[Individual risk assessment in aortocoronary bypass operation]

The treatment of coronary heart disease in open heart surgery shows the most increase since Favolora established in 1967 the aorto coronary bypass. Last year in Germany there had been 47 480 operations by using extracorporeal circulation. The individual advantages and risks of the bypass surgery are well known and discussed. But its difficult to explain the individual prognosis of the operation to the patient. To examine the survival rate after an aorto coronary bypass operation we used the Probit analyzing technique. The single and combined influence of the different parameters were examined by the Maximum-Likelihood method to estimate the value of each parameter. With this estimated values we calculated the individual risk using the formula based on the transformed standard deviation. Our examination includes 6122 patients revascularized 1983 and 1994. The multivarious analyze of the individual risks shows significant statistic values in the following parameters: left main stenosis, proximal RCA, RCX, and RIA stenosis, stenosis of peripheral RIA, NYHA class IV, existing kidney disease, peripheral arteriosclerosis, cardiac arrhythmias, quantity and location of myocardial infarction, emergency situations (e.g. after PTCA) and the age of the patient which shows a high significant value by a strong linear correlation.