Dipyridamole-thallium scintigraphy predicts perioperative and long-term survival after major vascular surgery

The purpose of this study was to evaluate the ability of dipyridamole-thallium scintigraphy to predict perioperative and late cardiac events after peripheral vascular operations. A total of 262 patients had dipyridamole-thallium scintigraphy before 87 infrainguinal reconstructions, 108 abdominal aortic aneurysm operations, and 67 aortobifemoral bypass grafts that were placed for occlusive disease. Follow-up extended to 5 years (mean, 31.1 months). Logistic regression analysis selected dipyridamole-thallium scintigraphy redistribution as the best predictor of perioperative events. Fixed defects were not predictive. A Cox proportional hazards model for a variety of clinical risk factors and scan parameters identified fixed defects and a history of congestive heart failure as the strongest predictors of late cardiac events. The presence of greater than 1 or 2 fixed segments were the best predictors in patients with an abnormal scan; redistribution did not predict late events. The risk of combined perioperative or late cardiac events was 29% for infrainguinal, 19% for abdominal aortic aneurysm, and 7.5% for aortobifemoral operations. Life-table analysis showed that after a cluster of perioperative events that occurred primarily in patients with dipyridamole-thallium scintigraphy redistribution, most of the late cardiac morbidity and deaths occurred in patients with fixed defects.