Circulating Secretoneurin Concentrations After Cardiac Surgery: Data From the FINNish Acute Kidney Injury Heart Study

Objectives: Secretoneurin is associated with cardiomyocyte Ca2+ handling and improves risk prediction in patients with acute myocardial dysfunction. Whether secretoneurin improves risk assessment on top of established cardiac biomarkers and European System for Cardiac Operative Risk Evaluation II in patients undergoing cardiac surgery is not known. Design: Prospective, observational, single-center sub-study of a multicenter study. Setting: Prospective observational study of survival in patients undergoing cardiac surgery. Patients: A total of 619 patients undergoing cardiac surgery. Interventions: Patients underwent either isolated coronary artery bypass graft surgery, single noncoronary artery bypass graft surgery, two procedures, or three or more procedures. Procedures other than coronary artery bypass graft were valve surgery, surgery on thoracic aorta, and other cardiac surgery. Measurements and Main Results: We measured preoperative and postoperative secretoneurin concentrations and adjusted for European System for Cardiac Operative Risk Evaluation II, N-terminal pro-B-type natriuretic peptide, and cardiac troponin T concentrations in multivariate analyses. During 961 days of follow- up, 59 patients died (9.5%). Secretoneurin concentrations were higher among nonsurvivors compared with survivors, both before (168 pmol/L [quartile 1-3, 147-206 pmol/L] vs 160 pmol/L [131-193 pmol/L]; p = 0.039) and after cardiac surgery (173 pmol/L [129-217 pmol/L] vs 143 pmol/L [111-173 pmol/L]; p < 0.001). Secretoneurin concentrations decreased from preoperative to postoperative measurements in survivors, whereas we observed no significant decrease in secretoneurin concentrations among nonsurvivors. Secretoneurin concentrations were weakly correlated with established risk indices. Patients with the highest postoperative secretoneurin concentrations had worse outcome compared with patients with lower secretoneurin concentrations (p < 0.001 by the log-rank test) and postoperative secretoneurin concentrations were associated with time to death in multivariate Cox regression analysis: hazard ratio ln secretoneurin 2.96 (95% CI, 1.46-5.99; p = 0.003). Adding postoperative secretoneurin concentrations to European System for Cardiac Operative Risk Evaluation II improved patient risk stratification, as assessed by the integrated discrimination index: 0.023 (95% CI, 0.0043-0.041; p = 0.016). Conclusions: Circulating postoperative secretoneurin concentrations provide incremental prognostic information to established risk indices in patients undergoing cardiac surgery.