Trends in cardiac surgery. Five-year study of a defined population.

The total number and types of cardiac operations performed on residents of Olmsted County, Minnesota, from 1973 through 1977 were studied through the use of the medical-records linkage system at the Mayo Clinic. During this time, 213 patients underwent 216 operations. The rates of cardiac operations per 10,000 population increased from 4.1 in 1973 to 5.9 in 1977. Operations other than for coronary artery bypass showed no significant trends over time, and the average rate was 2.5 per year. The incidence of coronary artery bypass operations increased from 1.5 in 1973 to 4.0 in 1977. On the basis of the rates for open-heart operations and under conditions similar to those in this community, a population of approximately 380,000 persons less than 15 years of age would be required to ensure 75 cases requiring open-heart operations per year, and a population of approximately 230,000 persons more than 14 years of age would provide 200 adult open-heart cases per year. Thus total populations of approximately 1,380,000 and 310,000 of all ages would be required to meet these minimum standards for pediatric and adult open-heart operations.