[Preoperative evaluation of coronary circulation]

Abstract

It is not easy to define a plan for the preoperative assessment of the coronary circulation: some studies carried out in the context of vascular surgery are contradictory and no method has a sensitivity and specificity of 100%. Nevertheless, it is essential to select patients with a high risk of perioperative cardiac complications so that their medical treatment can be reinforced or anatomical correction envisaged. A first assessment is obtained from the history, the clinical examination and simple investigations (resting ECG, chest X-ray). Surgical operations which do not impose a major strain on the cardiovascular system do not require further investigations. The risk of postoperative cardiac complications is low in the absence of the nine risk factors defined by Goldman and/or an ischemic syndrome (residual angina after mild physical activity, unstable angina, myocardial infarct). The problem arises in patients with the Goldman risk factors and/or a history of coronary insufficiency and/or coronary insufficiency risk factors (diabetes, tobacco, hypercholesterolemia, age > 70 years, arterial hypertension), who require an operation likely to cause a particularly serious strain on the cardiovascular system. An exercise ECG, by the Holter method, is helpful, particularly in known or potential coronary arteriopaths who cannot exercise. Echocardiography under dobutamine has good sensitivity and good specificity when exercise is impossible. Thallium-dipyridamole scanning has not been shown to be helpful in vascular surgery. This method could be refined by a quantitative analysis of the number of areas and segments involved. Finally, patients showing ischaemic changes on continuous ECG recording, abnormalities on echocardiography under dobutamine, abnormalities on thallium-dipyridamole myocardial scanning or on exercise ECG, should be considered for coronary angiography with a view to a preliminary anatomical correction.