Ischemic Stroke in Patients With Congenital Heart Disease and Atrial Fibrillation

Background: Atrial fibrillation (AF) is a common arrhythmia in patients with congenital heart disease (CHD), but little is known about the risk for ischemic stroke among younger patients with CHD (aged <65 years) with AF. Methods and Results: Using data from the National Swedish Patient Register and Cause of Death Register, we identified all patients with both CHD and AF born in Sweden between 1970 and 2017. The Swedish total population register was used to identify age- and sex-matched patients without CHD; those with AF were used as controls. Bottos hierarchical classification was used to define CHD as either complex or noncomplex. Controls were followed from the onset of AF until the index ischemic stroke, death, or end of study (December 31, 2017). We identified 951 patients with CHD with AF and 606 controls with AF. Among patients with both CHD and AF, 2.9% of patients (n=28) developed ischemic stroke, compared with 0.5% (n=3) in controls. When adjusted for age, sex, hypertension, and heart failure, a hazard ratio (HR) of 5.16 (95% CI, 1.52-17.46) was acquired. The HR in noncomplex CHD was 3.84 (95% CI, 1.07-13.84), and the HR in complex CHD was 8.34 (95% CI, 2.27-30.57). For patients born in 1970 to 1989, the HR in ischemic stroke was 7.35 (95% CI, 1.70-31.75). No adjusted HR for patients with CHD born in 1990 to 2017 could be acquired due to few events. Conclusions: The risk for ischemic stroke may be 5 times higher in patients with both CHD and AF compared with patients without CHD with AF. However, larger studies may be needed to confirm/refute these results.