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

OBJECTIVES: To 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. DESIGN: A prospective, observational multicenter cohort study. SETTING: Three cardiac surgical centers in the Netherlands between 2019 and 2021. Recruitment was on hold between March and May 2020 due to COVID-19. PATIENTS: A total of 427 patients aged 60 years and older who underwent elective on-pump cardiac surgery. MEASUREMENTS AND MAIN RESULTS: The primary endpoint was a 30-day PRBC transfusion. Secondary endpoints were postoperative major complications within 30 days (eg, acute kidney injury, sepsis), and new onset of clinically significant disability within 120 days of surgery. Iron status was evaluated before surgery. 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% CI 0.9-1.8: p = 0.227) or new onset of clinically significant disability (ARR 2.0; 95% CI 0.9-4.6: p = 0.098). However, the risk of postoperative major complications was increased in patients with an abnormal iron status (ARR 1.7; 95% CI 1.1-2.5: p = 0.012). CONCLUSIONS: An abnormal iron status before elective cardiac surgery was associated with an increased risk of postoperative major complications but not with PRBC transfusion or a new onset of clinically significant disability.

Preoperative anaemia and outcome after elective cardiac surgery: a Dutch national registry analysis.

BACKGROUND: Previous studies have shown that preoperative anaemia in patients undergoing cardiac surgery is associated with adverse outcomes. However, most of these studies were retrospective, had a relatively small sample size, and were from a single centre. The aim of this study was to analyse the relationship between the severity of preoperative anaemia and short- and long-term mortality and morbidity in a large multicentre national cohort of patients undergoing cardiac surgery. METHODS: A nationwide, prospective, multicentre registry (Netherlands Heart Registration) of patients undergoing elective cardiac surgery between January 2013 and January 2019 was used for this observational study. Anaemia was defined according to the WHO criteria, and the main study endpoint was 120-day mortality. The association was investigated using multivariable logistic regression analysis. RESULTS: In total, 35 484 patients were studied, of whom 6802 (19.2%) were anaemic. Preoperative anaemia was associated with an increased risk of 120-day mortality (adjusted odds ratio [aOR] 1.7; 95% confidence interval [CI]: 1.4-1.9; P<0.001). The risk of 120-day mortality increased with anaemia severity (mild anaemia aOR 1.6; 95% CI: 1.3-1.9; P<0.001; and moderate-to-severe anaemia aOR 1.8; 95% CI: 1.4-2.4; P<0.001). Preoperative anaemia was associated with red blood cell transfusion and postoperative morbidity, the causes of which included renal failure, pneumonia, and myocardial infarction. CONCLUSIONS: Preoperative anaemia was associated with mortality and morbidity after cardiac surgery. The risk of adverse outcomes increased with anaemia severity. Preoperative anaemia is a potential target for treatment to improve postoperative outcomes.