ABSTR ACT CASS includes a multiccnter patient registry and a randomized controlled
clinical trial. It is designed to assess the ell 'ect of coronary artery bypass surgery on mortality
and selected nonfatal end points. From August l975 to May 1979, 780 patients with stable
ischemic heart disease were randomly assigned to receive surgical (nr 390) or nonsurgical
(nz 390} treatment and were followed through April 15. 1983. At 5 years, the average annual
mortality rate in patients assigned to surgical treatment was 1.1%. The annual mortality rate …