Natural history of obstructive coronary artery disease: ten-year study of 601 nonsurgical cases.

The most important factors in the prognosis of coronary artery disease are the number of arteries severly obstructed, significant involvement of the left main coronary artery, and generalized impairment of left ventricular function or ventricular aneurysm. Other prognostic influences at least partially independent of these factors are the severity of functional impairment imposed by angina pectoris, electrocardiographic evidence of left ventricular hypertrophy or conduction defects, hypertension, and diabetes. Candidates for bypass operation have a better prognosis than noncandidates, but difference in left ventricular function is responsible. Refinement of prognostic precision will depend largely on future improvement in measurement of obstructive disease and left ventricular function serially and better knowledge of the cause or causes of coronary artery disease.