Prognosis

Why?

AF increases the risk of stroke, especially with other risk factors

Strokes per year a	no other risk factors  (95% CI)	1+ other risk factor  (95% CI)
aged< 65	1.0%  (0.3% to 3.1%)	4.9%  (3.0% to 8.1%)
aged 65 to 75	4.3%  (2.7% to 7.1%)	5.7%  (3.9% to 8.3%)
aged > 75	3.5%  (1.6% to 7.7%)	8.1%  (4.7% to 14%)

The risk of stroke increases with increasing numbers of risk factors

Number of prognostic factors a	rate of thromboembolism (95% CI)
3 or more	19%  (12% to 30%)
1 or 2	6.0%  (4.1% to 8.8%)
0	1.0%  (0.2% to 4.0%)