Efficacy of heart transplantation in patients with a failing Fontan: a systematic review and meta-analysis

Heart Transplantation Outcomes for Fontan Patients When Using Contemporary Strategies: Heart-Liver Transplantation and Ventricular Assist Device Therapy

BACKGROUND

With an increasing number of Fontan patients surviving into adulthood, the burden of end-stage heart failure is increasing. Prior studies have reported suboptimal heart transplantation (HTx) outcomes. Therefore, the authors describe their institutional experience of HTx in patients with Fontan circulation failure, including en-bloc heart-liver transplantation (HLTx) and pretransplant systemic ventricular assist device (SVAD) therapies.

METHODS

All consecutive Fontan-palliated patients undergoing HTx or HLTx between 2013 and 2022 at the authors' institution were included. Pretransplant characteristics and posttransplant outcomes were recorded.

RESULTS

Twenty-six transplant recipients, including 5 (19%) HLTx recipients, were identified. The majority (n = 16, 62%) of patients had a cardiac diagnosis of hypoplastic left heart syndrome. Seven (26%) patients were bridged to transplant on an SVAD; the median duration of support was 104 [IQR 39-543] days. Transplantation occurred at a median of 10.6 [IQR 6.8-15.6] years post-Fontan. Fourteen (54%) patients had ≥1 in-hospital complication and 4 (15%) patients required an in-hospital reoperation. Postdischarge reinterventions included tricuspid valve repair (n = 1, 4%) and retransplantation (n = 1, 4%). Two (8%) in-hospital mortalities [22 days (post-HLTx), 2.9 months (post-HTx] and 4 (15%) postdischarge mortalities [5.4 months, 3.1 years, 5.7 years, 7.1 years (all post-HTx)] occurred. Overall survival was excellent, with in-hospital, one-year, and five-year actuarial survival being 92%, 89%, and 80%, respectively.

CONCLUSIONS

The current series demonstrates that excellent posttransplant outcomes are achievable for patients with Fontan circulation failure using a comprehensive approach including SVAD and HLTx therapies. Pretransplant optimization, sometimes including SVAD implantation, and meticulous operative planning are imperative strategies for successful patient outcomes.

Optimizing Referral Timing of Patients With Fontan Circulatory Failure for Heart Transplant

BACKGROUND

There are no criteria guiding the timing of heart transplant referral for Fontan patients, nor are there any characteristics of those deferred or declined listing reported. This study examines comprehensive transplant evaluations for Fontan patients of all ages, listing decisions, and outcomes to inform referral practices.

METHODS

Retrospective review of 63 Fontan patients formally assessed by the advanced heart failure service and presented at Mayo Clinic transplant selection committee meetings (TSM) January 2006 to April 2021. The study is compliant with the Helsinki Congress and Declaration of Istanbul and included no prisoners. Statistical analysis was performed with Wilcoxon Rank Sum and Fisher's Exact tests.

RESULTS

Median age at TSM was 26 years (17.5, 36.5). Most were approved (38/63 [60%]); 9 of 63 (14%) were deferred and 16 of 63 (25%) were declined. Approved patients more commonly were <18 years old at TSM (15/38 [40%] vs 1/25 [4%], P = .002) compared with those deferred/declined. Complications of Fontan circulatory failure were less common in approved vs deferred/declined patients: ascites (15/38 [40%] vs 17/25 [68%], P = .039), cirrhosis (16/38 [42%] vs 19/25 [76%], P = .01), and renal insufficiency (6/38 [16%] vs 11/25 [44%], P = .02). Ejection fraction and atrioventricular valve regurgitation did not differ between groups. Pulmonary artery wedge pressure was overall high normal (12 mm Hg [9,16]) but higher in deferred/declined vs approved patients, 14.5 (11, 19) vs 10 (8, 13.5) mm Hg, P = .015. Overall survival was significantly lower in deferred/declined patients (P = .0018).

CONCLUSION

Fontan patient referral for heart transplant at younger age and before the onset of end-organ complications is associated with increased approval for transplant listing.

Heart transplant indications, considerations and outcomes in Fontan patients: Age-related nuances, transplant listing and disease-specific indications

In the current era, 5-10% of Fontan patients die or need a transplant in childhood, and approximately 50% will experience the same fate by age 40 years. Heart transplant (HTx) can be successful for selected children and adults with Fontan circulatory failure (FCF) of any mechanism, with a 1-year post-transplant survival approaching 90% in children and 80% in the largest single-centre adult Fontan HTx experience. Protein losing enteropathy and plastic bronchitis can be expected to resolve post-transplant and limited data suggests patients with FALD who survive HTx can expect improvement in liver health. Early Fontan failure, within 12 months of Fontan completion, is not easily rescued by HTx and late referrals / failure to refer adult patients remains problematic. Very little is known about the numbers of patients not referred, turned down following assessment for HTx, or dying on the waiting list which are needed to understand the complete picture of HTx in the Fontan population and to identify where best to focus quality improvement efforts. Recent revisions to listing prioritization in Canada with considerations specific to the Fontan population aim to mitigate the fact that the status listing criteria are not tailored to the congenital heart population. Transplanting high-risk children prior to Fontan completion, developing ACHD transplant centres of expertise which can also offer combined heart-liver transplant when appropriate, and improving single ventricle mechanical support options and criteria for both adults and children may help mitigate the early post-listing mortality.