Prevalence and in-hospital mortality during arrhythmia-related admissions in adults with tetralogy of Fallot.

Background: Although outcomes of arrhythmia diagnosis have been described in ambulatory tetralogy of Fallot (TOF) patients, these have not been studied in hospitalized patients. The purpose of this study was to determine the prevalence and in-hospital mortality due to arrhythmias in TOF patients based on a review of the National Inpatient Sample database.

Methods: Admissions in adult TOF patients (2000-2014) were categorized as arrhythmia-related admission (ARA) or non-arrhythmia-related admission (NRA) based on arrhythmia diagnostic codes.

Results: Of 18,353 admissions, 5071 (27.6%) were ARA. The most common arrhythmias were atrial fibrillation (15.5%), atrial flutter (8.4%) and ventricular tachycardia (8.2%), and the prevalence of overall ARA as well as specific arrhythmia types increased over time. In-hospital mortality for ARA was 5.4%, and decreased over time. Arrhythmia diagnosis was an independent predictor of in-hospital mortality (odds ratio [OR] 1.63, 1.34-2.01, p = 0.001). Similarly, atrial fibrillation (OR 1.49, 1.18-1.89, p = 0.001) and ventricular tachycardia (OR: 2.01, 1.55-2.98, p = 0.001) were independent predictors of in-hospital mortality. Compared to small bed-size hospital, ARA in large hospital bed-size hospital was associated with a lower in-hospital mortality (OR 0.71, 0.53-0.96, p = 0.03).

Conclusion: Atrial fibrillation was the most common arrhythmia in hospitalized TOF patients, and arrhythmia diagnosis (specifically atrial fibrillation and ventricular tachycardia) was an independent predictor of in-hospital mortality, while admission to a large bed-size hospital was associated with a lower risk of in-hospital mortality. Further studies are required to determine if a more proactive approach to arrhythmia management in the ambulatory TOF population will reduce hospitalizations and mortality.