Numerous reports have emphasized the need for reduction in transfusions of allogeneic red blood cells (RBC) due to increased morbidity and mortality. Nevertheless, transfusion rates are still high in several cardiac surgery institutions. Reports on long-term survival after cardiac surgery and RBC transfusion are few. Data from the Western Denmark Heart Registry (WDHR) were used to identify all (25 117) adult cardiac surgery performed in four centres during 1999–2010. Patients with multiple entries (1049), re-do cardiac surgery (985), special/complex procedures (2329), dying within 30 days (668) and not eligible for follow-up (85) were excluded leaving a cohort of 20 001. Registration in the WDHR is mandatory. WDHR and the unique Danish Civil Registration System with continuous sequential updates of the Danish population ensure that all patients and outcomes are accounted for. Kaplan–Meier survival plot for low-risk patients (EuroSCORE 0–4), undergoing simple cardiac surgery showed a significantly lower estimated survival after >4500 days (0.637 vs. 0.745) when receiving perioperative RBC transfusion (P < 0.0001). The difference was less evident in patients with EuroSCORE 5–9 (0.373 vs. 0.4436, P < 0.0001), while high-risk patients showed no difference. Adjusted risk ratio, after RBC transfusion, containing among others age, sex, EuroSCORE and diabetes, was 1.83 (95% CI (confidence interval) 1.67–2.01). The survival rate was independent of up till six units of RBC. Long-term follow-up of low-risk patients undergoing simple cardiac surgery demonstrates a more than 10% higher mortality when receiving perioperative RBC transfusion. Even transfusion of 1–2 units seems to carry a risk of that magnitude.

Introduction: European system for cardiac operative risk evaluation (EuroSCORE) is a valuable tool in control of the quality of cardiac surgery. However, the validity of the risk score for the individual patient may be questioned. The present study was carried out to investigate whether the continued fall in short-term mortality reflects an actual improvement in late mortality, and subsequently, to investigate EuroSCORE as predictor of 1-year mortality. Methods: A population-based cohort study of 25,602 patients from a 12-year period from three public university hospitals undergoing coronary artery bypass grafting (CABG) or valve surgery. Analysis was carried out based on EuroSCORE, age and co-morbidity factors (residual EuroSCORE). Results: During the period the average age increased from 65.1 ± 10.0 years to 68.9 ± 10.7 years (P < 0.001, one-way ANOVA), and the number of females increased from 26.0% to 28.2% (P = 0.0012, Chi-square test). The total EuroSCORE increased from 4.67 to 5.68 while the residual EuroSCORE decreased from 2.64 to 1.83. Thirty-day mortality decreased from 4.07% in 1999-2000 to 2.44% in 2011-2012 (P = 0.0056; Chi-square test), while 1-year mortality was unchanged (6.50% in 1999-2000 vs. 6.25% in 2011-2012 [P = 0.8086; Chi-square test]). Discussion: The study demonstrates that both co-morbidity and age has a great impact on 30-day mortality. However, with time the impact of co-morbidity seems less. Thus, age is more important than co-morbidity in late mortality. The various developments in short and long-term mortality are not readily explained. Conclusion: Although 30-day mortality of CABG and valve surgery patients has decreased during the 12-year period, the 1-year mortality remains the same.