₂/kg) between the SRV and SLV groups. When evaluated subsequent CPET at 3 to 4 years, there was no difference in CPET peak heart rate, peak oxygen saturation, and maximum VO₂/kg between the 2 groups. Conclusions: This single-center retrospective analysis suggests that dominant single ventricle morphology may not be associated with an appreciable difference in exercise performance in adult survivors with a Fontan palliation.

Failures of the Fontan System in Univentricular Hearts and Mortality Risk in Heart Transplantation: A Systematic Review and Meta-Analysis

The Fontan procedure (FP) is the standard surgical treatment for Univentricular heart diseases. Over time, the Fontan system fails, leading to pathologies such as protein-losing enteropathy (PLE), plastic bronchitis (PB), and heart failure (HF). FP should be considered as a transitional step to the final treatment: heart transplantation (HT). This systematic review and meta-analysis aims to establish the risk of death following HT according to the presence of FP complications. There was a total of 691 transplanted patients in the 18 articles, immediate survival 88% (n = 448), survival from 1 to 5 years of 78% (n = 427) and survival from 5.1 to 10 years of 69% (n = 208), >10 years 61% (n = 109). The relative risk (RR) was 1.12 for PLE (95% confidence interval [CI] = 0.89-1.40, p = 0.34), 1.03 for HF (0.7-1.51, p = 0.88), 0.70 for Arrhythmias (0.39-1.24, p = 0.22), 0.46 for PB (0.08-2.72, p = 0.39), and 5.81 for CKD (1.70-19.88, p = 0.005). In patients with two or more failures, the RR was 1.94 (0.99-3.81, p = 0.05). After FP, the risk of death after HT is associated with CKD and with the presence of two or more failures.

Relationship of Ventricular Morphology and Atrioventricular Valve Function to Long-Term Outcomes Following Fontan Procedures

BACKGROUND

The influence of ventricular morphology on Fontan outcomes is controversial.

OBJECTIVES

This study hypothesized that dysfunction of the single right ventricle (RV) and right atrioventricular valve regurgitation (AVVR) increases over time and adversely impacts late outcomes following a Fontan operation. A single-center retrospective study was performed.

METHODS

From 1985 through 2018, 1,162 patients underwent the Fontan procedure at our center and were included in this study. Transplant and takedown free survival, ventricular, and atrioventricular valve dysfunction after Fontan were analyzed. Death or heart transplantation information was obtained from the National Death Index and the Scientific Registry of Transplant Recipients.

RESULTS

The follow-up rate was 99%. Morphologic RV was present in 58% of patients. Transplant and takedown free survival were 91%, 75%, and 71% at 10 years, 20 years, and 25 years, respectively. Morphologic RV was an independent risk factor for transplant, takedown free survival (hazard ratio: 2.4; p = 0.008). The AVVR, which preceded ventricular dysfunction in most cases, was associated with the development of ventricular dysfunction after Fontan (odds ratio: 4.3; 95% confidence interval: 2.7 to 6.7; p < 0.001). Furthermore, AVVR and ventricular dysfunction progressed over time after Fontan, especially in the RV (AVVR: p < 0.0001, ventricular dysfunction: p < 0.0001).

CONCLUSIONS

Morphologic RV is negatively associated with the long-term survival following the Fontan, possibly due to a tendency toward progressive AVVR and deterioration of the single ventricle function. Additional volume overload caused by AVVR may be one of the main factors accelerating the dysfunction of the single RV, implying that early valve intervention may be warranted.