Anticoagulation and incidence of late cerebrovascular accidents following the Fontan procedure

Thromboembolic events are a well-reported complication following the Fontan procedure, but no previous studies have compared the incidence of thromboembolic events relative to the prophylactic anticoagulation strategy utilized. We examined the time-adjusted incidence of late thromboembolic events relative to chronic anticoagulation strategy. All patients who have undergone Fontan palliation and are followed at our institution were reviewed. All thromboembolic and major bleeding events were recorded and compared among different subgroups (anticoagulant medication utilized, Fontan variant, and the presence of a residual right-to-left shunt). The incidence of late cerebrovascular accidents (CVAs) per patient-year was calculated for each subgroup. The records of 132 patients were analyzed (median follow-up, 7.6 years; 1066.5 total patient-years). There were no major bleeding complications. One patient receiving no anticoagulation therapy developed a symptomatic thrombus 6 months after Fontan. Three patients suffered late CVAs (range, 3-7 years); 2 were receiving aspirin, and the other received no anticoagulation therapy. All 3 had lateral tunnel Fontan and a residual right-to-left shunt. The overall incidence of late CVA was 2.3%, with an event rate of 0.28% per patient-year. Late CVA was not related to anticoagulation strategy or time from Fontan procedure but was associated with a residual right-to-left shunt and lateral tunnel-type Fontan palliation (p < 0.001). Regardless of anticoagulation strategy utilized, symptomatic CVA is a rare long-term complication following the Fontan procedure.