Evaluation of Exercise Thallium Scintigraphy Versus Exercise Electrocardiography in Predicting Survival Outcomes and Morbid Cardiac Events in Patients With Single- and Double-Vessel Disease

Objectives. We sought to evaluate the prognostic ability of cardiac exercise stress tests in predicting cardiac mortality and morbidity in a low risk group of patients with established coronary artery disease (CAD). Background. Although previous studies have demonstrated the superior value of stress nuclear cardiac scintigraphy in the prognosis of patients with CAD, none of these studies have focused on patients with a proven angiographic low risk profile (i.e., singleand double-vessel CAD). Methods. Three hundred twenty-eight patients with documented singleand double-vessel disease were treated by random assignment to percutaneous transluminal coronary angioplasty or medical therapy in the Angioplasty Compared to Medicine (ACME) trial. Six months after randomization, maximal symptom-limited exercise tests were performed with electrocardiography (n 5 300) and thallium scintigraphy (n 5 270). Patients were followed up for a minimum of 5 years thereafter. Results. A reversible thallium perfusion deficit documented after 6 months of either therapy was associated with an adverse mortality outcome (18% mortality rate with a reversible thallium perfusion defect and 8% mortality rate with no reversible thallium perfusion deficit, p 5 0.02). Moreover, an important mortality gradient was demonstrated in relation to the number of reperfusing defects (0 5 7%, 1 to 2 5 15%, >3 5 20%, p 5 0.04). Exercise electrocardiography did not predict this mortality outcome. Conclusions. A reversible thallium perfusion deficit demonstrated 6 months after medical therapy or coronary angioplasty is a valuable prognostic marker in patients with angiographically documented singleand double-vessel disease and is superior to exercise electrocardiography in this regard. (J Am Coll Cardiol 1997;30:1256–63) ©1997 by the American College of Cardiology