Abnormal Iron Status and Adverse Outcome After Elective Cardiac Surgery: A Prospective, Observational Multicenter Study

Abstract

ObjectivesTo investigate the incidence of preoperative abnormal iron status and its association with packed red blood cell (PRBC) transfusion, postoperative major complications, and new onset of clinically significant disability in patients undergoing elective cardiac surgery. DesignProspective, observational multicenter cohort study. SettingThree heart surgical centers in the Netherlands, between 2019 and 2021. Recruitment was on hold between March and May 2020, due to COVID-19. Patients427 patients aged 60 years and older who underwent elective on-pump cardiac surgery. Measurements and Main ResultsPrimary endpoint was 30-day packed red blood cell (PRBC) transfusion. Secondary endpoints were postoperative major complications within 30 days (e.g., acute kidney injury, sepsis), and new onset of clinically significant disability within 120 days within surgery. Iron status was evaluated prior to surgery. An abnormal iron status was present in 45.2% of patients (n=193), and most frequently the result of iron deficiency (27.4%, n = 117). An abnormal iron status was not associated with PRBC transfusion (adjusted relative risk (ARR) 1.2; 95% confidence interval (95% CI) 0.9 to 1.8: p = 0.227) or new onset of clinically significant disability (ARR 2.0; 95% CI 0.9 to 4.6: p = 0.098). However, the risk of postoperative major complications was increased in patients with an abnormal iron status (ARR 1.7; 95% CI 1.1 to 2.5: p = 0.012). ConclusionsAn abnormal iron status prior to elective cardiac surgery was associated with an increased risk of postoperative major complications, but not with PRBC-transfusion or new onset of clinically significant disability.