FP038THE EUROSCORE I AND II - AN ASSESSMENT OF THEIR VALIDITY AND PRACTICALITY TO DETERMINE THE MORTALITY OF PATIENTS UNDERGOING ELECTIVE CARDIAC SURGERY

Abstract

Introduction and Aims: The following paper was conceived as a cohort study and aimed to identify clinical and chemical parametres as risk factors for postoperative complications. The hospitals also have an interest to assess the individual risk levels of each patient before the surgery and the possible outcome of such intervention. Rising costs in the provision of health care as well as the means and ability to reduce further costs are becoming increasingly important in the political and public debate. EuroSCORE I and the later introduced EuroSCORE II were developed to predict 30 days mortality in those patients. Methods: The 865 participants all suffered from a known existing coronary heart disease with varying severity of the condition. Essentially, all patients had an underlying clinical condition of the heart or of the extracardial vessels that presented a need for a surgical intervention even though their condition was clinically stable. The study was carried out in the time from February 2010 to March 2011. To predict early mortality in cardiac surgical patients, a scoring system was developed in 1999 based on a panel of risk factors including age, gender, type of surgical intervention or heart function. As cardiac surgical mortality has significantly decreased in the last 15 years, the former EuroSCORE I was replaced by the EuroSCORE II. The new indicator includes additional factors which have been proven to influence risk. EuroSCORE II now comprises 18 factors: age, gender, renal impairment (GFR), extra-cardiac arteriopathy, poor mobility, previous cardiac surgery, chronic lung disease, active endocarditis, critical preoperative state, insulin-treated diabetes mellitus, NYHA-class, CCS class 4 angina, LV function, recent myocardial infarction, pulmonary hypertension, urgency, numbers of interventions and surgery on thoracic aorta. Results: We enrolled 865 patients (mean age 63.6 years; 68.6% males, mean BMI 27.2 kg/m2) undergoing cardiac surgery. 70% of patients (n=604) suffered from valvular heart disease while about 38% of patients (n= 327) received bypass surgery. The mean left ventricular ejection fraction was about 48%, the average NYHA class 2.7%. Renal impairment (GFR) 0.8% were liable for dialysis and 23% had diabetes mellitus (6% required insulin). Moderate pulmonary hypertension was documented in 13.6% of patients while progressed pulmonary hypertension occurred in 6.8%. In each of these patients the EuroSCORE I was calculated. For 181 patients all EuroSCORE II relevant parametres were available preoperative. Using the EuroSCORE I the mortality was estimated to be about 8.6% vs. 3.1%. The mortality was thus, as previously mentioned, considerably overrated. Using the EuroSCORE II only half of the deceased patients were accounted for. Conclusions: The EuroSCORE II offers a considerably better way of measuring mortality than the EuroSCORE I. However it is still not achieving the ideal standard. Determining the individual parametres is complicated and not entirely objective as well as time consuming. Furthermore, it can only be calculated using computer software. It was found that the preoperative assessment of the FGF-23 is a strong predictor of the outcome, postoperative complications and clinical course in patients undergoing elective cardiac surgery. FGF-23 was strongly related to mortality with an even better predictive value in the receiver operating characteristic (ROC) curve than the EuroSCORE II (area under the curve 0.800 vs. 0.725). Further studies should clarify if a preoperative measurement of FGF-23 could serve as a simple but powerful prognostic tool in patients undergoing cardiac surgery.