Impact of the definition of renal dysfunction on EuroSCORE performance.

AIM: Renal dysfunction is an important variable in the EuroSCORE (European System for Cardiac Operative Risk Evaluation) model and is currently defined as creatinine >200 mmol/L. The aim of this study was to examine whether using other definitions of renal dysfunction could improve the predictive ability of the EuroSCORE. METHODS: Between January 2004 and January 2006, 1 205 patients underwent cardiac surgery. Their preoperative glomerular filtration rate and EuroSCORE were calculated. Four recalibrated EuroSCORE models were constructed using 1) creatinine as a binary variable; 2) creatinine as a continuous variable; 3) glomerular filtration rate as a categorical variable; or 4) glomerular filtration rate as a continuous variable. The predictive ability of these models was assessed using receiver operating characteristic curve analysis. RESULTS: Hospital mortality was 4% (N.=47). Receiver operating characteristic curve values were: 0.78 for the original EuroSCORE, 0.80 for the recalibrated binary creatinine model, 0.83 for the continuous creatinine model, 0.83 for the categorical glomerular filtration rate model, and 0.82 for the continuous glomerular filtration rate model. CONCLUSIONS: The use of creatinine as a continuous variable or glomerular filtration rate as a categorical or continuous variable improves the predictive accuracy of the EuroSCORE model for hospital mortality. Given the increasing incidence of preoperative renal dysfunction and its impact on hospital mortality, future risk stratification models should include continuous creatinine or glomerular filtration rate rather than creatinine as a binary variable.

Short-term and 5-year outcome after primary isolated coronary artery bypass graft surgery: results of risk stratification in a bilocation center.

OBJECTIVE: We retrospectively investigated the short and mid-term outcome of non-emergent primary isolated coronary artery bypass graft (CABG) surgery in relation to risk stratification in the fully equipped university location (FE) and the low volume, limited facility location (LVLF) of our department. METHODS: Between September 1995 and December 1996, 832 patients were referred to our department to undergo a primary isolated CABG operation. The surgical team selected 482 patients (58%) as being at low-risk. These were treated in the LVLF hospital. The other 350 patients with mixed-risk were treated in the FE hospital. The selection consisted primarily of exclusion of patients with moderate or poor left ventricular function, severe COPD or renal impairment, from surgery in the LVLF location. Finally, the prognostic value of the EuroSCORE and the Parsonnet score was tested on our patient population. RESULTS: Overall in-hospital mortality was 1.6% (13 patients). One patient died in the LVLF group (0.2%) and 12 patients (3.4%) in the FE group. LVLF patients experienced less complications during the hospital period compared to the FE patients (5 versus 21%; P=0.0001). The Parsonnet risk model and the EuroSCORE risk model showed both a good relation with in-hospital mortality. After discharge, an increased risk of late mortality was observed up to 1 year postoperative in the FE group compared to the LVLF group (2.7 versus 0.5%; P=0.01). Risk factors for 5-year mortality were pre-operative renal impairment (blood creatinine >150 micromol/l) (hazard ratio (HR): 2.8; 95% confidence interval (CI): 1.4-5.5), diabetes (HR: 2.1; 95% CI: 1.3-3.5), impaired LVEF (HR: 1.9; 95% CI: 1.2-3.0), COPD (HR: 1.9; 95% CI: 1.1-3.5) and older age (HR: 1.07 per year; 95% CI: 1.01-1.10). Lipid-lowering therapy was a predictor of lower mortality at 5-years (HR: 0.5; 95% CI: 0.4-0.9). CONCLUSION: By careful decision making, selection of low-risk patients for a low volume and limited facility location resulted in excellent in-hospital survival with very low complication rates.