It is humbling to consider that not long ago, the optimal thromboembolic risk management in patients with atrial flutter (AFl), let alone atrial fibrillation (AF), was considered an unknown. Indeed, it was only as recently as 2001 that the issue was addressed in published guidelines. Even then, the recommendation was a tepid one, reflecting the paucity of data to provide strong guidance: ‘Until more robust data become available, and although the overall thromboembolic risk associated with atrial flutter can be lower than with AF, it seems prudent to estimate risk by use of similar stratification criteria’. Up until that time, the argument for anticoagulation in patients with AF was gaining strength, but the data for AFl were limited.

Up to 2001, the data consisted mostly of small, observational and retrospective studies subject to the usual limitations of small event rates and heterogeneity with regard to important inclusion or exclusion criteria such as the presence or absence of structural heart disease (valvular disease, cardiomyopathy), the presence or absence of hypertension and importantly the coexistence of AF in a particular patient with AFl. Despite the heterogeneity, however, the data began to paint a picture of increased thromboembolic risk in patients with flutter, particularly those undergoing cardioversion.1

In their Heart publication, Vadmann et al2 offer a systematic review of the literature related to AFl and thromboembolic risk. A key study included in the present review was a case–control study by Biblo et al3 that examined 8-year outcomes in 749 988 Medicare patients …