APOA1 and atrial fibrillation: AF apoA-I correlated positively with serum HDL cholesterol (rs = 0.384, P = 0.004), showed a strong positive correlation with AF total cholesterol (rs = 0.736, P < 0.001) and AF LDL cholesterol (rs = 0.642, P < 0.001), and a moderate positive correlation with AF HDL cholesterol (rs = 0.582, P < 0.001).