Trends during 25 years of coronary artery bypass operation at St. Luke's Medical Center in Milwaukee, Wisconsin

Background. Most studies of changes in coronary artery bypass graft (CABG) operations are from major academic institutions. The present study evaluated changes in CABG operations since 1968 in a community hospital. Methods. The data were from the St. Luke's Medical Center Cardiovascular Data Registry in Milwaukee, Wisconsin. Mortality rates, risk factors, overall patient risk, and surgical procedures were compared from 1968 to 1994. Results. There was a dramatic decrease in 30-day mortality rates from 1968 to 1972. After 1976, mortality rates increased because of higher risk patients, but the mortality rate, adjusted for patient risk, continued to decline. Both internal mammary arteries and sequential grafts were widely used by 1972, followed by a decline in use until 1980, and then a steep increase in use from 1980 to the present. Conclusions. This study provided evidence from a community hospital that the skills of the surgical teams improved first dramatically then gradually. The pattern of adapting new surgical techniques suggested that these techniques were critically evaluated for several years after they were introduced. (C) 2000 by The Society of Thoracic Surgeons.