ObjectiveTo detect the expression of PITX2 and KCNQ1 in the left atrial appendage of patients with atrial fibrillation after modified mini-maze procedure, and to detect the clinical risk factors of different types of atrial fibrillation.MethodsWe collected left atrial appendage tissue of 59 atrial fibrillation patients who received modified mini-maze procedure and left atrial appendectomy from February 2017 to August 2018. The expression levels of PITX2 and KCNQ1 of left atrial appendage tissue were quantitatively analyzed by western blotting assay between paroxysmal attial fibrillation and persistent atrial fibrillation groups. The correlation between protein expression and prognosis after surgery was also analyzed based on clinical data.ResultsBinary-logistic regression analysis showed that KCNQ1 expression level was an independent risk factor for the progression from paroxysmal atrial fibrillation to persistent atrial fibrillation. Receiver operating characteristic (ROC) curve confirmed that KCNQ1 expression level (the ratio of KCNQ1 to actin in the analysis) was 0.60, which was the best cut-off point for the progression of paroxysmal atrial fibrillation to persistent atrial fibrillation.ConclusionHigh expression of KCNQ1 in left atrial appendage is a risk factor for progression from paroxysmal atrial fibrillation to persistent atrial fibrillation.