Neefs J, Klamer TA, Krul, SPJ, et al. - The need for anticoagulation was assessed in patients with atrial fibrillation (AF) with a 2DS2-VASc score">CHA2DS2-VASc score of 1, regardless of sex, via this systematic review of five studies with 37,030 participants. These relevant studies were identified from PubMed, via a systematic search from inception to July 31, 2017. The included studies reported thromboembolic risk per risk factor of the 2DS2-VASc score">CHA2DS2-VASc score in AF patients not treated with an anticoagulant. The lowest event rates were reported in patients with vascular disease, while patients without comorbidities, aged 65–74 years, showed the highest event rates, numerically. Age 65–74 years was related to the highest and most consistent risk, but findings revealed distinct thromboembolic risk between the risk factors of the 2DS2-VASc score">CHA2DS2-VASc score in patients with AF. However, increased thromboembolic risk, which was significant and clinically relevant, was exhibited by all. Stroke risk may also be modified by differences within risk factors, besides the differences between risk factors of the 2DS2-VASc score">CHA2DS2-VASc score.