Increasing age and atrial arrhythmias are associated with increased thromboembolic events in a young cohort of adults with repaired tetralogy of Fallot

Background Adults with repaired Tetralogy of Fallot (rTOF) comprise one of the largest cohorts among adults with congenital heart disease (ACHD). These patients have a higher burden of atrial arrhythmias (AA), leading to increased adverse events, including stroke and transient ischemic attack (TIA). However, the data on factors associated with stroke/TIA in rTOF are limited, and classic risk factors may not apply. We studied event rates and associated factors for thromboembolism in a rTOF cohort. Methods Retrospective cohort study of all adult patients age >18 years with rTOF followed at a single ACHD tertiary care center. AA of interest were atrial fibrillation (AF) and atrial flutter (AFL). Results Data from 260 patients were identified, mean age 37.6 SD 13.3 years, followed over 5108 patient-years (mean 16.6 SD 8.2 years). 43 patients had AF and/or AFL, and 30 patients had thromboembolic events, of which 19 patients had stroke/TIA. The event rate for any thromboembolism was 3.39 per 100 patient-years follow-up in patients with AA, compared to 1.80 in patients without (P = .07). In univariate analysis, older age and diabetes were associated with thromboembolic events. In multivariate analysis, only older age was associated with thromboembolic events. Conclusions In our relatively young cohort of adults with rTOF, there was a high prevalence of AA, associated with nearly double the rate of thromboembolic events compared to patients without AA. Older age alone is independently associated with thromboembolic events. Further studies into assessment of silent AA are required, and routine assessments should be considered at an earlier age.