Frequent atrial extrasystolic beats predict atrial fibrillation in patients with congenital heart defects

Atrial fibrillation (AF) is increasingly observed in patients with congenital heart defects (CHDs) who survive nowadays into adulthood. Yet, predictors of AF are scarce in this high-risk population. This study therefore examined the predictive ability of atrial extrasystole (AES) for development of AF in CHD patients.

Adult CHD patients who had a 24 h Holter registration were followed to determine who developed AF. A total of 573 patients (49% male, mean age 35 ± 12 years) were included; they had a simple/complete repaired CHD (n = 279), complex repaired CHD (n = 251), or univentricular heart (UVH, n = 43). Ageing (P < 0.0001), female gender (P = 0.028), UVH (P = 0.0010), and left atrial dilatation (P = 0.0025) were associated with the number of AES. During a median follow-up of 51.6 months (interquartile range 22.8–85.7), 29 patients (5%) developed de novo AF. An one-point increase in the number of _logtotal-AES was associated with a two-fold higher risk of AF development (hazard ratio 1.95; 95% confidence interval 1.21–3.13; P = 0.016). C-statistic for left atrial dilatation, complexity, and age had a good discriminative ability for the incidence of AF with a C-statistic of 84.5%. The addition of the total number of AES/24 h to this model increased C-statistic to 88.4%.

Atrial extrasystole occur relatively frequent in adult CHD patients compared with patients with other cardiac diseases. This is the first study that showed an association between an increased AES frequency and a higher risk of AF development in CHD patients.