Soluble ST2 is associated with postoperative atrial fibrillation after cardiac surgery in postmenopausal women

Background: Postoperative atrial fibrillation (POAF) represents the most common complication following cardiac surgery. Approximately one-third of patients experiencing POAF transition to atrial fibrillation within a year, challenging the notion of POAF as merely a transient event. Soluble ST2 (sST2) is an established biomarker regarding fibrosis and myocardial stretch, however, its role in predicting the onset of POAF remains unclear. Methods: Preoperative sST2 levels have been assessed in 496 individuals with no prior history of AF who underwent elective cardiac surgery, including valve, coronary artery bypass graft surgery, or a combined procedure. Results: The average age was 70 years, and 29.4 % were female. Overall, 42.3 % developed POAF. sST2 levels were found to be significantly higher in patients with POAF. Interestingly, sST2 was only predictive of POAF in females with an adjusted OR of 1.894 (95 %CI:1.103-3.253; p = 0.021) and not males (OR:1.091; 95 % CI:0.849-1.402; p = 0.495). Furthermore, within a linear regression model it was observed that for every 1 ng/ mL increase in sST2 levels, the average POAF duration extended by 39.5 min (95 %CI:15.8-63.4 min; p = 0.001). Conclusion: sST2 predicts the onset of POAF in women but not men undergoing cardiac surgery. Furthermore, sST2 levels were associated with the subsequent burden of POAF. Thus, assessment of sST2 in addition to clinical risk factors could improve risk stratification for development of POAF following elective cardiac surgery.