Abdominal aortic aneurysms and concomitant coronary artery disease. Is routine dipyridamole thallium scintigraphy still justified?

There is a high prevalence of coronary artery disease in patients with peripheral vascular disease (PVD). Following elective abdominal aortic aneurysm (AAA) repair the commonest cause for perioperative death is cardiac-related. Patients at high risk of developing perioperative adverse cardiac events can be identified. Means of identification include clinical history and examination with or without the calculation of a scoring index, stress testing and measurement of ejection fractions. The use of dipyridamole thallium scanning (DTS) in patients with PVD results in about 1/3 of patients having normal scans, 1/3 showing reversible and 1/3 fixed defects. It has been generally accepted that fixed defects represent a completed myocardial infarction and patients are at no greater risk of developing perioperative cardiac complications than those patients with normal scans. However, delayed scans show that some of these "fixed" defects are in fact reversible. Evidence of a redistribution defect implies myocardial ischaemia. The debate centres on whether identification of such defects and their correction will improve perioperative mortality following AAA repair. There is no evidence that identification and correcting coronary artery disease in asymptomatic patients results either in improved operative mortality or long-term survival. "Routine" use of DTS or any other means of cardiac investigation cannot be justified. Patients who clinically fall into a "high risk" category perhaps should be investigated but a case could be made for simply optimising their medical treatment and not carrying out either coronary revascularisation or aneurysm repair.