Heart transplantation for adults with congenital heart disease: current status and future prospects

Long-term outcomes after heart transplantation in adult patients with univentricular versus biventricular congenital heart disease

OBJECTIVES

Heart transplantation (HT) is the only life-extending therapy in adults with congenital heart disease (CHD) and end-stage heart failure. HT is considered at high risk in complex CHD given the anatomical complexity and past medical history. Little is known about long-term outcomes after HT in these patients. We aimed to evaluate early and long-term outcomes after HT in adult patients with univentricular versus biventricular CHD.

METHODS

This multicentre retrospective cohort study included all adult CHD patients who underwent HT between 1988 and 2021 in 3 tertiary centres. Factors associated with early (<30 days) and conditional long-term survival were assessed in the entire cohort.

RESULTS

Over a mean follow-up of 10.1 ± 7.8 years, 149 patients were included, of whom 55 (36.9%) had univentricular CHD. Sixty-four patients died during follow-up including 47 deaths before discharge from hospital. In multivariable analysis, univentricular physiology and female recipient gender were independently associated with a higher risk of early mortality (odds ratio 2.99; 95% confidence interval [1.33-6.74] and odds ratio 2.76; 95% confidence interval [1.23-6.20], respectively). For patients who survived the early period, conditional long-term survival was excellent for both groups and was not different between 2 groups (P = 0.764).

CONCLUSIONS

Adult CHD patients have a high incidence of overall mortality due to a high rate of early mortality. Univentricular physiology was associated with a significant increased risk of early death compared to biventricular physiology. However, late mortality was excellent and no longer different between the 2 physiologies.

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.

The Role of Serial Right Heart Catheterization Survey in Patients Awaiting Heart Transplant on Ventricular Assist Device

Current guidelines recommend serial right heart catheterization (RHC) to survey pulmonary hypertension in patients awaiting heart transplant. However, the role and impact of this surveillance is unclear in patients with a left ventricular assist device (LVAD). We reviewed our surveillance RHC protocol to determine whether useful data were obtained to justify the risks of serial invasive procedures (i.e., excessive bleeding). Between January 2015 and December 2018, 78 patients who received an LVAD as bridge-to-transplant (BTT) were included in this study. Routine RHC surveillance was performed every 6 months. Hemodynamic variables were retrospectively collected and reviewed. In 78 patients, 205 RHCs were analyzed. Median patient age was 54 years (IQR 46-61), and 64 (82%) were male. Thirty-six patients (46%) had pulmonary vascular resistance (PVR) ≤ 3 Wood units (WUs), and 42 patients (54%) had PVR > 3 WUs before LVAD. After LVAD implantation, mean PVR decreased by 36% from 3.8 ± 2.1 to 2.4 ± 1.1 WUs (p < 0.001) at 6 months and stabilized below 3 WUs at all post-LVAD time points. Four patients (11%) with pre-LVAD PVR ≤ 3 and 16 patients (38%) with a pre-LVAD PVR > 3 had PVR > 3 at least once during RHC survey. Of the 56 (76%) transplanted patients, six (40%) of 15 patients with a post-LVAD PVR >3 at least once developed moderate-to-severe right ventricular dysfunction. Although PVR significantly decreased after LVAD implant, PVR values fluctuated, particularly for those with pre-LVAD PVR > 3.0 WUs. Routine RHC appears valid for all BTT patients.

A Risk Score for Adults With Congenital Heart Disease Undergoing Heart Transplantation

BACKGROUND

This study derived and validated a risk score for 1-year mortality in patients with adult congenital heart disease (ACHD) undergoing orthotopic heart transplantation (OHT).

METHODS

The United Network for Organ Sharing registry identified patients with ACHD (≥18 years of age) who underwent OHT between 1987 and 2018. The primary outcome was 1-year mortality. Associated covariates (univariate P < .2) were entered into a multivariable logistic regression model. Variable inclusion in the model was assessed by improvement in the McFadden pseudo-R², likelihood ratio test, and C-index. A risk score was created using the absolute magnitude of the odds ratios from the derivation cohort, and its ability to predict 1-year mortality was tested in the validation cohort.

RESULTS

A total of 1388 recipients were randomly divided into derivation (66.7%, n = 950) and validation (33.3%, n = 438) cohorts. A 13-point risk score incorporating 4 pretransplant variables (age, dialysis dependence, serum bilirubin level, and mechanical ventilation) was created. The predicted 1-year mortality ranged from 14.6% (0 points) to 49.9% (13 points) (P < .001). In weighted regression analysis, there was a strong correlation between predicted 1-year mortality and observed 1-year mortality in the validation cohort (r = 0.85, P < .001). Logistic regression also demonstrated a significant association (odds ratio, 1.18; 95% confidence interval, 1.1-1.3; P = .004). The Brier score of the composite score in the validation cohort was 0.14. Kaplan-Meier analysis demonstrated that risk scores of 4 points or higher portended worse survival at 1-year posttransplant (P < .001).

CONCLUSIONS

This 13-point risk score for ACHD is predictive of mortality within 1 year after OHT and has potential utilization in improving recipient selection for OHT in adult patients with CHD.

Budesonide for Protein Losing Enteropathy in Patients with Fontan Circulation: A Systematic Review and Meta-Analysis

Background:

Recent studies have shown that oral budesonide can be used to improve albumin level in patients with protein-losing enteropathy (PLE) following Fontan procedure. However, there has never been a systematic review and meta-analysis to confirm this finding. We performed a systematic review and meta-analysis to explore the therapeutic effect of budesonide in patients with PLE post-Fontan procedure.

Methods:

We searched the databases of MEDLINE and EMBASE from inception to January 2019. Included studies were published studies that evaluate albumin level before and after budesonide therapy in patients with PLE following Fontan procedure. Data from each study were combined using the random-effects model.

Results:

Five studies with 36 post-Fontan operation patients with PLE were included. In random-effects model, there was a statistically significant difference in albumin level between before and after budesonide treatment (weighted mean difference = 1.28, 95% confidence interval: 0.76-1.79). No publication bias was observed on a funnel plot and Egger test with a P value of .676.

Conclusions:

The results of this systematic review and meta-analysis show that budesonide can be used to increase albumin level in patients with PLE following Fontan operation. Further studies may focus on the impact of outcome of budesonide in this population.

Short-term outcomes of en bloc combined heart and liver transplantation in the failing Fontan

Patients with failing Fontan physiology and liver cirrhosis are being considered for combined heart and liver transplantation. We performed a retrospective review of our experience with en bloc combined heart and liver transplantation in Fontan patients > 10 years old from 2006 to 18 per Institutional Review Board approval. Six females and 3 males (median age 20.7, range 14.2-41.3 years) underwent en bloc combined heart and liver transplantation. Indications for heart transplant included ventricular dysfunction, atrioventricular valve regurgitation, arrhythmia, and/or lymphatic abnormalities. Indication for liver transplant included portal hypertension and cirrhosis. Median Fontan/single ventricular end-diastolic pressure was 18/12 mm Hg, respectively. Median Model for End-Stage Liver Disease excluding International Normalized Ratio score was 10 (7-26), eight patients had a varices, ascites, splenomegaly, thrombocytopenia score of ≥ 2, and all patients had cirrhosis. Median cardiopulmonary bypass and donor ischemic times were 262 (178-307) and 287 (227-396) minutes, respectively. Median intensive care and hospital stay were 19 (5-96) and 29 (13-197) days, respectively. Survival was 100%, and rejection was 0% at 30 days and 1 year post-transplant. En bloc combined heart and liver transplantation is an acceptable treatment in the failing Fontan patient with liver cirrhosis.

Current spectrum, challenges and new developments in the surgical care of adults with congenital heart disease

Today, more than two thirds of patients with congenital heart disease (CHD) are adults. Cardiac surgery plays an essential role in restoring and maintaining cardiac function, aside from evolving medical treatment and catheter-based interventions. The aim of the present publication was to describe the spectrum of operations performed on adults with CHD (ACHD) by reviewing current literature. Currently, surgery for ACHD is predominantly valve surgery, since valvular pathologies are often either a part of the basic heart defect or develop as sequelae of corrective or palliative surgery. Surgical techniques for valve repair, established in patients with acquired heart disease (non-ACHD), can often be transferred to ACHD. New valve substitutes may help to reduce the number of redo operations. Most of valve operations yield good results in terms of survival and quality of life, with the precondition that the ventricular function is preserved. Heart failure due to end-stage CHD is the most frequent cause of mortality in ACHD. However, surgical treatment by means of mechanical circulatory support (MCS) is still uncommon and the mortality exceeds the one following other operations in ACHD. Currently, different devices are used and new technical developments are in progress. However, there still is no ideal assist device available. Therefore, heart transplantation remains the only valid option for end-stage CHD. Despite higher early mortality following heart transplantation in ACHD compared to non-ACHD, the long-term survival compares favorably to non-ACHD. There is room for improvement by refining the indications, the time of listing, and the perioperative care of ACHD transplant patients. Sudden death is the second most frequent cause of mortality in ACHD. Ventricular tachycardia is the most frequent cause of sudden death followed by coronary artery anomaly. Due to the increasing awareness of physicians and the improved imaging techniques, coronary artery anomalies are coming more into the focus of cardiac surgeons. However, the reported experience is limited and it is currently difficult to provide a standardized and generally applicable recommendation for the indication and the adequate surgical technique. With the increasing age and complexity of ACHD, treatment of rhythm disturbances by surgical ablation, pacemaker or implantable cardioverter defibrillator (ICD) implantation and resynchronisation gains importance. A risk score specifically designed for surgery in ACHD is among the newest developments in predicting the outcome of surgical treatment of ACHD. This evidence-based score, derived from and validated with data from the Society of Thoracic Surgeons Congenital Heart Surgery Database, enables comparison of risk-adjusted performance of the whole spectrum of procedures performed in ACHD and helps in understanding the differences in surgical outcomes. The score is thus a powerful tool for quality control and quality improvement. In conclusion, new developments in surgery for ACHD are currently made with regard to valve surgery, which comprises more than half of all operations in ACHD and in treatment of end-stage CHD, which still yields high mortality and morbidity.

Noteworthy Literature published in 2017 for Congenital Cardiac Anesthesiologists

This review focuses on the literature published during the 13 months from December 2016 to December 2017 that is of interest to anesthesiologists taking care of children and adults with congenital heart disease. Five themes are addressed during this time period and 100 peer-reviewed articles are discussed.

Overview of adult congenital heart transplants

Transplantation for adult patients with congenital heart disease (ACHD) is a growing clinical endeavor in the transplant community. Understanding the results and defining potential high-risk patient subsets will allow optimization of patient outcomes. This review summarizes the scope of ACHD transplantation, the mechanisms of late ventricular dysfunction, the ACHD population at risk of developing heart failure, the indications and potential contraindications for transplant, surgical considerations, and post-transplant outcomes. The findings reveal that 3.3% of adult heart transplants occur in ACHD patients. The potential mechanisms for the development of late ventricular dysfunction include a morphologic systemic right ventricle, altered coronary perfusion, and ventricular noncompaction. The indications for transplant in ACHD patients include systemic ventricular failure refractory medical therapy, Fontan patients failing from chronic passive pulmonary circulation, and progressive cyanosis leading to functional decline. Transplantation in ACHD patients can be quite complex and may require extensive reconstruction of the branch pulmonary arteries, systemic veins, or the aorta. Vasoplegia, bleeding, and graft right ventricular dysfunction can complicate the immediate post-transplant period. The post-transplant operative mortality ranges between 14% and 39%. The majority of early mortality occurs in ACHD patients with univentricular congenital heart disease. However, there has been improvement in operative survival in more contemporary studies. In conclusion, the experience with cardiac transplantation for ACHD patients with end-stage heart failure is growing, and high-risk patient subsets have been defined. Significant strides have been made in developing evidence-based guidelines of indications for transplant, and the intraoperative management of complex reconstruction has evolved. With proper patient selection, more aggressive use of mechanical circulatory support, and earlier referral of patients with failing Fontan physiology, outcomes should continue to improve.

Where Is the "Optimal" Fontan Hemodynamics?

Fontan circulation is generally characterized by high central venous pressure, low cardiac output, and slightly low arterial oxygen saturation, and it is quite different from normal biventricular physiology. Therefore, when a patient with congenital heart disease is selected as a candidate for this type of circulation, the ultimate goals of therapy consist of 2 components. One is a smooth adjustment to the new circulation, and the other is long-term circulatory stabilization after adjustment. When either of these goals is not achieved, the patient is categorized as having "failed" Fontan circulation, and the prognosis is dismal. For the first goal of smooth adjustment, a lot of effort has been made to establish criteria for patient selection and intensive management immediately after the Fontan operation. For the second goal of long-term circulatory stabilization, there is limited evidence of successful strategies for long-term hemodynamic stabilization. Furthermore, there have been no data on optimal hemodynamics in Fontan circulation that could be used as a reference for patient management. Although small clinical trials and case reports are available, the results cannot be generalized to the majority of Fontan survivors. We recently reported the clinical and hemodynamic characteristics of early and late failing Fontan survivors and their association with all-cause mortality. This knowledge could provide insight into the complex Fontan pathophysiology and might help establish a management strategy for long-term hemodynamic stabilization.