Identifying high risk in adults with congenital heart disease and atrial arrhythmias.

Atrial arrhythmias are associated with an increased mortality risk in adults with congenital heart disease (CHD). However, little is known about risk stratification in the specific group of adult patients with CHD and atrial arrhythmias. We sought to identify predictors of mortality in adult with CHD and atrial arrhythmias and to establish a risk score. The study involved 378 adult patients with CHD (mean age 39 ± 13 years) and atrial arrhythmias who had serial follow-up in a tertiary referral center from 1999 through 2009. During a median follow-up of 5.2 years, there were 40 deaths (11%). Overall mortality rate was 2.0% per patient-year. Common modes of death included heart failure-related death (35%), sudden cardiac death (20%), and perioperative death (18%). Independent predictors of mortality were poor functional class (hazard ratio 3.69, 95% confidence interval [CI] 1.69 to 8.03, p = 0.001), single-ventricle physiology (hazard ratio 3.33, 95% CI 1.51 to 7.35, p = 0.003), pulmonary hypertension (hazard ratio 2.96, 95% CI 1.41 to 6.19, p = 0.004), and valvular heart disease (hazard ratio 2.73, 95% CI 1.33 to 5.59, p = 0.006). A risk score was constructed using these predictors in which patients were assigned 1 point for the presence of each risk factor. Mortality rates in the low-risk (no risk factor), moderate-risk (1 risk factor), and high-risk (>1 risk factor) groups were 0.5%, 1.9%, and 6.5% per patient-year, respectively (log-rank p <0.001). In conclusion, in adult with CHD and atrial arrhythmias specific clinical variables identify patients at high risk for death. Importantly, the absence of any of these risk factors is associated with an excellent survival despite the presence of atrial arrhythmias.