CD40 and atrial fibrillation: Mediation analysis showed that CD40‐mediated AIS through AF with an effect of −0.016 (effect proportion: 14.6%), CES with an effect of −0.053 (effect proportion: −107%), VD with an effect of −0.008 (effect proportion: 16.4%), and VD‐SC subtype with an effect of −0.014 (effect proportion: 18.4%) (Figure 4b).