Abstract: Abstract: Objective To investigate the relationship between plasma big endothelin-1 (Big ET-1) level and prognosis of paroxysmal atrial fibrillation (PAF) in patients at admission. Methods A total of 200 patients with PAF were enrolled,and divided into survival group (n=164) and cardiovascular death group (n=36) according to the follow-up results. Clinicaland laboratory data of sex, age and Big ET-1 level were collected. Cox proportional hazard model was used to analyze the relationship between plasma level of Big ET-1 and prognosis of PAF patients at admission. The prognostic effect of plasma level of Big ET-1 on the prognosis of PAF patients was evaluated by drawing ROC, and then the area under the curve was calculated. The cardiovascular cumulative mortality curves of PAF patients with different plasma levels of Big ET-1 were drawn by Kaplan-Meier method and compared by Log-Rank method. Results There were lower levels of age, systolic blood pressure, hypertension, chronic renal failure, heart failure, plasma Big ET-1, plasma amino-terminal pro-brain natriuretic peptide (NT-pro-BNP), left atrial diameter (LAD), left ventricular diameter (LVD), CHA2DS2-VASc score >2 points in survival group than those of the death group (P＜0.05), and higher levels of estimated glomerular filtration rate(eGFR) and ejection fraction (EF) in survival group than those of the death group (P＜0.05). Multivariate Cox regression analysis showed that the higher plasma level of Big ET-1 was the risk factor for cardiovascular death in PAF patients (P＜0.05). It showed a certain value in predicting the prognosis of PAF when the plasma level of Big ET-1 was 0.75 pmol/L. The results of Kaplan-Meier analysis showed that the cardiovascular cumulative mortality was significantly higher in patients with plasma level of Big ET-1 > 0.75 pmol/L than that of patients with plasma level of Big ET-1 ＜ 0.75 pmol/L (P＜0.05).Conclusion The increased plasma level of Big ET-1 at admission is closely related to the increased risk of cardiovascular mortality in PAF patients. The plasma level of Big ET-1 at admission can be used as an important biological marker for predicting the prognosis of PAF.

Key words: atrial fibrillation, cardiovascular diseases, plasma, prognosis, ROC curve, risk factors, Big ET-1