Long‐Term Outcomes of Antithrombotic Treatment in a Cohort of 864 Patients With Fontan Circulation

Background: An effective antithrombotic strategy for patients with univentricular heart is required. We determined the prevalence of antithrombotic treatment and survival in patients with Fontan circulation, with secondary outcomes mortality, cardiovascular disease, acute myocardial infarction, and ischemic stroke. Methods: We retrospectively included patients with univentricular heart born in Sweden between January 1, 1970, and December 31, 2017. Data from the National Patient Register, the Cause of Death Register, and the Prescribed Drug Register were used. Patients who underwent total cavopulmonary connection surgery, resulting in Fontan circulation, were included and divided into groups based on treatment: anticoagulation, antiplatelets, and no antithrombotic therapy. Results: In total, 864 patients (median [interquartile range] 14.4 [3.9–24.9] years follow‐up) were included, 511 of whom (59%) were men. Thirty‐six percent received no antithrombotic treatment, and the mortality rate during the follow‐up was 58%. Among the patients treated with antithrombotic treatment, 75% received antiplatelets, with a 4% mortality rate. The mortality incidence rate was 2.40 (95% CI, 1.49–3.67) for antithrombotic treatment and 49.42 (95% CI, 42.50–57.15) without. The hazard ratio for mortality was 22.32 (95% CI, 14.04–35.48) without antithrombotic treatment. The incidence rate of ischemic stroke was 2.45 (95% CI, 1.52–3.75) with antithrombotic treatment and 2.47 (95% CI, 1.13–4.68) without. The incidence rate of acute myocardial infarction was 0.69 (95% CI, 0.25–1.50) with antithrombotic treatment and 2.76 (95% CI, 1.32–5.07) without treatment. Conclusions: Treatment with antiplatelets was associated with lower mortality compared with no antithrombotic treatment.