A cohort study examining predictors of stroke and bleeding among people with congenital heart disease and atrial fibrillation

Abstract Background Congenital Heart Disease (CHD) is associated with development of atrial fibrillation (AF) at an early age. With increased survival of this cohort into adulthood, the prevalence of concurrent CHD and AF is expected to increase over the next several decades. Little is known about the utility of clinical risk factors or prediction models in determining bleeding or stroke rates in adults with CHD and AF. Purpose This study aims to measure the performance of the CHADSVASC and HASBLED scores in a cohort of people with CHD. The association between traditional stroke and bleeding risk factors, as well as CHD-specific factors, will be quantified. Methods Patients age 18 or older attending one of three centers in the USA were included in this study if they had a history of AF on ECG, holter monitor or device interrogation, in addition to a diagnosis of Tetralogy of Fallot (TOF), Double Outlet Right Ventricle (DORV), or Pulmonary Atresia with Intact Ventricular Septum (PA-IVS). Outcomes were major bleeding event, and stroke rate. Analysis was conducted using cox univariable regression controlling for current age. Receiver operator curve and c-statistics were produced for the CHADSVASC and HASBLED scores respectively. Results 326 people were included in this study, of whom 161 (49.5%) had TOF secondary to Pulmonic Stenosis, 126 (38.8%) had TOF secondary to Pulmonary Atresia, 25 (7.7%) had DORV, and 155 (47.7%) had PA-IVS. 227 people used warfarin (79.4%), 28 (9.8%) used apixaban, 9 (3.1%) used Rivaroxaban, 3 (1%) used Edoxaban, and 5 (1.7%) used Enoxaparin for a period of at least 30 days during the study. 13 (4.5%) people didn’t receive anticoagulation during the study. 26 people had a stroke (8.8%) while 85 people (28.6%) had a major bleeding event. Only the CHADSVASC score was significantly associated with stroke rates (HR 2.103, 95% CI 1.555 to 2.844, p<0.001). Clinical variables, such as subtype of CHD, prior conduit placement or unifocalization were not associated with stroke or major bleeding events. C-statistic for the CHADSVASC score in predicting stroke events was 0.755 (Figure 1). C-statistic for the HASBLED score in predicting major bleeding was 0.442 (Figure 2). Conclusions Among people with CHD and AF, the CHADSVASC score can robustly predict stroke events. Other clinical variables are less valuable in predicting either bleeding or strokes. The HASBLED score likely doesn’t have a role in predicting major bleeding episodes in this cohort.