In a related editorial, the authors highlight the limitations of this study in the small number of participants and the short-term nature of the study, and conclude that longer-term safety of moderate- and high-dose consumption of caffeine, including in popular energy drinks and in patients at high risk for arrhythmias, remains unknown. However, they suggest that, for the time being, it seems reasonable to reassure patients that modest caffeine consumption appears to be safe, including for most patients with heart failure.