Impact of a single non-sex-related stroke risk factor on atrial fibrillation and oral anticoagulant outcomes: a systematic review and meta-analysis

AIMS: Oral anticoagulants (OACs) are crucial for treating atrial fibrillation (AF) patients at high thromboembolic risk. However, in AF patients at intermediate thromboembolic risk with a single non-sex-related stroke risk factor (CHA2DS2-VASc score 1 in men, 2 in women), guidelines advise to consider starting anticoagulation, which may result in OAC non-initiation due to underestimation of the thromboembolic risk of a single stroke risk factor and overestimation of the OAC-related bleeding risk. A critical appraisal of the role of OACs and the benefit-risk profile of non-vitamin K antagonist oral anticoagulants (NOACs) compared with vitamin K antagonists (VKAs) in this patient subgroup are needed.

METHODS AND RESULTS: This systematic review provides an overview of literature on the effectiveness and safety of OACs in AF patients with a single non-sex-related stroke risk factor after searching Medline and Embase. Differences between individual stroke risk factors regarding the ischaemic stroke risk in non-anticoagulated AF patients are identified in a meta-analysis, demonstrating the highest increased risk in patients aged 65-74 years old or with diabetes mellitus, followed by heart failure, hypertension and vascular disease. Furthermore, meta-analysis results favour NOACs over VKAs, given their equal effectiveness and superior safety in AF patients at intermediate thromboembolic risk (HR 0.93, 95% CI 0.65 to 1.34 for stroke or systemic embolism; HR 0.60, 95% CI 0.45 to 0.80 for major bleeding; HR 0.48, 95% CI 0.14 to 1.59 for intracranial bleeding; HR 0.58, 95% CI 0.47 to 0.71 for mortality).

CONCLUSION: Our systematic review with meta-analysis favours the use of anticoagulation in AF patients with a single non-sex-related stroke risk factor, especially when age ≥65 years or diabetes mellitus is present, with a preference for NOACs over VKAs.