Anticoagulation practices in adults with congenital heart disease and atrial arrhythmias in Switzerland

Background: In adults with congenital heart disease (CHD) and atrial arrhythmias, recommendations for thromboprophylaxis are vague and evidence is lacking. We aimed to identify factors thatinfluence decision-making in daily practice.
Methods: From the Swiss Adult Congenital HEart disease Registry (SACHER) we identified 241patients with either atrial fibrillation (Afib) or atrial flutter/intraatrial reentrant tachycardia (Aflut/IART). The mode of anticoagulation was reviewed. Logistic regression models were used to assessfactors that were associated with oral anticoagulation therapy.
Results: Compared with patients with Aflut/IART, patients with Afib were older (51 ± 16.1 vs37 ± 16 years, P < .001) and had a higher CHA₂DS₂-VASc (P < .001) and HAS-BLED scores (P =.005). Patients with Afib were more likely on oral anticoagulation than patients with Aflut/IART(67% vs 43%, P < .001). In a multivariate logistic regression model, age [odds ratio (OR) 1.03 peryear, 95%CI (1.01-1.05), P = .019], atrial fibrillation [OR 2.75, 95%CI (1.30-5.08), P = .007], nonparoxysmal atrial arrhythmias [OR 5.33, 95%CI (2.21-12.85)], CHA2DS2-VASc-Score >1 [OR 2.93,95%CI (1.87-4.61), P < .001], and Fontan palliation [OR 17.5, 95%CI (5.57-54.97), P < .001] wereindependently associated with oral anticoagulation treatment, whereas a HAS-BLED score >1 wasassociated with absence of thromboprophylaxis [OR 0.32, 95%CI (0.17-0.60), P < .001].
Conclusions: In this multicenter study, age, type, and duration of atrial arrhythmias, CHA2DS2-VASc and HAS-BLED scores as well as a Fontan palliation had an impact on the use of thromboprophylaxis in adult CHD patients with atrial arrhythmias. In daily practice, anticoagulationstrategies differ between patients with Afib and those with Aflut/IART. Prospective observationalstudies are necessary to clarify whether this attitude is justified.