OBJECTIVE: To compare the national samples of patients who underwent
isolated coronary artery bypass grafting (CABG) during the European System
for Cardiac Operative Risk Evaluation (EuroSCORE) trial in order to evaluate
national differences in epidemiology, patient risk profile and surgical
methods. METHODS: From September to November 1995, 11731 patients had CABG
in the six largest contributing nations to the EuroSCORE project: Germany,
UK, Spain, Finland, France and Italy. The Chi-square and Kruskal-Wallis
tests were applied to obtain an international comparison of patient general
status, including pre-operative risk factors, cardiac status, critical
pre-operative states, rare conditions, urgency of surgery, angina status,
coronary lesions, procedures and EuroSCORE risk assessment. RESULTS: Large
national samples (from 984 patients in Finland to 3138 in Germany)
identified significant differences in epidemiology, risk profile and
surgical practice. Regarding epidemiology, CABG accounted for 62.8% of adult
cardiac surgery, with a range of 46.2 in Spain to 77.7% in Finland
(P<0.001). The mean age was 62.9 years (61.4 in Britain to 64.4 in
France, P<0.001). The mean body mass index was 26.8 (26 in France to 27.5
in Finland, P<0.001). With regard to risk profile, diabetes was present
in 20.3% of patients (11.8% in Britain to 27.7% in Spain, P<0.001).
Chronic renal failure was present in 8.3% (6.8% in Germany to 10.6% in
Spain, P<0.001). Chronic airway disease affected 3.8% (1.9% in Italy to
5. 1% in Germany, P<0.001). The mean ejection fraction was 0.56 (0.48 in
Britain to 0.58 in Finland, P<0.001). The mean predicted mortality
(according to EuroSCORE) was 3.3% (2.8% in Finland to 3.6% in France,
P<0.001). The prevalence of chronic congestive heart failure, unstable
angina and recent myocardial infarction also showed statistically
significant differences. No differences were found for some critical
preoperative states (such as immediate preoperative cardiac massage and
pre-operative intubation), or for surgery for catheter laboratory
complication. Regarding surgical practice, major differences were noted in
preoperative intra-aortic balloon use (mean 1%, Finland 0%, Spain 2.3%,
P<0.001), the number of mammary artery conduits used (mean 0.9, Spain
0.7, France 1.1, P=0.0001) and the number of distal anastomoses (mean 3,
France 2.7, Finland 3.8, P=0.001). CONCLUSION: There are important
epidemiological differences in the national cohorts of CABG patients in the
EuroSCORE database. Any international comparison of European surgical
results must therefore take into account the risk profile of patients by
using a compatible risk stratification system.