A 20-Year Follow-up after the Fontan Operation in a Population with Hypoplastic Left Heart Syndrome

Abstract

Background: Thromboembolic events are a cause of significant morbidity and mortality in the Fontan popula-tion. We previously reported on coagulation profile changes in a cohort of patients with hypoplastic left heart syndrome (HLHS) from Stage I through Fontan completion. In this report, we examine their clinical status, antic-oagulation and incidence of thromboembolic events up to 20 years post Fontan. Methods: A retrospective chart review was conducted for twenty (20) surviving patients, from 1998 through December 2020. Patients who underwent orthotopic heart transplantation (OTx) were followed until their transplant. Patients who were found in the original study to have a factor VIII activity level >160%, were examined separately. Results: Most patients had follow-up within the last two years (2018–2020). Two patients underwent OTx and two patients died. Anticoa-gulation strategy was variable. Most patients were on aspirin monotherapy. There was a total of twelve thrombotic events (63.2%). These included six cerebrovascular accidents (two of which were fatal). Three out of the seven patients with elevated factor VIII activity from the original study had thromboembolic events (42.9%). Fontan complications were variable. Some degree of Fontan Associated Liver Disease was universal. Conclusions: This retrospective review of a group of single-ventricle patients post Fontan, illustrates the variability in anticoagula-tion therapy that exists in this population. A large proportion of patients suffered a significant thromboembolic event, including the patients with elevated factor VIII. Further investigation into the patients with elevated factor VIII may help determine whether a different antithrombotic strategy post Fontan would be beneficial.