Oral anticoagulants in patients with atrial fibrillation at low stroke risk: a multicentre observational study

Abstract

Aims There is currently no consensus on whether atrial fibrillation (AF) patients at low risk for stroke (one non-sex-related CHA2DS2-VASc point) should be treated with an oral anticoagulant. Methods and results We conducted a multi-country cohort study in Sweden, Denmark, Norway, and Scotland. In total, 59 076 patients diagnosed with AF at low stroke risk were included. We assessed the rates of stroke or major bleeding during treatment with a non-vitamin K antagonist oral anticoagulant (NOAC), a vitamin K antagonist (VKA), or no treatment, using inverse probability of treatment weighted (IPTW) Cox regression. In untreated patients, the rate for ischaemic stroke was 0.70 per 100 person-years and the rate for a bleed was also 0.70 per 100 person-years. Comparing NOAC with no treatment, the stroke rate was lower [hazard ratio (HR) 0.72; 95% confidence interval (CI) 0.56–0.94], and the rate for intracranial haemorrhage (ICH) was not increased (HR 0.84; 95% CI 0.54–1.30). Comparing VKA with no treatment, the rate for stroke tended to be lower (HR 0.81; 95% CI 0.59–1.09), and the rate for ICH tended to be higher during VKA treatment (HR 1.37; 95% CI 0.88–2.14). Comparing NOAC with VKA treatment, the rate for stroke was similar (HR 0.92; 95% CI 0.70–1.22), but the rate for ICH was lower during NOAC treatment (HR 0.63; 95% CI 0.42–0.94). Conclusion These observational data suggest that NOAC treatment may be associated with a positive net clinical benefit compared with no treatment or VKA treatment in patients at low stroke risk, a question that can be tested through a randomized controlled trial. Key question What is the association between anticoagulant treatment and stroke and bleeding rate, in patients with one non-sex-related risk factor for stroke? Key findings Take-home message These observational data suggest that NOAC treatment may be associated with a positive net clinical benefit compared with no treatment or VKA treatment in patients at low stroke risk, a hypothesis that can be tested through a randomized controlled trial.

Predictors of Symptomatic Intracranial Hemorrhage after Endovascular Thrombectomy in Acute Ischemic Stroke: A Systematic Review and Meta-Analysis

“…However, the present study indicates that atrial fibrillation was not associated with sICH risk. In recent years, this may be related to clinicians’ more scientific and rational oral anticoagulant use under the guidance of guidelines and RCTs [43, 44]. This study did not consider oral anticoagulants and antiplatelet therapy as the risk factors for sICH, which may partially support this hypothesis.…”

Atrial Fibrillation Detection and Management in Hypertension

“…26 A recent large, multi-country, cohort study of 59 076 patients at low stroke risk (hypertension in 23%) and with newly diagnosed AF suggests that nonvitamin K antagonist oral anticoagulant treatment may be associated with a 28% lower rate for stroke without increasing intracranial bleeding compared with no anticoagulant treatment. 27 Whether or not oral anticoagulation in patients at low stroke risk is clinically meaningful and cost-effective is a matter for debate, 28 and should be tested through a randomized controlled trial.…”

The gray areas of oral anticoagulation for prevention of thromboembolic events in atrial fibrillation patients

“…It seems that oral anticoagulation conferred a lower risk of TEE in AF patients who had a single nonsex-based risk factor for stroke, 11 but such results have not been confirmed by a Korean registry that found higher TEE in a large low-risk cohort. 12 The default position is to offer stroke prevention through anticoagulant drugs unless patients are at minimal risk (Table 1).…”

“…It seems that oral anticoagulation conferred a lower risk of TEE in AF patients who had a single nonsex-based risk factor for stroke, 11 but such results have not been confirmed by a Korean registry that found higher TEE in a large low-risk cohort 12 …”

“…12 The default position is to offer stroke prevention through anticoagulant drugs unless patients are at minimal risk (Table 1). [10][11][12] These patients with relatively lower risk of stroke are not well represented in pivotal AF trials, and future studies considering potential hypercoagulability states are warranted (Table 2).…”