Annual influenza vaccination can be useful in lower- ing stroke risk in patients at risk of stroke (Class IIa; Level of Evidence B). 3. Measurement of inflammatory markers such as hs- CRP or lipoprotein-associated phospholipase A2 in patients without CVD may be considered to iden- tify patients who may be at increased risk of stroke, although their usefulness in routine clinical practice is not well established (Class IIb; Level of Evidence B). 4. Treatment of patients with hs-CRP >2.0 mg/dL with a statin to decrease stroke risk might be considered (Class IIb; Level of Evidence B). 5. Treatment with antibiotics for chronic infections as a means to prevent stroke is not recommended (Class III; Level of Evidence A). Antiplatelet Agents for Primary Prevention of Stroke Aspirin use is associated with an increased risk of gastrointes- tinal bleeding. For example, 1 observational study found that the overall hemorrhagic event incidence was 5.58 (95% CI, 5.39 5.77) per 1000 person-years for aspirin users compared nonusers (incidence rate ratio, 1.55; 95% CI, 1.48 1.63).872 A meta-analysis of 9 clinical trials including 50868 subjects found no overall benefit of aspirin for the primary preven- with no heterogeneity among trials.873 Similarly, a second meta-analysis of 9 trials with 100076 subjects found that aspirin reduced the risk of ischemic stroke (RR, 0.86; 95% CI, 0.75 0.98), but this benefit was offset by an increase in hemorrhagic stroke (RR, 1.36; 95% CI, 1.01 1.82), again with no heterogeneity among trials.874 A third meta-analysis had similar results (risk of stroke, 0.20%/y versus 0.21%/y, other stroke, 0.16%/y versus 0.18%/y, P=0.08, aspirin versus Taken together, these results reflect risk but no benefit of aspirin for the prevention of a first stroke in the general population. 