Practical problems in assessing risk for coronary artery bypass grafting

In order to put results of a surgical program in proper perspective, risk factors for the population being treated should be carefully assessed. This paper discusses the practical problems involved in detemining the risk of surgical mortality for patients undergoing isolated coronary artery bypass grafting. A risk equation developed by the Collaborative Study in Coronary Artery Bypass was applied to a veterans hospital population. A simplified method of determining left ventricular function from clinical angiography reports was found to be a reasonable substitute for the more complex left ventricular scoring system used by the collaborative study. Results showed the veterans group to be at increased risk, primarily due to an older average age and higher incidence of left ventricular dysfunction.