Prevention

Anticoagulate patients with atrial fibrillation ^a

Why?

• It reduces recurrent stroke and other vascular events, but major extracranial bleeds are more common. ^a

Patients with AF who are anticoagulated have fewer recurrent strokes, but more major extracranial bleeds

Patient	Treatment	Comparison	Outcome	CER	OR (95% CI)	NNT (95% CI)
stroke and AF a	anticoagulation	aspirin	recurrent stroke at 2 years	23%	0.36 (0.22 to 0.59)	8 (6 to 12)
			all vascular events at 2 years	30%	0.55 (0.36 to 0.83)	9 (6 to 27)
			major extracranial bleed at 2 years	0.87%	4.65 (1.66 to 12.99)	-33 (-180 to -11)

Note:

• Early anticoagulation in all strokes has no effect on death, dependence or recurrent stroke. ^a
• Patients are less likely to have deep vein thrombosis or pulmonary embolism, but are more likely to have a major extracranial bleed. ^a
• Anticoagulation for presumed non-embolic ischaemic stroke or transient- ischaemic attack has no clear effect on death or recurrent stroke. ^a

Early anticoagulation reduces DVT and PE, but causes more extracranial bleeding

Patient	Treatment	Comparison	Outcome	CER	OR (95% CI)	NNT (95% CI)
stroke a	anticoagulation within 2 weeks of stroke	no anticoagulation	DVT during treatment period	44%	0.21 (0.15 to 0.29)	3 (3 to 4)
			symptomatic PE during treatment period	0.93%	0.61 (0.45 to 0.83)	280 (200 to 640)
			major extracranial haemorrhage during treatment period	3.6%	0.76 (0.65 to 0.88)	-120 (-240 to -81)