Predictors for preoperative atrial fibrillation were hypertension (OR 1.784, 95% CI 1.136–2.802, p < 0.05), C-reactive protein at admission (OR 1.329, 95% CI 1.048–1.662, p < 0.05), systemic inflammatory response index at admission (OR 2.137, 95% CI, 1.678–2.721 p < 0.05), Age-Adjusted Charlson Comorbidity Index (OR 1.542, 95% CI 1.326–1.794, p < 0.05), low potassium(OR 2.538, 95% CI 1.623–3.968, p < 0.05), anemia(OR 1.542, 95% CI 1.326–1.794, p < 0.05). The gene discussed is CRP; the disease is anemia (phenotype).