Death and thrombo-embolic risk after ablation of atrial flutter compared with atrial fibrillation: a nationwide cohort study

Aims The aim of this study was to investigate whether there is a similar mortality and thrombo-embolic risk, after an atrial ablation procedure, compared with an atrial fibrillation (AF) procedure. Methods and results Using data from nationwide Danish health registries, we identified patients aged 18–75 years undergoing a first-time atrial flutter or an AF ablation procedure in the period 2000–13. Cox proportional hazards regression was used to calculate hazard ratios (HRs) after 5 years of follow-up, adjusting for concomitant risk factors. A total of 1096 and 2266 patients underwent an ablation for atrial flutter or AF, respectively. Age distribution was similar in the two, but atrial flutter patients had more co-morbidities. During 5 years of follow-up, we observed 38 and 36 deaths in the atrial flutter and AF groups, corresponding to an almost two-fold higher mortality rate among atrial flutter patients [crude HR 1.92, 95% confidence interval (CI) 1.22–3.03]. The higher mortality rate persisted after adjustment for age, sex, diabetes mellitus, and hypertension (adjusted HR 1.68, 95% CI 1.05–2.69). The rate of thrombo-embolic events was similar in the two groups (crude HR 1.34, 95% CI 0.71–2.56; adjusted HR 1.22, 95% CI 0.62–2.41). Conclusion In this observational study, patients with atrial flutter had a significantly higher all-cause mortality rate compared with those with AF after an ablation procedure, but similar thrombo-embolic event rates. Future studies should elucidate the reason for this difference in mortality. [10.1093/europace/euw159][1] [1]: /lookup/doi/10.1093/europace/euw159