To investigate the relationship between endothelin-1 level and new onset atrial fibrillation after isolated aortic valve replacement.

The clinical data of 119 patients who underwent isolated aortic valve replacement in the Structural Heart Surgery Center, Beijing Anzhen Hospital, Capital Medical University from June 2017 to June 2019 were retrospectively analyzed. According to whether the patients had postoperative new onset atrial fibrillation, they were divided into postoperative atrial fibrillation group (n=28) and non postoperative atrial fibrillation group (n=91). After the successful general anesthesia, the patients in both groups were taken to the supine position, routinely disinfected and covered with towels, a median chest incision was made and the sternum was split. The pericardium was cut and suspended. After heparinization, the ascending aorta and right atrium were intubated with two-step drainage tubes to establish extracorporeal circulation. The circulation was switched, cooled, blocked, the aorta was cut, the pathological condition of the aortic valve was explored, the pathological aortic valve was cut off, and the artificial aortic valve (mechanical valve or biological valve) of appropriate size was selected for replacement, and the whole week was sutured intermittently. After the aortic incision was closed, rewarmed, exhausted, and then the circulation was opened. After parallel stabilization, the cardiopulmonary bypass was stopped and the arteriovenous pipeline was pulled out. Routine hemostasis, chest closure, and the operation was end. The factors most likely to affect the occurrence of postoperative atrial fibrillation including the preoperative data [gender, age, body mass index, endothelin-1 level, basic diseases, New York Heart Association (NYHA) cardiac function classification, echocardiographic indicators], intraoperative data (intraoperative cardiopulmonary bypass time, aortic occlusion time), and postoperative data [postoperative mechanical ventilation time, postoperative hospital stay, number of cases undergoing thoracotomy hemostasis, and what type of artificial valve (mechanical valve or biological valve) was used] were collected. The data were compared by t test, nonparametric test and chi-square test; and the cut-off value of endothelin-1 for predicting postoperative new onset atrial fibrillation was determined by receiver operator characteristic (ROC) curve, univariate and multivariate Logistic regression were used to analyze the risk factors associated with postoperative new onset atrial fibrillation.

(1) The age of patients in the postoperative atrial fibrillation group was (53.0 ± 12.1) years old, higher than that in the non postoperative atrial fibrillation group [(47.1±13.6) years old], the preoperative endothelin-1 level was 0.43 ± 0.19, higher than that in the non postoperative atrial fibrillation group (0.27 ± 0.14), the proportion of patients with NYHA grade≥3 was 14.3%(4/28), higher than that in the non postoperative atrial fibrillation group [4.4%(4/91)], the left atrial diameter was (40.6±4.8) mm, higher than that in the non postoperative atrial fibrillation group [(36.7±5.2) mm], the proportion of patients with aortic stenosis was 39.3%(11/28), lower that that in the non postoperative atrial fibrillation group [60.4%(55/91)], the differences between the two groups were statistically significant (P<0.05); there was no atatistically significant differences in other preoperative data between the two groups (P> 0.05). (2) The intraoperative cardiopulmonary bypass time was (113.9±41.7) min and aortic blockade time was (75.3±24.1) min in postoperative atrial fibrillation group, and the intraoperative cardiopulmonary bypass time was (108.6±46.3) min and aortic blockade time was (72.5±31.4) min in non postoperative atrial fibrillation group, the differences were no statistically significant between the two groups (t=-0.547, -0.432; P=0.59, 0.67). (3) The postoperative mechanical ventilation time and postoperative hospitalization time of patients in the postoperative atrial fibrillation group were (24.7±14.3) h and (9.1±3.6) d respectively, which were higher than those in the non postoperative atrial fibrillation group [(19.6±9.5) h, (7.6±2.9) d]; the proportion of patients with mechanical valve replacement was 85.7%(24/28), lower than that in the non postoperative atrial fibrillation group [96.7%(88/91)], and the proportion of patients with biological valve replacement was 14.3% (4/28), higher than that in the non postoperative atrial fibrillation group [3.3% (3/91)], the differences between the two groups were statistically significant (P<0.05). The rate of postoperative hemostasis in the postoperative atrial fibrillation group was 3.6% (1/28), which was higher than that in the no postoperative atrial fibrillation group [2.2% (2/91)], and there was no statistically significant difference between the two groups (P>0.05). (4) ROC curve was used to analyze the value of endothelin-1 in predicting postoperative new onset atrial fibrillation after surgery, the area under the curve was 0.76, 95%CI: 0.66-0.85, the cut-off value was 0.265 pmol/L, the specificity was 0.75, and the sensitivity was 0.63. According to the cut-off value, patients were divided into endothelin-1>0.265 group (n=55) and endothelin-1<0.265 group (n=64). The preoperative, intraoperative and postoperative data of the two groups were compared, and the results showed that the left atrial diameter in the endothelin-1>0.265 group was larger than that in the endothelin-1<0.265 group, the proportion of patients with aortic valve stenosis was lower than that in the endothelin-1<0.265 group, and the incidence of postoperative atrial fibrillation in the endothelin-1>0.265 group (38.2%) was significantly higher than that in the endothelin-1< 0.265 group (10.9%), and the differences were statistically significant(P<0.05). And there was no significant difference in other comparisons (P>0.05). Univariate Logistic regression analysis was performed on the collected patient data and it was found that age, NYHA grade≥ 3, left atrial diameter, aortic valve stenosis, mechanical ventilation time, replacement of biological valve and endothelin-1 > 0.265 pmol/L were all associated with the occurrence of postoperative new onset atrial fibrillation; after multivariate regression Logistic analysis of the above indicators, it was found that only left atrial diameter, replacement biological valve and endothelin-1>0.265 pmol/L were independently related to the occurrence of postoperative new onset atrial fibrillation.

In patients undergoing isolated aortic valve replacement, in addition to left atrial diameter and replacement biological valve, high endothelin-1 level is also independent risk factor postoperative new onset atrial fibrillation.