Concordance of preoperative clinical risk with angiographic severity of coronary artery disease in patients undergoing vascular surgery

Background Preoperative clinical indexes to stratify cardiac risk have not been validated angiographically. Our aims were to determine the concordance of clinical risk with severity of coronary stenosis and to develop and validate a preoperative clinical index to exclude the presence of significant coronary stenosis. Methods and Results We carried out a prospective study of 878 consecutive patients (including the derivation and validation sets). ''Severe'' stenosis was defined as three-vessel (greater than or equal to 50% stenosis in each), two-vessel (greater than or equal to 50% stenosis in one when the other is greater than or equal to 70% stenosis of the left anterior descending), or left main disease (greater than or equal to 50%); ''critical'' stenosis was three-vessel (greater than or equal to 70% stenosis in each) and/or left main stenosis greater than or equal to 70%. A preoperative clinical index (diabetes mellitus, prior myocardial infarction, angina, age >70 years, congestive heart failure) was used to stratify patients. A gradient of risk for severe stenosis was seen with increasing numbers of clinical markers. The following prediction rules were developed: The absence of severe coronary stenoses can be predicted with a positive predictive value of 96% for patients who have no (1) history of diabetes, (2) prior angina, (3) previous myocardial infarction, or (4) history of congestive heart failure. The absence of critical coronary stenoses can be predicted with a positive predictive value of 94% for those who have no (1) prior angina, (2) previous myocardial infarction, or (3) history of congestive heart failure. Conclusions By reliably identifying a large proportion of patients with a low likelihood of significant stenoses, these prediction rules can help to substantially reduce healthcare costs associated with preoperative cardiac risk assessment for noncardiac surgery.