Ratio of LDL- to HDL-associated platelet-activating factor acetylhydrolase may be a marker of inflammation in patients with paroxysmal atrial fibrillation

Background A higher plasma concentration of highly-sensitive C-reactive protein (hs-CRP) has been found in patients with atrial fibrillation (AF). In addition, low-density lipoprotein (LDL)-associated platelet-activating factor acetylhydrolase (L-PAF-AH) is associated with inflammation. Therefore, the association between AF and PAF-AH was examined. Methods and Results Eighty subjects who were not taking aspirin or statin were investigated, and classified into paroxysmal AF (n = 41) and normal sinus rhythm (NSR, n = 39) groups. The lipid profile was analyzed by capillary isotachophoresis (cITP), plasma hs-CRP, plasma PAF-AH, high-density lipoprotein (HDL)-associated (H-PAF-AH), and L-PAF-AH. Although there were no significant differences in total cholesterol, HDL, LDL, hs-CRP, or plasma PAF-AH between the 2 groups, L-PAF-AH and the L-PAF-AH/H-PAF-AH ratio in the paroxysmal AF group were both significantly higher than in the NSR group. Interestingly, the ratio of L-PAF-AH to H-PAF-AH positively correlated with the left atrial diameter in all subjects. Although there were no differences in plasma lipoprotein subfractions, as characterized by cITP, slow-migrating LDL positively correlated with L-PAF-AH in both groups. Conclusions The distribution of PAF-AH was associated with paroxysmal AF and may be a marker of inflammation in patients with paroxysmal AF. Antiinflammatory and antioxidant therapy that targets these factors might be effective for preventing paroxysmal AF.