New-onset atrial fibrillation (NOAF) is a common finding during the acute phase of acute myocardial infarction (AMI) with an incidence rate ranging from 6% to 21% [1]. Although there are numerous studies demonstrating that patients with post-MI NOAF generally have a poor cardiovascular (CV) outcome when compared to those with sinus rhythm [2,3], it is important to realize that the long-term prognosis also can be largely varied across this high-risk population due to differences in patients' comorbidities, medical treatments, as well as AF characteristics [4–6].