Circulating BMP10 Levels Associate with Late Postoperative Atrial Fibrillation and Left Atrial Endomysial Fibrosis

Background Serum bone morphogenetic protein 10 (BMP10) blood levels are a marker for history of atrial fibrillation (AF) and for major adverse cardiovascular events in AF-patients, including stroke, AF-recurrences after catheter ablations, and mortality. The predictive value of BMP10 in patients undergoing cardiac surgery and association with morphological properties of atrial tissues are unknown. Objective To study the correlation between BMP10 levels and pre-operative clinical traits, occurrence of early and late postoperative atrial fibrillation (POAF), and atrial fibrosis in patients undergoing cardiac surgery. Methods Patients with and without preoperative AF history undergoing first cardiac surgery were included (RACE V, n=147). Pre-operative blood biomarkers were analyzed, left (n=114) and right (n=125) atrial appendage biopsies were histologically investigated following WGA-staining, and post-operative rhythm was monitored continuously with implantable loop recorders (n=133, 2.5yrs). Results Adjusted multinomial logistic regression indicated that BMP10 accurately reflects a history of persistent AF (OR=1.24, 95%CI: 1.10-1.40, p=0.001), similar to NT-pro-BNP. BMP10 levels were associated with increased late-POAF90 occurrence after adjusting for age, sex, AF history, and early-POAF occurrence (HR=1.07 [per 0.1ng/ml increase], 95%CI: 1.00-1.14, p=0.041). Left atrial endomysial fibrosis (St.β=0.22, p=0.041), but not overall fibrosis (St. β=0.12 , p=0.261), correlates with circulating BMP10, after adjusting for age, sex, AF history, reduced LVF, and valvular surgery indication. Conclusion Increased BMP10 levels were associated with persistent AF-history, increased late-POAF incidence, and LAA endomysial fibrosis in a diverse sample of patients undergoing cardiac surgery.