[Preoperative cardiac risk evaluation of vascular surgery patients]

Abstract

Peripheral vascular surgery (carotid, infrainguinal or aortoiliacal) is characterised by an increased cardiac risk with an infarction rate of 1 to 4%. Sixty percent of the vascular patients present a concomitant coronary artery disease, often infraclinically. Preoperative cardiac risk stratification aims at reducing cardiac related morbidity and mortality. A clinical risk profile (patient's past history) and non-invasive cardiac tests allow subdividing the vascular patients into three categories: high risk, intermediate risk, and low risk. High-risk patients (unstable angina, recent infarction, overt congestive heart failure and critical aortic valve stenosis) require immediate intensive management of their underlying cardiac disease. This means delay or annulation of the planned vascular operation. For intermediate risk patients, a clinical cardiac risk index based on patient's past history (stable angina, previous infarction or episode of congestive heart failure, age of 70 years or more and diabetes) offers a rough orientation. These clinical markers lack specificity, since they are found in almost all vascular patients. The adjunction of a non-invasive cardiac testing allows to optimise the cardiac risk evaluation. Stress echocardiography with dobutamine has become a very popular test, with a negative predicting value exceeding 90%, but with a lack of specificity (many vascular patients have an uneventful postoperative outcome, despite a positive dobutamine test). These inconsistent results of cardiac risk evaluation render their routine use questionable. Nowadays, the management of patients requiring vascular surgery is based on the concept that every vascular patient should be considered as suffering from coronary artery disease. A certain degree of myocardial protection should be offered to every vascular surgery candidate. A preoperative treatment with betablockers provides myocardial protection against the operative stress and lowers myocardial oxygen requirement. There are arguments to continue or start aspirin treatment in the preoperative period, in order to lower the risk of sudden coronary thrombosis.